000
FXUS61 KBUF 201514
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1014 AM EST TUE JAN 20 2009
.SYNOPSIS...
A NORTHWEST FLOW OF VERY COLD AIR WILL PERSIST ACROSS THE REGION
TODAY BETWEEN LOW PRESSURE WELL OFF THE EAST COAST AND A RIDGE OF
HIGH PRESSURE MOVING EASTWARD INTO THE MISSISSIPPI VALLEY. THIS WILL
KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION TODAY AND FOR AWHILE
TONIGHT...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
ACTIVITY ON BUF RADAR BRIEFLY INTENSIFIED TO THE NORTH OF
BUF-BATAVIA LINE THIS MRNG BUT SINCE ARND 1430Z SHOWING SIGNS OF
WEAKENING. WILL CONTINUE TREND OF EARLIER FORECAST TO DROP POPS TO
CHC/LKLY RANGE SE OF THE LAKES THIS AFTERNOON. ADDITONAL ACCUMS THIS
AFTN GENLY AN INCH OR LESS.
EARLIER DISCUSSION BELOW.
WEAK TROUGH OF LOW PRESSURE ACROSS THE EASTERN GREAT LAKES AND NEW
YORK STATE WILL FILL TODAY. BOUNDARY LAYER WINDS ACROSS THE LAKES
WILL BE GENERALLY FROM THE NORTHWEST WHICH WILL BRING SHALLOW LAKE
MOISTENED AIR ACROSS THE FORECAST AREA. AS 850MB TEMPS REMAIN IN THE
-14C TO -16C RANGE...WE CAN EXPECT LIGHT LAKE EFFECT SNOW TO COVER A
LARGE PORTION OF THE REGION...MAINLY OFF LAKE ONTARIO. LESS MOISTURE
AND LIFT FROM LAKE ERIE DUE TO MOSTLY ICE COVERED LAKE SURFACE WILL
LIMIT LAKE SNOW OVER THE WESTERN SOUTHERN TIER...BUT WILL KEEP LOW
LIKELY POPS THERE AS UPSLOPE EFFECTS OF THE TERRAIN SHOULD WRING OUT
ANY AVAILABLE MOISTURE AS LIGHT SNOW. ACCUMULATIONS WILL RANGE FROM
ONLY A FEW TENTHS OF AN INCH TO AN INCH OR SO EVERY 6
HOURS...GENERALLY 1 TO 2 INCHES OVERALL FOR TODAY THROUGH TONIGHT.
TEMPS WILL BE A LITTLE COLDER TODAY THAN ON MONDAY AS THE
NORTH/NORTHWEST WINDS AND LAKE INDUCED CLOUDS WILL NOT OFFER MUCH
WARMING DURING THE DAY. SOME PARTIALLY SUNNY SPOTS AROUND THE FINGER
LAKES AND THE GENESEE VALLEY MAY REACH CLOSE TO 20...AS WILL THE
LAKE ONTARIO SHORELINE LOCATIONS WITH MODERATION FROM THE WARMER
LAKE WATER.
LOWS TONIGHT WILL RANGE MOSTLY WITHIN THE SINGLE NUMBERS...IN THE
TEENS RIGHT ALONG THE LAKE ONTARIO SHORE WITH MORE CLOUDINESS AND
INFLUENCE OF WARMER LAKE WATER. THE COLDER SPOTS OF THE SOUTHERN
TIER WILL BE IN THE LOWER SINGLE DIGITS...AND THE EASTERN LAKE
ONTARIO REGION WILL LIKELY FALL BELOW ZERO...BOTH COLDER AREAS
LACKING THE LAKE INDUCED CLOUD COVER.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
CONTINUITY FOR WEDNESDAY HAS A CHANCE OF SNOW SHOWERS AS A SURFACE
RIDGE MOVES EAST OF OUR REGION AND A TROUGH OF LOW PRESSURE TRACKS
EASTWARD ACROSS THE GREAT LAKES AND EASTERN ONTARIO PROVINCE.
STEERING WINDS WILL BACK TO WESTERLY AS THE TROUGH APPROACHES AND
ISENTROPIC LIFT WILL HELP MOISTEN THE LOWER AND MID LEVELS OF THE
ATMOSPHERE DURING THE DAY. WE ARE A LITTLE MORE CONCERNED WITH LAKE
EFFECT EAST OF THE LAKES THAN WE WERE YESTERDAY. WE WILL THROW SOME
LIKELY POPS IN EAST AND NORTHEAST OF THE LAKES BUT IT STILL LOOKS
LIKE ANY ACCUMULATIONS WOULD BE MINOR. PROJECTED SOUNDINGS SHOW JUST
ENOUGH LAKE INDUCED CAPE WITH EQUILIBRIUM LEVELS AROUND 4 THOUSAND
FEET EAST OF LAKE ERIE AND AROUND 6 THOUSAND FEET EAST OF LAKE
ONTARIO. WE ARE ALSO CONCERNED THAT THE LAKE EFFECT ACTIVITY WILL
MOVE AS FAR NORTH AS THE BUFFALO AND WATERTOWN AREAS SINCE THE FLOW
BENEATH THE EQUILIBRIUM LEVEL IS 240-250 DEGREES.
ISENTROPIC LIFT WILL CONTINUE WEDNESDAY NIGHT BUT THIS WILL LOWER
THE EQUILIBRIUM LEVEL FURTHER. THIS PATTERN SHOULD MAINTAIN THE
POTENTIAL FOR SOME LIMITED SNOWS ACROSS THE ENTIRE AREA BUT LAKE
ENHANCEMENT WILL BE DIMINISHED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 20C OR COLDER OVER THE COURSE OF THE WEEKEND SHOULD
GENERATE SOME LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR
WILL BE ADVECTION OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR
NOW...WILL KEEP LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER
GUIDANCE MAY SUGGEST BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER
TO THE TUG HILL.
EARLY NEXT WEEK THE GFS AND ECMWF UPPER AIR PATTERNS ARE SIMILAR BUT
THERE ARE SOME PRETTY BIG DIFFERENCES FOR THE SURFACE PATTERN. BY
MONDAY EVENING THE ECMWF HAS A SURFACE HIGH SPRAWLED FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY WHEREAS THE GFS HAS A 1009 MB LOW
MOVING NORTHEAST INTO THE OHIO VALLEY WITH A STRONG 1040 MB HIGH
CENTERED OVER QUEBEC. NEEDLESS TO SAY THERE ARE SOME CONFIDENSE
ISSUES LATE IN THE THIS PERIOD.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE MORE
VERY COLD AIR ACROSS THE EASTERN GREAT LAKES TODAY. THIS COLD
CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS THE MAJORITY OF
WESTERN NEW YORK THROUGH MUCH OF TODAY WITH CIGS RANGING FROM 2500
TO 3500 FT AND VSBYS OCCASIONALLY FALLING TO BETWEEN 2 AND 5 SM IN
LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE THIS AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TONIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...JJP/WCH
SHORT TERM...SAGE
LONG TERM...SAGE/TMA
AVIATION...RSH/WCH
MARINE...SAGE/TMA
000
FXUS61 KBUF 201226
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
726 AM EST TUE JAN 20 2009
.SYNOPSIS...
A NORTHWEST FLOW OF VERY COLD AIR WILL PERSIST ACROSS THE REGION
TODAY BETWEEN LOW PRESSURE WELL OFF THE EAST COAST AND A RIDGE OF
HIGH PRESSURE MOVING EASTWARD INTO THE MISSISSIPPI VALLEY. THIS WILL
KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION TODAY AND FOR AWHILE
TONIGHT...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK TROUGH OF LOW PRESSURE ACROSS THE EASTERN GREAT LAKES AND NEW
YORK STATE WILL FILL TODAY. BOUNDARY LAYER WINDS ACROSS THE LAKES
WILL BE GENERALLY FROM THE NORTHWEST WHICH WILL BRING SHALLOW LAKE
MOISTENED AIR ACROSS THE FORECAST AREA. AS 850MB TEMPS REMAIN IN THE
-14C TO -16C RANGE...WE CAN EXPECT LIGHT LAKE EFFECT SNOW TO COVER A
LARGE PORTION OF THE REGION...MAINLY OFF LAKE ONTARIO. LESS MOISTURE
AND LIFT FROM LAKE ERIE DUE TO MOSTLY ICE COVERED LAKE SURFACE WILL
LIMIT LAKE SNOW OVER THE WESTERN SOUTHERN TIER...BUT WILL KEEP LOW
LIKELY POPS THERE AS UPSLOPE EFFECTS OF THE TERRAIN SHOULD WRING OUT
ANY AVAILABLE MOISTURE AS LIGHT SNOW. ACCUMULATIONS WILL RANGE FROM
ONLY A FEW TENTHS OF AN INCH TO AN INCH OR SO EVERY 6
HOURS...GENERALLY 1 TO 2 INCHES OVERALL FOR TODAY THROUGH TONIGHT.
TEMPS WILL BE A LITTLE COLDER TODAY THAN ON MONDAY AS THE
NORTH/NORTHWEST WINDS AND LAKE INDUCED CLOUDS WILL NOT OFFER MUCH
WARMING DURING THE DAY. SOME PARTIALLY SUNNY SPOTS AROUND THE FINGER
LAKES AND THE GENESEE VALLEY MAY REACH CLOSE TO 20...AS WILL THE
LAKE ONTARIO SHORELINE LOCATIONS WITH MODERATION FROM THE WARMER
LAKE WATER.
LOWS TONIGHT WILL RANGE MOSTLY WITHIN THE SINGLE NUMBERS...IN THE
TEENS RIGHT ALONG THE LAKE ONTARIO SHORE WITH MORE CLOUDINESS AND
INFLUENCE OF WARMER LAKE WATER. THE COLDER SPOTS OF THE SOUTHERN
TIER WILL BE IN THE LOWER SINGLE DIGITS...AND THE EASTERN LAKE
ONTARIO REGION WILL LIKELY FALL BELOW ZERO...BOTH COLDER AREAS
LACKING THE LAKE INDUCED CLOUD COVER.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
CONTINUITY FOR WEDNESDAY HAS A CHANCE OF SNOW SHOWERS AS A SURFACE
RIDGE MOVES EAST OF OUR REGION AND A TROUGH OF LOW PRESSURE TRACKS
EASTWARD ACROSS THE GREAT LAKES AND EASTERN ONTARIO PROVINCE.
STEERING WINDS WILL BACK TO WESTERLY AS THE TROUGH APPROACHES AND
ISENTROPIC LIFT WILL HELP MOISTEN THE LOWER AND MID LEVELS OF THE
ATMOSPHERE DURING THE DAY. WE ARE A LITTLE MORE CONCERNED WITH LAKE
EFFECT EAST OF THE LAKES THAN WE WERE YESTERDAY. WE WILL THROW SOME
LIKELY POPS IN EAST AND NORTHEAST OF THE LAKES BUT IT STILL LOOKS
LIKE ANY ACCUMULATIONS WOULD BE MINOR. PROJECTED SOUNDINGS SHOW JUST
ENOUGH LAKE INDUCED CAPE WITH EQUILIBRIUM LEVELS AROUND 4 THOUSAND
FEET EAST OF LAKE ERIE AND AROUND 6 THOUSAND FEET EAST OF LAKE
ONTARIO. WE ARE ALSO CONCERNED THAT THE LAKE EFFECT ACTIVITY WILL
MOVE AS FAR NORTH AS THE BUFFALO AND WATERTOWN AREAS SINCE THE FLOW
BENEATH THE EQUILIBRIUM LEVEL IS 240-250 DEGREES.
ISENTROPIC LIFT WILL CONTINUE WEDNESDAY NIGHT BUT THIS WILL LOWER
THE EQUILIBRIUM LEVEL FURTHER. THIS PATTERN SHOULD MAINTAIN THE
POTENTIAL FOR SOME LIMITED SNOWS ACROSS THE ENTIRE AREA BUT LAKE
ENHANCEMENT WILL BE DIMINISHED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 20C OR COLDER OVER THE COURSE OF THE WEEKEND SHOULD
GENERATE SOME LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR
WILL BE ADVECTION OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR
NOW...WILL KEEP LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER
GUIDANCE MAY SUGGEST BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER
TO THE TUG HILL.
EARLY NEXT WEEK THE GFS AND ECMWF UPPER AIR PATTERNS ARE SIMILAR BUT
THERE ARE SOME PRETTY BIG DIFFERENCES FOR THE SURFACE PATTERN. BY
MONDAY EVENING THE ECMWF HAS A SURFACE HIGH SPRAWLED FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY WHEREAS THE GFS HAS A 1009 MB LOW
MOVING NORTHEAST INTO THE OHIO VALLEY WITH A STRONG 1040 MB HIGH
CENTERED OVER QUEBEC. NEEDLESS TO SAY THERE ARE SOME CONFIDENSE
ISSUES LATE IN THE THIS PERIOD.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE MORE
VERY COLD AIR ACROSS THE EASTERN GREAT LAKES TODAY. THIS COLD
CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS THE MAJORITY OF
WESTERN NEW YORK THROUGH MUCH OF TODAY WITH CIGS RANGING FROM 2500
TO 3500 FT AND VSBYS OCCASIONALLY FALLING TO BETWEEN 2 AND 5 SM IN
LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE THIS AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TONIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...SAGE/TMA
AVIATION...RSH/WCH
MARINE...SAGE/TMA
000
FXUS61 KBUF 200832
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
332 AM EST TUE JAN 20 2009
.SYNOPSIS...
A NORTHWEST FLOW OF VERY COLD AIR WILL PERSIST ACROSS THE REGION
TODAY BETWEEN LOW PRESSURE WELL OFF THE EAST COAST AND A RIDGE OF
HIGH PRESSURE MOVING EASTWARD INTO THE MISSISSIPPI VALLEY. THIS WILL
KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION TODAY AND FOR AWHILE
TONIGHT...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK TROUGH OF LOW PRESSURE ACROSS THE EASTERN GREAT LAKES AND NEW
YORK STATE WILL FILL TODAY. BOUNDARY LAYER WINDS ACROSS THE LAKES
WILL BE GENERALLY FROM THE NORTHWEST WHICH WILL BRING SHALLOW LAKE
MOISTENED AIR ACROSS THE FORECAST AREA. AS 850MB TEMPS REMAIN IN THE
-14C TO -16C RANGE...WE CAN EXPECT LIGHT LAKE EFFECT SNOW TO COVER A
LARGE PORTION OF THE REGION...MAINLY OFF LAKE ONTARIO. LESS MOISTURE
AND LIFT FROM LAKE ERIE DUE TO MOSTLY ICE COVERED LAKE SURFACE WILL
LIMIT LAKE SNOW OVER THE WESTERN SOUTHERN TIER...BUT WILL KEEP LOW
LIKELY POPS THERE AS UPSLOPE EFFECTS OF THE TERRAIN SHOULD WRING OUT
ANY AVAILABLE MOISTURE AS LIGHT SNOW. ACCUMULATIONS WILL RANGE FROM
ONLY A FEW TENTHS OF AN INCH TO AN INCH OR SO EVERY 6
HOURS...GENERALLY 1 TO 2 INCHES OVERALL FOR TODAY THROUGH TONIGHT.
TEMPS WILL BE A LITTLE COLDER TODAY THAN ON MONDAY AS THE
NORTH/NORTHWEST WINDS AND LAKE INDUCED CLOUDS WILL NOT OFFER MUCH
WARMING DURING THE DAY. SOME PARTIALLY SUNNY SPOTS AROUND THE FINGER
LAKES AND THE GENESEE VALLEY MAY REACH CLOSE TO 20...AS WILL THE
LAKE ONTARIO SHORELINE LOCATIONS WITH MODERATION FROM THE WARMER
LAKE WATER.
LOWS TONIGHT WILL RANGE MOSTLY WITHIN THE SINGLE NUMBERS...IN THE
TEENS RIGHT ALONG THE LAKE ONTARIO SHORE WITH MORE CLOUDINESS AND
INFLUENCE OF WARMER LAKE WATER. THE COLDER SPOTS OF THE SOUTHERN
TIER WILL BE IN THE LOWER SINGLE DIGITS...AND THE EASTERN LAKE
ONTARIO REGION WILL LIKELY FALL BELOW ZERO...BOTH COLDER AREAS
LACKING THE LAKE INDUCED CLOUD COVER.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
CONTINUITY FOR WEDNESDAY HAS A CHANCE OF SNOW SHOWERS AS A SURFACE
RIDGE MOVES EAST OF OUR REGION AND A TROUGH OF LOW PRESSURE TRACKS
EASTWARD ACROSS THE GREAT LAKES AND EASTERN ONTARIO PROVINCE.
STEERING WINDS WILL BACK TO WESTERLY AS THE TROUGH APPROACHES AND
ISENTROPIC LIFT WILL HELP MOISTEN THE LOWER AND MID LEVELS OF THE
ATMOSPHERE DURING THE DAY. WE ARE A LITTLE MORE CONCERNED WITH LAKE
EFFECT EAST OF THE LAKES THAN WE WERE YESTERDAY. WE WILL THROW SOME
LIKELY POPS IN EAST AND NORTHEAST OF THE LAKES BUT IT STILL LOOKS
LIKE ANY ACCUMULATIONS WOULD BE MINOR. PROJECTED SOUNDINGS SHOW JUST
ENOUGH LAKE INDUCED CAPE WITH EQUILIBRIUM LEVELS AROUND 4 THOUSAND
FEET EAST OF LAKE ERIE AND AROUND 6 THOUSAND FEET EAST OF LAKE
ONTARIO. WE ARE ALSO CONCERNED THAT THE LAKE EFFECT ACTIVITY WILL
MOVE AS FAR NORTH AS THE BUFFALO AND WATERTOWN AREAS SINCE THE FLOW
BENEATH THE EQUILIBRIUM LEVEL IS 240-250 DEGREES.
ISENTROPIC LIFT WILL CONTINUE WEDNESDAY NIGHT BUT THIS WILL LOWER
THE EQUILIBRIUM LEVEL FURTHER. THIS PATTERN SHOULD MAINTAIN THE
POTENTIAL FOR SOME LIMITED SNOWS ACROSS THE ENTIRE AREA BUT LAKE
ENHANCEMENT WILL BE DIMINISHED.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 20C OR COLDER OVER THE COURSE OF THE WEEKEND SHOULD
GENERATE SOME LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR
WILL BE ADVECTION OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR
NOW...WILL KEEP LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER
GUIDANCE MAY SUGGEST BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER
TO THE TUG HILL.
EARLY NEXT WEEK THE GFS AND ECMWF UPPER AIR PATTERNS ARE SIMILAR BUT
THERE ARE SOME PRETTY BIG DIFFERENCES FOR THE SURFACE PATTERN. BY
MONDAY EVENING THE ECMWF HAS A SURFACE HIGH SPRAWLED FROM THE
NORTHERN PLAINS TO THE OHIO VALLEY WHEREAS THE GFS HAS A 1009 MB LOW
MOVING NORTHEAST INTO THE OHIO VALLEY WITH A STRONG 1040 MB HIGH
CENTERED OVER QUEBEC. NEEDLESS TO SAY THERE ARE SOME CONFIDENSE
ISSUES LATE IN THE THIS PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE MORE
VERY COLD AIR ACROS THE EASTERN GREAT LAKES OVERNIGHT AND TUESDAY.
THIS COLD CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS THE
MAJORITY OF WESTERN NEW YORK OVERNIGHT THROUGH MUCH OF TUESDAY WITH
CIGS RANGING FROM 2500 TO 3500 FT AND VSBYS OCCASIONALLY FALLING TO
BETWEEN 3 AND 5 SM IN LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE TUESDAY AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TONIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...SAGE/TMA
AVIATION...HITCHCOCK/RSH
MARINE...SAGE/TMA
000
FXUS61 KBUF 200442
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1142 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE ANOTHER
BATCH OF VERY COLD AIR ACROSS NEW YORK STATE. THIS WILL KEEP
SCATTERED SNOW SHOWERS ACROSS THE REGION THROUGH TUESDAY...
ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING TREND IS THEN
EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE END OF THE
WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE WEAK SURFACE FEATURE THAT HAS BEEN BRINGING LIGHT SNOW TO MUCH
OF WESTERN/NORTH CENTRAL NEW YORK FOR THE PAST 36 HOURS IS NOW
EXITING ACROSS THE ADIRONDACKS. VERY COLD AIR IN ITS WAKE IS NOW
BEING CIRCULATED ACROSS LAKES ERIE AND ONTARIO...AND AS ONE WOULD
EXPECT AT THIS TIME OF YEAR...WIDESPREAD LAKE EFFECT SNOW SHOWERS
ARE BEING PRODUCED.
WHILE SCT SNOW SHOWERS CAN BE EXPECTED ACROSS ALL OF THE FORECAST
AREA OVERNIGHT...THE LAKE SNOWS WILL BE MOST COMMON ACROSS THE
COUNTIES BORDERING THE SOUTH SHORE OF LAKE ONTARIO. FROM THE NIAGARA
RICVER TO OSWEGO COUNTY...LAKE SNOWS ARE EXPECTED TO ACCUMULATE 1 TO
3 INCHES OVERNIGHT. GIVEN THAT THE AIRMASS IS VERY COLD...THE SNOW
WILL ONCE AGAIN BE VERY DENSE...PLATELETS THAT WILL MAKE IT
PARTICULARLY SLICK FOR DRIVING AS ROADS WILL BECOME SNOW COVERED AND
`GREASY`.
TEMPS FOR THE OVERNIGHT HAVE BEEN LOWERED A FEW DEGREES
REGIONWIDE...AND LOOKING AT UPSTREAM (SRN ONTARIO/WRN QUEBEC) MAX
TEMPS FROM TODAY (MON)...HAVE DECIDED TO ADJUST OUR TUESDAY MAX`S
DOWN AS WELL. THIS DOWNWARD MOVE IS SUPPORTED BY THE NEW GUIDANCE
THAT IS JUST HITTING THE STREET...AND HAS BEEN SUPPORTED FOR THE
PAST SEVERAL RUNS OF THE GFS BASED LAMP GUIDANCE. AS A RESULT...
TEMPS TUESDAY WILL ONLY CLIMB INTO THE TEENS RATHER THAN THE LOWER
20S. THE EXCEPTION TO THIS MAY BE RIGHT ALONG THE SOUTH SHORE OF LK
ONTARIO.
AS FOR THE LAKE EFFECT SOUTHEAST OF LK ERIE...DESPITE THE ORTHOGONAL
FLOW TOT HE CHAUTAUQUA RIDGE...THE AMOUNT OF OPEN WATER APPEARS TO
BE REALLY ADVERSELY AFFECTING THE SUPPORT FOR WIDESPREAD LAKE SNOW
SHOWERS. THE LAKE IS OVER 90 PERCENT ICE COVERED AND THE FETCH IS
VERY SHORT (NW FLOW)...HENCE THE UNIMPRESSIVE RADAR RETURNS.
ON TUESDAY MORNING THE BOUNDARY LAYER FLOW WILL BECOME RE-ALIGNED ON
A 340 VECTOR. DECENT INSTABILITY REMAINS IN PLACE...AND SHOULD BE
FAVORABLE FOR PLENTY OF LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF
WESTERN AND CENTRAL NEW YORK TO THE SOUTH AND SOUTHEAST OF LAKE
ONTARIO. OUR LOCAL 6KM WRF SUPPORTS THIS SCENARIO AS WELL. UPSLOPE
FLOW ACROSS THE SOUTHERN TIER AND FINGER LAKES SHOULD SUPPORT THE
LAKE EFFECT SNOW SHOWERS WELL INLAND. WILL GO WITH LIKELY POPS AGAIN
ACROSS MUCH OF THE AREA DURING THE MORNING HOURS. BY AFTERNOON THE
FLOW BACKS MORE TO 310-320 DEGREES...WHICH WILL FOCUS ANY REMAINING
ACTIVITY TO THE SOUTHEAST OF THE LAKE IN AREAS BETWEEN ROCHESTER AND
OSWEGO.
AS FAR AS AMOUNTS GO...EXPECT ANOTHER 1 TO 2 INCHES TUESDAY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
MINOR LAKE SNOWS SHOULD BE ONGOING AT THE START OF THE PERIOD AS 850
MB TEMPERATURES BETWEEN MINUS 12C AND MINUS 14C CONTINUE ON A
NORTHWEST FLOW. THE SURFACE RIDGE IS EXPECTED TO CREST OVER THE
REGION LATE TUESDAY NIGHT...BUT THE 850 MB RIDGE REMAINS JUST TO THE
WEST THROUGH AT LEAST WEDNESDAY MORNING...THEREFORE ANY LAKE SNOWS
SHOULD CONTINUE INTO THE FIRST HALF OF WEDNESDAY SOUTHEAST OF THE
LAKES. SOME WEAK ISENTROPIC UPGLIDE WILL DEVELOP ACROSS THE AREA AS
THE HIGH SHIFTS EAST OF THE AREA LATER WEDNESDAY AND WEDNESDAY NIGHT
AS A WEAK WARM AIR ADVECTION PATTERN FOCUSES ON THE AREA. THIS
PATTERN SHOULD MAINTAIN THE POTENTIAL FOR SOME LIMITED SNOWS ACROSS
THE ENTIRE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C OVER THE COURSE OF THE WEEKEND SHOULD GENERATE SOME
LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR WILL BE ADVECTION
OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR NOW...WILL KEEP
LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER GUIDANCE MAY SUGGEST
BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER TO THE TUG HILL.
GFS/ECMWF SUGGESTING POTENTIAL FOR BACKING FLOW LATE SUNDAY AND
MONDAY WHICH WOULD BRING ANY LAKE SNOWS NORTHWARD...POTENTIALLY
IMPACTING THE BUFFALO/WATERTOWN AREAS. STAY TUNED.
MORE SEASONABLE TEMPERATURES SHOULD BE THE CASE IN THE LESS
AMPLIFIED FLOW AT THE START OF THE PERIOD...BUT SHOULD DROP WELL
BELOW NORMAL LEVELS AS THE REINFORCING SHOT OF ARCTIC AIR WORKS INTO
THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE MORE
VERY COLD AIR ACROS THE EASTERN GREAT LAKES OVERNIGHT AND TUESDAY.
THIS COLD CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS THE
MAJORITY OF WESTERN NEW YORK OVERNIGHT THROUGH MUCH OF TUESDAY WITH
CIGS RANGING FROM 2500 TO 3500 FT AND VSBYS OCCASIONALLY FALLING TO
BETWEEN 3 AND 5 SM IN LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE TUESDAY AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TUESDAY NIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH
NEAR TERM...HITCHCOCK/RSH
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK/RSH
MARINE...TMA
000
FXUS61 KBUF 200314
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1014 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE EXITING ACROSS THE ADIRONDACKS WILL CIRCULATE ANOTHER
BATCH OF VERY COLD AIR ACROSS NEW YORK STATE. THIS WILL KEEP
SCATTERED SNOW SHOWERS ACROSS THE REGION THROUGH TUESDAY...
ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING TREND IS THEN
EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE END OF THE
WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE WEAK SURFACE FEATURE THAT HAS BEEN BRINGING LIGHT SNOW TO MUCH
OF WESTERN/NORTH CENTRAL NEW YORK FOR THE PAST 36 HOURS IS NOW
EXITING ACROSS THE ADIRONDACKS. VERY COLD AIR IN ITS WAKE IS NOW
BEING CIRCULATED ACROSS LAKES ERIE AND ONTARIO...AND AS ONE WOULD
EXPECT AT THIS TIME OF YEAR...WIDESPREAD LAKE EFFECT SNOW SHOWERS
ARE BEING PRODUCED.
WHILE SCT SNOW SHOWERS CAN BE EXPECTED ACROSS ALL OF THE FORECAST
AREA OVERNIGHT...THE LAKE SNOWS WILL BE MOST COMMON ACROSS THE
COUNTIES BORDERING THE SOUTH SHORE OF LAKE ONTARIO. FROM THE NIAGARA
RICVER TO OSWEGO COUNTY...LAKE SNOWS ARE EXPECTED TO ACCUMULATE 1 TO
3 INCHES OVERNIGHT. GIVEN THAT THE AIRMASS IS VERY COLD...THE SNOW
WILL ONCE AGAIN BE VERY DENSE...PLATELETS THAT WILL MAKE IT
PARTICULARLY SLICK FOR DRIVING AS ROADS WILL BECOME SNOW COVERED AND
`GREASY`.
TEMPS FOR THE OVERNIGHT HAVE BEEN LOWERED A FEW DEGREES
REGIONWIDE...AND LOOKING AT UPSTREAM (SRN ONTARIO/WRN QUEBEC) MAX
TEMPS FROM TODAY (MON)...HAVE DECIDED TO ADJUST OUR TUESDAY MAX`S
DOWN AS WELL. THIS DOWNWARD MOVE IS SUPPORTED BY THE NEW GUIDANCE
THAT IS JUST HITTING THE STREET...AND HAS BEEN SUPPORTED FOR THE
PAST SEVERAL RUNS OF THE GFS BASED LAMP GUIDANCE. AS A RESULT...
TEMPS TUESDAY WILL ONLY CLIMB INTO THE TEENS RATHER THAN THE LOWER
20S. THE EXCEPTION TO THIS MAY BE RIGHT ALONG THE SOUTH SHORE OF LK
ONTARIO.
AS FOR THE LAKE EFFECT SOUTHEAST OF LK ERIE...DESPITE THE ORTHOGONAL
FLOW TOT HE CHAUTAUQUA RIDGE...THE AMOUNT OF OPEN WATER APPEARS TO
BE REALLY ADVERSELY AFFECTING THE SUPPORT FOR WIDESPREAD LAKE SNOW
SHOWERS. THE LAKE IS OVER 90 PERCENT ICE COVERED AND THE FETCH IS
VERY SHORT (NW FLOW)...HENCE THE UNIMPRESSIVE RADAR RETURNS.
ON TUESDAY MORNING THE BOUNDARY LAYER FLOW WILL BECOME RE-ALIGNED ON
A 340 VECTOR. DECENT INSTABILITY REMAINS IN PLACE...AND SHOULD BE
FAVORABLE FOR PLENTY OF LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF
WESTERN AND CENTRAL NEW YORK TO THE SOUTH AND SOUTHEAST OF LAKE
ONTARIO. OUR LOCAL 6KM WRF SUPPORTS THIS SCENARIO AS WELL. UPSLOPE
FLOW ACROSS THE SOUTHERN TIER AND FINGER LAKES SHOULD SUPPORT THE
LAKE EFFECT SNOW SHOWERS WELL INLAND. WILL GO WITH LIKELY POPS AGAIN
ACROSS MUCH OF THE AREA DURING THE MORNING HOURS. BY AFTERNOON THE
FLOW BACKS MORE TO 310-320 DEGREES...WHICH WILL FOCUS ANY REMAINING
ACTIVITY TO THE SOUTHEAST OF THE LAKE IN AREAS BETWEEN ROCHESTER AND
OSWEGO.
AS FAR AS AMOUNTS GO...EXPECT ANOTHER 1 TO 2 INCHES TUESDAY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
MINOR LAKE SNOWS SHOULD BE ONGOING AT THE START OF THE PERIOD AS 850
MB TEMPERATURES BETWEEN MINUS 12C AND MINUS 14C CONTINUE ON A
NORTHWEST FLOW. THE SURFACE RIDGE IS EXPECTED TO CREST OVER THE
REGION LATE TUESDAY NIGHT...BUT THE 850 MB RIDGE REMAINS JUST TO THE
WEST THROUGH AT LEAST WEDNESDAY MORNING...THEREFORE ANY LAKE SNOWS
SHOULD CONTINUE INTO THE FIRST HALF OF WEDNESDAY SOUTHEAST OF THE
LAKES. SOME WEAK ISENTROPIC UPGLIDE WILL DEVELOP ACROSS THE AREA AS
THE HIGH SHIFTS EAST OF THE AREA LATER WEDNESDAY AND WEDNESDAY NIGHT
AS A WEAK WARM AIR ADVECTION PATTERN FOCUSES ON THE AREA. THIS
PATTERN SHOULD MAINTAIN THE POTENTIAL FOR SOME LIMITED SNOWS ACROSS
THE ENTIRE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C OVER THE COURSE OF THE WEEKEND SHOULD GENERATE SOME
LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR WILL BE ADVECTION
OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR NOW...WILL KEEP
LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER GUIDANCE MAY SUGGEST
BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER TO THE TUG HILL.
GFS/ECMWF SUGGESTING POTENTIAL FOR BACKING FLOW LATE SUNDAY AND
MONDAY WHICH WOULD BRING ANY LAKE SNOWS NORTHWARD...POTENTIALLY
IMPACTING THE BUFFALO/WATERTOWN AREAS. STAY TUNED.
MORE SEASONABLE TEMPERATURES SHOULD BE THE CASE IN THE LESS
AMPLIFIED FLOW AT THE START OF THE PERIOD...BUT SHOULD DROP WELL
BELOW NORMAL LEVELS AS THE REINFORCING SHOT OF ARCTIC AIR WORKS INTO
THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A VERY WEAK AREA OF LOW PRESSURE OVER LAKE ONTARIO WILL DRIFT EAST
OVERNIGHT...WITH COLD AIR IN ITS WAKE CROSSING LAKES ERIE AND
ONTARIO. THIS COLD CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS
THE MAJORITY OF WESTERN NEW YORK OVERNIGHT THROUGH MUCH OF TUESDAY
WITH CIGS RANGING FROM 2500 TO 3500 FT AND VSBYS OCCASIONALLY
FALLING TO BETWEEN 3 AND 5 SM IN LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE TUESDAY AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TUESDAY NIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH
NEAR TERM...HITCHCOCK/RSH
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK/RSH
MARINE...TMA
000
FXUS61 KBUF 200044
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
744 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR TORONTO WILL CONTINUE TO WEAKEN AND MOVE
NORTHEAST. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF THIS
SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING TREND IS
THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE END OF THE
WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE REMNANTS OF A WEAK SURFACE LOW OVER SOUTHERN ONTARIO THIS
AFTERNOON HAS MADE ITS WAY TO THE CENTER OF LAKE ONTARIO AS OF 00Z
(AS PER THE WV IMAGERY). AS A RESULT OF THIS EASTWARD MOVEMENT...
THE ASSOCIATED SNOW BAND THAT WAS FOUND OVER LAKE ERIE AT THE START
OF THE EVENING RUSH HOUR HAS `COME OFF` THE LAKE AND HAS WEAKENED
ACCORDINGLY.
THE REMAINING SNOW HAS BECOME CONCENTRATED OVER CHAUTAUQUA
COUNTY...WHERE WHAT LITTLE LAKE ENHANCEMENT IS HELPING TO PRODUCE
MODERATE TO HEAVY SNOWS OVER THE NORTHERN PORTIONS OF CHAUTAUQUA
AND CATTARAUGUS COUNTIES. THIS ACTIVITY SHOULD CONTINUE TO PRESS TO
THE SOUTH THROUGH MIDNIGHT AS THE LOW LEVEL FLOW WILL VEER TO THE
NORTHWEST. THE FLOW WILL THEN BECOME ORTHOGONAL TO THE CHAUTAUQUA
RIDGE...WITH THE LAKE SNOW BECOMING ANCHORED/CONCENTRATED OVER THAT
AREA AND SLIGHTLY FURTHER INLAND. THE LOCALLY RUN 6KM MESOSCALE
MODELS SUGGEST THIS POSSIBILITY AS WELL...SO WE WILL HAVE TO WATCH
THIS AREA FOR POSSIBLE LAKE EFFECT SNOW ADVISORY AS THE EVENING
PROGRESSES.
ANOTHER AREA OF SNOW IS FOUND STRETCHING FROM THE OPEN WATERS OF
WESTERN LAKE ONTARIO TO THE ST CATHERINES AREA. THIS AREA OF SNOW IS
EXPECTED TO SAG TO THE SOUTH AND WILL COME ASHORE AND IMPACT ALL OF
THE LAKE SHORE COUNTIES FROM THE NIAGARA RIVER TO OSWEGO DURING THE
COURSE OF THE NIGHT. LIKELY POPS ARE CURRENTLY IN PLAY FOR THIS
SCENARIO...BUT MAY HAVE TO BOOST TO CATEGORICAL AS THE NIGHT MATURES.
ON TUESDAY MORNING THE BOUNDARY LAYER FLOW WILL BECOME RE-ALIGNED ON
A 340 VECTOR. DECENT INSTABILITY REMAINS IN PLACE...AND SHOULD BE
FAVORABLE FOR PLENTY OF LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF
WESTERN AND CENTRAL NEW YORK TO THE SOUTH AND SOUTHEAST OF LAKE
ONTARIO. OUR LOCAL 6KM WRF SUPPORTS THIS SCENARIO AS WELL. UPSLOPE
FLOW ACROSS THE SOUTHERN TIER AND FINGER LAKES SHOULD SUPPORT THE
LAKE EFFECT SNOW SHOWERS WELL INLAND. WILL GO WITH LIKELY POPS AGAIN
ACROSS MUCH OF THE AREA DURING THE MORNING HOURS. BY AFTERNOON THE
FLOW BACKS MORE TO 310-320 DEGREES...WHICH WILL FOCUS ANY REMAINING
ACTIVITY TO THE SOUTHEAST OF THE LAKE IN AREAS BETWEEN ROCHESTER AND
OSWEGO.
AS FAR AS AMOUNTS GO...EXPECT 1 TO 3 INCHES ALONG THE SOUTH
SHORE OF LAKE ONTARIO TONIGHT...WITH ANOTHER 1 TO 2 INCHES TUESDAY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
MINOR LAKE SNOWS SHOULD BE ONGOING AT THE START OF THE PERIOD AS 850
MB TEMPERATURES BETWEEN MINUS 12C AND MINUS 14C CONTINUE ON A
NORTHWEST FLOW. THE SURFACE RIDGE IS EXPECTED TO CREST OVER THE
REGION LATE TUESDAY NIGHT...BUT THE 850 MB RIDGE REMAINS JUST TO THE
WEST THROUGH AT LEAST WEDNESDAY MORNING...THEREFORE ANY LAKE SNOWS
SHOULD CONTINUE INTO THE FIRST HALF OF WEDNESDAY SOUTHEAST OF THE
LAKES. SOME WEAK ISENTROPIC UPGLIDE WILL DEVELOP ACROSS THE AREA AS
THE HIGH SHIFTS EAST OF THE AREA LATER WEDNESDAY AND WEDNESDAY NIGHT
AS A WEAK WARM AIR ADVECTION PATTERN FOCUSES ON THE AREA. THIS
PATTERN SHOULD MAINTAIN THE POTENTIAL FOR SOME LIMITED SNOWS ACROSS
THE ENTIRE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C OVER THE COURSE OF THE WEEKEND SHOULD GENERATE SOME
LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR WILL BE ADVECTION
OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR NOW...WILL KEEP
LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER GUIDANCE MAY SUGGEST
BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER TO THE TUG HILL.
GFS/ECMWF SUGGESTING POTENTIAL FOR BACKING FLOW LATE SUNDAY AND
MONDAY WHICH WOULD BRING ANY LAKE SNOWS NORTHWARD...POTENTIALLY
IMPACTING THE BUFFALO/WATERTOWN AREAS. STAY TUNED.
MORE SEASONABLE TEMPERATURES SHOULD BE THE CASE IN THE LESS
AMPLIFIED FLOW AT THE START OF THE PERIOD...BUT SHOULD DROP WELL
BELOW NORMAL LEVELS AS THE REINFORCING SHOT OF ARCTIC AIR WORKS INTO
THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A VERY WEAK AREA OF LOW PRESSURE OVER LAKE ONTARIO WILL DRIFT EAST
OVERNIGHT...WITH COLD AIR IN ITS WAKE CROSSING LAKES ERIE AND
ONTARIO. THIS COLD CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS
THE MAJORITY OF WESTERN NEW YORK OVERNIGHT THROUGH MUCH OF TUESDAY
WITH CIGS RANGING FROM 2500 TO 3500 FT AND VSBYS OCCASIONALLY
FALLING TO BETWEEN 3 AND 5 SM IN LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE TUESDAY AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TUESDAY NIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ007.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...HITCHCOCK/RSH
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK/RSH
MARINE...TMA
000
FXUS61 KBUF 200032
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
732 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR TORONTO WILL CONTINUE TO WEAKEN AND MOVE
NORTHEAST. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF THIS
SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING TREND IS
THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE END OF THE
WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE REMNANTS OF A WEAK SURFACE LOW OVER SOUTHERN ONTARIO THIS
AFTERNOON HAS MADE ITS WAY TO THE CENTER OF LAKE ONTARIO AS OF 00Z
(AS PER THE WV IMAGERY). AS A RESULT OF THIS EASTWARD MOCVEMENT...
THE ASSOCIATED SNOW BAND THAT WAS FOUND OVER LAKE ERIE AT THE START
OF THE EVENING RUSH HOUR HAS `COME OFF` THE LAKE AND HAS WEAKENED
ACCORDINGLY.
THE REMAINING SNOW HAS BECOME CONCENTRATED OVER CHAUTAUQUA
COUNTY...WHERE WHAT LITTLE LAKE ENHANCEMENT IS HELPING TO PRODUCE
MOCDERATE TO HEAVY SNOWS OVER THE NORTHERN PORTIONS OF CHAUTAUQUA
AND CATTARAUGUS COUNTIES. THIS ACTIVITY SHOULD CONTINUE TO PRESS TO
THE SOUTH THROUGH MIDNIGHT AS THE LOW LEVEL FLOW WILL VEER TO THE
NORTHWEST. THE FLOW WILL THEN BECOME ORTHOGONAL TO THE CHAUTAUQUA
RIDGE...WITH THE LAKE SNOW BECOMING ANCHORED/CONCENTRATED OVER THAT
AREA AND SLIGHTLY FURTHER INLAND. THE LOCALLY RUN 6KM MESOSCALE
MODELS SUGGEST THIS POSSIBILITY AS WELL...SO WE WILL HAVE TO WATCH
THIS AREA FOR POSSIBLE LAKE EFFECT SNOW ADVISORY AS THE EVENING
PROGRESSES.
ANOTHER AREA OF SNOW IS FOUND STRETCHING FROM THE OPEN WATERS OF
WESTERN LAKE ONTARIO TO THE ST CATHERINES AREA. THIS AREA OF SNOW IS
EXPECTED TO SAG TO THE SOUTH AND WILL COME ASHORE AND IMPACT ALL OF
THE COUNTIES FROM THE NIAGARA RIVER TO OSWEGO DURING THE COURSE OF
THE NIGHT. LIKELY POPS ARE CURRENTLY IN PLAY FOR THIS SCENARIO...
BUT MAY HAVE TO BOOST TO CATEGORICAL AS THE NIGHT MATURES.
ON TUESDAY MORNING THE BOUNDARY LAYER FLOW WILL BECOME RE-ALIGNED ON
A 340 VECTOR. DECENT INSTABILITY REMAINS IN PLACE...AND SHOULD BE
FAVORABLE FOR PLENTY OF LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF
WESTERN AND CENTRAL NEW YORK TO THE SOUTH AND SOUTHEAST OF LAKE
ONTARIO. OUR LOCAL 6KM WRF SUPPORTS THIS SCENARIO AS WELL. UPSLOPE
FLOW ACROSS THE SOUTHERN TIER AND FINGER LAKES SHOULD SUPPORT THE
LAKE EFFECT SNOW SHOWERS WELL INLAND. WILL GO WITH LIKELY POPS AGAIN
ACROSS MUCH OF THE AREA DURING THE MORNING HOURS. BY AFTERNOON THE
FLOW BACKS MORE TO 310-320 DEGREES...WHICH WILL FOCUS ANY REMAINING
ACTIVITY TO THE SOUTHEAST OF THE LAKE IN AREAS BETWEEN ROCHESTER AND
OSWEGO.
AS FAR AS AMOUNTS GO...EXPECT 1 TO 3 INCHES ALONG THE SOUTH
SHORE OF LAKE ONTARIO TONIGHT...WITH ANOTHER 1 TO 2 INCHES TUESDAY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
MINOR LAKE SNOWS SHOULD BE ONGOING AT THE START OF THE PERIOD AS 850
MB TEMPERATURES BETWEEN MINUS 12C AND MINUS 14C CONTINUE ON A
NORTHWEST FLOW. THE SURFACE RIDGE IS EXPECTED TO CREST OVER THE
REGION LATE TUESDAY NIGHT...BUT THE 850 MB RIDGE REMAINS JUST TO THE
WEST THROUGH AT LEAST WEDNESDAY MORNING...THEREFORE ANY LAKE SNOWS
SHOULD CONTINUE INTO THE FIRST HALF OF WEDNESDAY SOUTHEAST OF THE
LAKES. SOME WEAK ISENTROPIC UPGLIDE WILL DEVELOP ACROSS THE AREA AS
THE HIGH SHIFTS EAST OF THE AREA LATER WEDNESDAY AND WEDNESDAY NIGHT
AS A WEAK WARM AIR ADVECTION PATTERN FOCUSES ON THE AREA. THIS
PATTERN SHOULD MAINTAIN THE POTENTIAL FOR SOME LIMITED SNOWS ACROSS
THE ENTIRE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C OVER THE COURSE OF THE WEEKEND SHOULD GENERATE SOME
LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR WILL BE ADVECTION
OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR NOW...WILL KEEP
LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER GUIDANCE MAY SUGGEST
BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER TO THE TUG HILL.
GFS/ECMWF SUGGESTING POTENTIAL FOR BACKING FLOW LATE SUNDAY AND
MONDAY WHICH WOULD BRING ANY LAKE SNOWS NORTHWARD...POTENTIALLY
IMPACTING THE BUFFALO/WATERTOWN AREAS. STAY TUNED.
MORE SEASONABLE TEMPERATURES SHOULD BE THE CASE IN THE LESS
AMPLIFIED FLOW AT THE START OF THE PERIOD...BUT SHOULD DROP WELL
BELOW NORMAL LEVELS AS THE REINFORCING SHOT OF ARCTIC AIR WORKS INTO
THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A VERY WEAK AREA OF LOW PRESSURE OVER LAKE ONTARIO WILL DRIFT EAST
OVERNIGHT...WITH COLD AIR IN ITS WAKE CROSSING LAKES ERIE AND
ONTARIO. THIS COLD CYCLONIC FLOW WILL PRODUCE MVFR CONDITIONS ACROSS
THE MAJORITY OF WESTERN NEW YORK OVERNIGHT THROUGH MUCH OF TUESDAY
WITH CIGS RANGING FROM 2500 TO 3500 FT AND VSBYS OCCASIONALLY
FALLING TO BETWEEN 3 AND 5 SM IN LIGHT LAKE EFFECT SNOW.
CIGS AND VSBYS MAY BE LOWER AT TIMES AT KJHW AND KROC DUE TO THEIR
PROXIMITY TO THEIR RESPECTIVE LAKES (ERIE AND ONTARIO).
CONDITIONS WILL TEND TO IMPROVE TUESDAY AFTERNOON SO THAT MOST SITES
WILL BECOME VFR.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TUESDAY NIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ007.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...HITCHCOCK/RSH
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK/RSH
MARINE...TMA
000
FXUS61 KBUF 192009
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
309 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR TORONTO WILL CONTINUE TO WEAKEN AND MOVE
NORTHEAST. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF THIS
SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING TREND IS
THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE END OF THE
WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
MOISTURE CHANNEL IMAGERY SHOWS A WEAK VERTICALLY STACKED LOW OVER
SOUTHERN ONTARIO PROVINCE THIS AFTERNOON. KBUF RADAR IMAGERY SHOWS
THE CENTER OF THE CIRCULATION APPROACHING CYSN AT 20Z. SHORT TERM
MODEL GUIDANCE TAKES THIS FEATURE EAST ACROSS THE REGION THIS
EVENING...WITH A TRACK GENERALLY ALONG THE THRUWAY. BOTH THE NAM/GFS
SHOW THE 700MB CIRCULATION NEAR KSYR BY 06Z...THEN OPENING UP INTO
THE LOWER SAINT LAWRENCE VALLEY BY 12Z TUESDAY. SCATTERED LIGHT SNOW
SHOWERS WILL DEVELOP FROM WEST TO EAST ACROSS THE AREA LATE THIS
AFTERNOON AND EVENING JUST AHEAD OF THIS FEATURE. OUTSIDE OF LAKE
EFFECT AREAS AMOUNTS WILL BE LIGHT...WITH AN INCH OR LESS
ACCUMULATION.
NOTHING IS EVER EASY IN THE LEE OF THE GREAT LAKES HOWEVER...AND
THERE WILL CONTINUE TO BE VERY DIFFICULT TO FORECAST LAKE
ENHANCEMENT GOING ON WITHIN A WEAK FLOW REGIME. THERMODYNAMICS ARE
DECENT OVERNIGHT WITH 850MB TEMPS OF AROUND -15C CONTRIBUTING TO
LAKE INDUCED EQUILIBRIUM LEVELS OF 7-8 THOUSAND FEET. THE FLOW WILL
BE VERY WEAK AND DISORGANIZED HOWEVER WITH PLENTY OF SHEAR WITHIN
THE CLOUD BEARING LAYER. THIS WILL MAKE PLACEMENT AND TIMING OF LAKE
EFFECT/ENHANCED SNOW PARTICULARLY DIFFICULT.
OFF LAKE ONTARIO...A PERSISTENT BAND OF LAKE EFFECT SNOW REMAINS
ACROSS CENTRAL JEFFERSON COUNTY THIS AFTERNOON. MESOSCALE MODEL
GUIDANCE IS COMPLETELY MISSING THIS...WHICH IS OFTEN THE CASE IN
THESE WEAK/MARGINAL ENVIRONMENTS. EXPECT THIS ACTIVITY TO PERSIST
THROUGH ABOUT 00Z OR SO...WITH THE MOST CONCENTRATED ACTIVITY FROM
STONY POINT THROUGH WATERTOWN AND DEFERIET. ANOTHER 2 TO 4 INCHES OF
ACCUMULATION IS POSSIBLE IN THESE AREAS AFTER 3PM. WILL MAINTAIN THE
ADVISORY FOR JEFF COUNTY THROUGH THIS EVENING...BUT WILL DROP LEWIS
AS THE SHALLOW SOUTHWEST FLOW SHOULD CONTINUE TO STEER THE BAND
NORTHWEST OF THAT COUNTY. THIS EVENING THE BOUNDARY LAYER FLOW WILL
CONTINUE TO DIMINISH WITH THE APPROACH OF THE WEAK SURFACE LOW. THIS
SHOULD ALLOW THE LAKE BAND TO CONTRACT BACK TO THE LAKESHORE AND
EVENTUALLY OFFSHORE...ENDING THE SNOW IN JEFFERSON COUNTY.
OFF LAKE ERIE...EXPECT A BAND OF LAKE ENHANCED SNOW...NOW DEVELOPING
ON KBUF RADAR IMAGERY OVER EASTERN LAKE ERIE TO EXPAND ACROSS THE
BUF METRO AREA DURING THE MID TO LATE AFTERNOON. THIS BAND IS BEING
SUPPORTED BY LARGE SCALE FORCING FOR ASCENT AND LOW LEVEL
CONVERGENCE JUST AHEAD OF THE WEAK SURFACE LOW. THIS BAND WILL THEN
PUSH INTO SKI COUNTRY THIS EVENING AND TEND TO BREAK APART. MAY SEE
A QUICK 1-2 INCHES ACROSS THE BUF METRO AREA LATE THIS AFTERNOON...
THEN SIMILAR AMOUNTS ACROSS SKI COUNTRY THIS EVENING. OVERNIGHT INTO
TUESDAY THE SHORT FETCH ON NORTHWEST FLOW COMBINED WITH EXTENSIVE
ICE COVER ON EASTERN LAKE ERIE WILL REALLY LIMIT ACTIVITY. MAY SEE
AN INCH OR TWO IN THE UPSLOPE AREAS OF THE CHAUTAUQUA RIDGE...BUT
THESE AREAS MAY END UP SEEING MORE FROM ONTARIO THAN ERIE GIVEN THE
340 FLOW.
BACK TO LAKE ONTARIO...AFTER THE SURFACE LOW PASSES BY...EXPECT A
REMNANT CONVERGENCE BAND WHICH HAS BEEN MEANDERING IN THE MIDDLE OF
THE LAKE TODAY...TO PUSH SOUTH AND ONSHORE ALONG MUCH OF THE SOUTH
SHORE OF LAKE ONTARIO. THIS IS HINTED AT TO SOME EXTENT BY THE
LATEST 12Z NCEP NAM. THIS SHOULD BRING ANOTHER PERIOD OF SNOW
SHOWERS TO THE SOUTH SHORE OF LAKE ONTARIO OVERNIGHT FROM NIAGARA TO
OSWEGO COUNTIES. AS THE FLOW COMES AROUND TO THE NORTHWEST...THIS
BAND MAY BE SHOVED ALL THE WAY SOUTH ACROSS MUCH OF THE CWA
OVERNIGHT...AND HAVE GONE WITH LIKELY POPS IN MOST AREAS WEST OF
OSWEGO COUNTY OVERNIGHT TO ACCOUNT FOR THIS POTENTIAL. TUESDAY
MORNING THE BOUNDARY LAYER FLOW WILL BECOME RE-ALIGNED ON A 340
VECTOR. DECENT INSTABILITY REMAINS IN PLACE...AND SHOULD BE
FAVORABLE FOR PLENTY OF LIGHT SNOW SHOWER ACTIVITY ACROSS MUCH OF
WESTERN AND CENTRAL NEW YORK TO THE SOUTH AND SOUTHEAST OF LAKE
ONTARIO. OUR LOCAL 6KM WRF SUPPORTS THIS SCENARIO AS WELL. UPSLOPE
FLOW ACROSS THE SOUTHERN TIER AND FINGER LAKES SHOULD SUPPORT THE
LAKE EFFECT SNOW SHOWERS WELL INLAND. WILL GO WITH LIKELY POPS AGAIN
ACROSS MUCH OF THE AREA DURING THE MORNING HOURS. BY AFTERNOON THE
FLOW BACKS MORE TO 310-320 DEGREES...WHICH WILL FOCUS ANY REMAINING
ACTIVITY TO THE SOUTHEAST OF THE LAKE IN AREAS BETWEEN ROCHESTER AND
OSWEGO. AS FAR AS AMOUNTS GO...EXPECT 1 TO 3 INCHES ALONG THE SOUTH
SHORE OF LAKE ONTARIO TONIGHT...WITH ANOTHER 1 TO 2 INCHES TUESDAY.
NOT ENOUGH TO JUSTIFY ANY HEADLINES ATTM BUT LATER SHIFTS CAN
MONITOR FOR AREAS OF BETTER ORGANIZATION.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
MINOR LAKE SNOWS SHOULD BE ONGOING AT THE START OF THE PERIOD AS 850
MB TEMPERATURES BETWEEN MINUS 12C AND MINUS 14C CONTINUE ON A
NORTHWEST FLOW. THE SURFACE RIDGE IS EXPECTED TO CREST OVER THE
REGION LATE TUESDAY NIGHT...BUT THE 850 MB RIDGE REMAINS JUST TO THE
WEST THROUGH AT LEAST WEDNESDAY MORNING...THEREFORE ANY LAKE SNOWS
SHOULD CONTINUE INTO THE FIRST HALF OF WEDNESDAY SOUTHEAST OF THE
LAKES. SOME WEAK ISENTROPIC UPGLIDE WILL DEVELOP ACROSS THE AREA AS
THE HIGH SHIFTS EAST OF THE AREA LATER WEDNESDAY AND WEDNESDAY NIGHT
AS A WEAK WARM AIR ADVECTION PATTERN FOCUSES ON THE AREA. THIS
PATTERN SHOULD MAINTAIN THE POTENTIAL FOR SOME LIMITED SNOWS ACROSS
THE ENTIRE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LATEST MEDIUM RANGE MODELS CONTINUING TO SUGGEST THE RETREAT...AT
LEAST TEMPORARILY OF THE DEEP EASTERN CONUS TROUGH WITH A MUCH LESS
AMPLIFIED FLOW DEVELOPING DURING THE THURSDAY AND FRIDAY TIME
FRAME...BEFORE THE EASTERN TROUGH BECOMES RE-ESTABLISHED OVER THE
WEEKEND AND INTO EARLY NEXT WEEK GIVING THE AREA ANOTHER SHOT OF
FRESH ARCTIC AIR.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR THE END OF
THE WEEK AND INTO EARLY NEXT WEEK...WE WILL MAINTAIN THE GENERAL LOW
CHANCE PROBABILITIES FOR THE THURSDAY AND FRIDAY TIME FRAME AS A
WEAK CLIPPER SYSTEM WORKS ACROSS THE GREAT LAKES. AT THIS POINT...
THE PROGRESSIVE SYSTEM WILL HAVE LIMITED MOISTURE AND THE ASSOCIATED
WARM AIR ADVECTION PATTERN LOOKS RATHER WEAK...WHICH SHOULD LIMIT
POTENTIAL SNOW ACCUMULATIONS WITH THIS SYSTEM. THE CLIPPER WILL MOVE
EAST OF THE AREA BY SATURDAY WITH A FRESH SUPPLY OF ARCTIC AIR
BUILDING ACROSS THE AREA BEHIND IT. 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C OVER THE COURSE OF THE WEEKEND SHOULD GENERATE SOME
LAKE SNOWS SOUTHEAST OF THE LAKES. LIMITING FACTOR WILL BE ADVECTION
OF DRIER AIR INTO THE AREA AT THE SAME TIME. FOR NOW...WILL KEEP
LAKE POTENTIAL IN CHANCE RANGE...ALTHOUGH LATER GUIDANCE MAY SUGGEST
BETTER CHANCES ESPECIALLY FROM ROCHESTER OVER TO THE TUG HILL.
GFS/ECMWF SUGGESTING POTENTIAL FOR BACKING FLOW LATE SUNDAY AND
MONDAY WHICH WOULD BRING ANY LAKE SNOWS NORTHWARD...POTENTIALLY
IMPACTING THE BUFFALO/WATERTOWN AREAS. STAY TUNED.
MORE SEASONABLE TEMPERATURES SHOULD BE THE CASE IN THE LESS
AMPLIFIED FLOW AT THE START OF THE PERIOD...BUT SHOULD DROP WELL
BELOW NORMAL LEVELS AS THE REINFORCING SHOT OF ARCTIC AIR WORKS INTO
THE AREA OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
A WEAK AREA OF LOW PRESSURE OVER SOUTHERN ONTARIO PROVINCE WILL MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND THIS EVENING. THIS
WILL BRING A PERIOD OF SNOW SHOWERS...ENHANCED BY A SOUTHWEST FLOW
OFF LAKE ERIE...TO ALL OF THE WESTERN TAF SITES. EXPECT MVFR/IFR
VSBY IN SNOW SHOWERS STARTING EARLY AFTERNOON AT KBUF-KIAG-KJHW
SPREADING EAST TO KROC BY MID TO LATE AFTERNOON. THIS ACTIVITY WILL
CONTINUE THROUGH EARLY EVENING BEFORE DIMINISHING AS THE MID LEVEL
TROUGH AXIS PUSHES EAST OF THE AREA. OVERNIGHT...A BAND OF LAKE
EFFECT SNOW CURRENTLY MEANDERING OVER THE MIDDLE OF LAKE ONTARIO
WILL BE FORCED SOUTHWARD AS THE FLOW BECOMES MORE NORTHWEST BEHIND
THE DEPARTING SYSTEM. THIS MAY BRING ANOTHER PERIOD OF MVFR/IFR VSBY
IN SNOW SHOWERS TO MANY OF THE TAF SITES BETWEEN ABOUT 04Z-09Z. AS
THE FLOW BECOMES NNW TUESDAY MORNING...THERE MAY BE RATHER
WIDESPREAD LIGHT LAKE EFFECT SNOW SHOWERS OFF LAKE ONTARIO ACROSS
MUCH OF WESTERN NY...AIDED BY UPSLOPE FLOW. THIS WILL BRING PERIODS
OF MVFR/IFR VSBY THROUGH MIDDAY TUESDAY.
EAST OF LAKE ONTARIO...A BAND OF HEAVY LAKE EFFECT SNOW CONTINUES
JUST SOUTH OF KART AT 1730Z. EXPECT THE CORE OF THIS BAND TO STAY
JUST SOUTH OF THE TERMINAL...BUT KART WILL CONTINUE TO BE BRUSHED BY
THE EDGE OF THE BAND WITH OCCASIONAL MVFR/IFR VSBY THROUGH ABOUT
00Z. AFTER THAT...THE FLOW WEAKENS EVEN MORE AND SHOULD ALLOW THE
BAND TO CONTRACT BACK OVER THE LAKE AND END THE SNOW AT KART.
ANOTHER BRIEF PERIOD OF LIGHT SNOW MAY COME INTO KART BETWEEN
06Z-12Z WITH THE PASSAGE OF A WEAK LOW LEVEL TROUGH.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH TUESDAY NIGHT...AND THIS WILL RESULT IN WINDS
AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA. THE GRADIENT ON THE
LAKES WILL PICK UP WEDNESDAY WITH THE POTENTIAL FOR SMALL CRAFT
CONDITIONS DEVELOPING ON LAKE ONTARIO WEDNESDAY AND THURSDAY.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ007.
MARINE...NONE.
&&
$$
SYNOPSIS...TMA
NEAR TERM...HITCHCOCK
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...HITCHCOCK
MARINE...TMA
000
FXUS61 KBUF 191747
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1247 PM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR LAKE ONTARIO WILL CONTINUE TO WEAKEN AND
MOVE NORTHEAST TODAY. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF
THIS SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION
THROUGH TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEAK VERTICALLY STACKED LOW OVER SOUTHERN ONTARIO PROVINCE THIS
MORNING WILL SLOWLY MOVE EAST AND CROSS THE REGION THIS AFTERNOON
AND THIS EVENING. WEAK LARGE SCALE LIFT ASSOCIATED WITH THE PASSAGE
OF THE MID LEVEL TROUGH AND WEAK LOW LEVEL CONVERGENCE NEAR THE
SURFACE LOW WILL ACT ON A DEEP LOW LEVEL MOISTURE FIELD TO BRING
SCATTERED SNOW SHOWERS TO MUCH OF THE AREA LATER TODAY THROUGH THIS
EVENING. OUTSIDE OF LAKE EFFECT AREAS AMOUNTS WILL BE LIGHT. THE
WEAK/DISORGANIZED FLOW WILL MAKE THE LAKE EFFECT FORECAST EXTREMELY
CHALLENGING AND LOW CONFIDENCE.
OFF LAKE ONTARIO...AN AREA OF LAKE EFFECT/UPSLOPE SNOW CONTINUES
EAST OF LAKE ONTARIO EARLY THIS AFTERNOON. A HEALTHY BAND REMAINS
OVER A SMALL PART OF SOUTHERN JEFFERSON COUNTY FROM NEAR STONY POINT
TO ADAMS CENTER. THIS WILL CONTINUE TO PRODUCE SNOWFALL RATES OF 1
TO 2 INCHES PER HOUR THROUGH MID AFTERNOON. THE BAND HAS BEEN
CREEPING VERY SLOWLY NORTH...AND EXPECT THIS TREND TO CONTINUE. THE
BAND SHOULD TEND TO WEAKEN AS IT MOVES INTO WATERTOWN. THE FLOW
WITHIN THE 1-3 THOUSAND FOOT LAYER WILL CONTINUE TO WEAKEN THIS
AFTERNOON WITH THE APPROACH OF THE WEAK LOW OVER SOUTHERN ONTARIO.
THIS SHOULD FORCE THE BAND TO CONTRACT BACK TO THE WEST AND FORCE
THE STEADIER SNOW BACK OVER THE LAKE.
OFF LAKE ERIE...FLOW IS SSW THIS MORNING...WITH WEAK LAKE ENHANCED
SNOW UP ACROSS THE NIAGARA PENINSULA OF SOUTHERN ONTARIO. LAKE ERIE
HAS DEVELOPED SIGNIFICANT ICE COVER OVER THE PAST WEEK...WHICH WILL
COMPLICATE THE FORECAST. RECENT STUDIES SUCH AS CORDEIRA AND LAIRD
2008 AND GERBUSH...KRISTOVICH...AND LAIRD 2008 HAVE SUGGESTED THAT
70 PERCENT ICE CONCENTRATION IS NECESSARY BEFORE LATENT AND SENSIBLE
HEAT FLUX IS SIGNIFICANTLY DIMINISHED. EVEN WITH TOTAL ICE
COVER...THERE IS STILL SENSIBLE HEAT FLUX THROUGH THE
ICE...ESPECIALLY THIN ICE COVER. THUS...WHILE LAKE SNOW POTENTIAL IS
DIMINISHED SOMEWHAT... THE POTENTIAL IS STILL THERE FOR SOME
ACTIVITY. THE FLOW OFF LAKE ERIE WILL ALSO BE WEAK AND
DISORGANIZED...MAKING FOR A DIFFICULT FORECAST. FEEL THE BEST
POTENTIAL WILL BE LATE THIS AFTERNOON AND EARLY EVENING AS THE WIND
SHIFT ASSOCIATED WITH THE MID LEVEL TROUGH CROSSES THE LAKE. THIS
MAY ENHANCE LOW LEVEL CONVERGENCE ENOUGH TO PRODUCE AN AREA OF LAKE
ENHANCEMENT ACROSS THE BUF METRO AREA... SINKING SOUTH INTO SKI
COUNTRY THIS EVENING. FOR NOW WILL JUST KEEP LIKELY TO CAT POPS
GOING WITH AN INCH OR SO...AND CONTINUE TO MONITOR FOR THE AFTERNOON.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
A HIGH AMPLITUDE UPPER TROUGH WILL CONTINUE TO BE ENTRENCHED
OVER THE EASTERN HALF OF THE CONTINENT AT THE BEGINNING OF THIS
PERIOD WITH A SURFACE LOW POSITIONED WELL OFF THE MID ATLANTIC COAST
AND A RIDGE OF HIGH PRESSURE EXTENDING FROM TEXAS TO THE UPPER GREAT
LAKES. THE RESULT ACROSS OUR REGION WILL BE A NORTHWEST FLOW OF COLD
AIR WITH 850 TEMPERATURES FORECAST TO BE IN THE MINUS 14C TO MINUS
16C RANGE. ALTHOUGH THERE WILL BE SOME WARMING ABOVE THE 850 MB
LEVEL THE LOW LEVEL COLD AIR REMAINS DEEP AND MOIST ENOUGH FOR MINOR
LAKE EFFECT SNOW SHOWERS. THE HIGHEST POPS WILL BE OVER THE COUNTIES
JUST SOUTH OF LAKE ONTARIO BUT WE WILL MENTION AT LEAST SCATTERED
SNOW SHOWERS EVERYWHERE. AT THIS TIME WE DO NOT EXPECTED ANY
IMPORTANT ACCUMULATIONS. THE SURFACE RIDGE IS EXPECTED TO CREST OVER
THE REGION LATE TUESDAY NIGHT BUT THE 850 MB RIDGE REMAINS JUST TO
THE WEST EVEN BY 12Z WEDNESDAY SO SCATTERED SNOW SHOWERS ARE
EXPECTED SOUTHEAST OF BOTH LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED BY ANOTHER
SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER TROUGHING OVER THE
EASTERN THIRD OF THE CONTINENT BRIEFLY GETS REINFORCED.
THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL MIDWINTER
TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK OF THE
MONTH AS THE FLOW ALOFT TRENDS TO MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WARMING ALOFT AND A WEAK SURFACE PATTERN
SHOULD PROVIDE THE AREA WITH PRETTY MUCH A BENIGN WEATHER DAY ON
THURSDAY. THE LATEST ECMWF IS VERY CLOSE TO YESTERDAY/S RUN WHEREAS
THE GFS HAS HAD A LOT OF RUN TO RUN DIFFERENCES. WE WILL STAY WITH
THE ECMWF SOLUTION FOR FRIDAY THROUGH THE WEEKEND WITH A CLIPPER
SYSTEM CROSSING THE AREA FRIDAY. FOLLOWING THE PASSAGE OF THIS
LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR THE UPCOMING
WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
COLDER THAN MINUS 20C FOR THE WEEKEND...THERE WILL DEFINITELY BE
SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A WEAK AREA OF LOW PRESSURE OVER SOUTHERN ONTARIO PROVINCE WILL MOVE
EAST ACROSS THE AREA LATER THIS AFTERNOON AND THIS EVENING. THIS
WILL BRING A PERIOD OF SNOW SHOWERS...ENHANCED BY A SOUTHWEST FLOW
OFF LAKE ERIE...TO ALL OF THE WESTERN TAF SITES. EXPECT MVFR/IFR
VSBY IN SNOW SHOWERS STARTING EARLY AFTERNOON AT KBUF-KIAG-KJHW
SPREADING EAST TO KROC BY MID TO LATE AFTERNOON. THIS ACTIVITY WILL
CONTINUE THROUGH EARLY EVENING BEFORE DIMINISHING AS THE MID LEVEL
TROUGH AXIS PUSHES EAST OF THE AREA. OVERNIGHT...A BAND OF LAKE
EFFECT SNOW CURRENTLY MEANDERING OVER THE MIDDLE OF LAKE ONTARIO
WILL BE FORCED SOUTHWARD AS THE FLOW BECOMES MORE NORTHWEST BEHIND
THE DEPARTING SYSTEM. THIS MAY BRING ANOTHER PERIOD OF MVFR/IFR VSBY
IN SNOW SHOWERS TO MANY OF THE TAF SITES BETWEEN ABOUT 04Z-09Z. AS
THE FLOW BECOMES NNW TUESDAY MORNING...THERE MAY BE RATHER
WIDESPREAD LIGHT LAKE EFFECT SNOW SHOWERS OFF LAKE ONTARIO ACROSS
MUCH OF WESTERN NY...AIDED BY UPSLOPE FLOW. THIS WILL BRING PERIODS
OF MVFR/IFR VSBY THROUGH MIDDAY TUESDAY.
EAST OF LAKE ONTARIO...A BAND OF HEAVY LAKE EFFECT SNOW CONTINUES
JUST SOUTH OF KART AT 1730Z. EXPECT THE CORE OF THIS BAND TO STAY
JUST SOUTH OF THE TERMINAL...BUT KART WILL CONTINUE TO BE BRUSHED BY
THE EDGE OF THE BAND WITH OCCASIONAL MVFR/IFR VSBY THROUGH ABOUT
00Z. AFTER THAT...THE FLOW WEAKENS EVEN MORE AND SHOULD ALLOW THE
BAND TO CONTRACT BACK OVER THE LAKE AND END THE SNOW AT KART.
ANOTHER BRIEF PERIOD OF LIGHT SNOW MAY COME INTO KART BETWEEN
06Z-12Z WITH THE PASSAGE OF A WEAK LOW LEVEL TROUGH.
TUESDAY NIGHT...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST
OF THE LAKES.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
SATURDAY...VFR EXCEPT MVFR/IFR IN LAKE EFFECT SNOW SHOWERS EAST OF
THE LAKES.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN WINDS AND
WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ007-008.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...HITCHCOCK
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...HITCHCOCK
MARINE...JJR/SAGE
000
FXUS61 KBUF 191140
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
640 AM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR LAKE ONTARIO WILL CONTINUE TO WEAKEN AND
MOVE NORTHEAST TODAY. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF
THIS SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION
THROUGH TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE LOW OVER SOUTHERN ONTARIO BETWEEN LAKES ERIE AND HURON WILL
REMAIN IN PLACE OR MOVE SLIGHTLY TO THE EAST AS IT FILLS DURING THE
DAY. WILL KEEP UPPER CHANCE TO LOW LIKELY POPS ACROSS THE AREAS WAY
FROM LAKE INFLUENCES AS A VORT MAX IS FORECAST TO TRACK AROUND THE
UPPER LOW AND LIFT FROM THE OHIO VALLEY TO CENTRAL NY AND PA BETWEEN
12Z AND 21Z.
COLD 850MB TEMPS OF -16C ACROSS BOTH LAKES ERIE AND ONTARIO WILL
MAINTAIN SOME LIMITED LAKE EFFECT SNOW. THE LAKE INDUCED EQUILIBRIUM
LEVEL IS AROUND 7-9KFT THROUGH THE EVENING...LIMITED BY A MID LEVEL
ISOTHERMAL OR INVERSION LAYER EFFECTIVELY CAPPING THE VERTICAL
GROWTH OF LAKE EFFECT. THIS IS STILL DEEP ENOUGH AND COLD ENOUGH AND
BOUNDING THE DENDRITIC GROWTH ZONE...SO WE DO EXPECT A CONTINUATION
OF LIGHT TO MODERATE LAKE SNOWS...THE BIG QUESTION IS WHERE THE LAKE
SNOW BANDS WILL SET UP. THE PROXIMITY OF THE SURFACE LOW AND THE
SHEAR IN THE BOUNDARY LAYER WILL DEFINE THE PLACEMENT OF THE
SNOWBANDS.
OFF LAKE ERIE...ICE COVER OVER ALL BUT THE NORTHEAST QUARTER OF THE
LAKE WILL REDUCE THE EFFECTIVENESS OF LAKE EFFECT. SOUTH/SOUTHWEST
WINDS WILL INITIALLY ORIENT THE SNOW OVER NORTHERN ERIE AND NIAGARA
COUNTIES EARLY THIS MORNING...THEN A SHIFT TO SOUTHWEST/WESTERLY
WIND WILL FOCUS MULTIBANDED LAKE EFFECT TO THE SOUTHERN TIER AND
SOUTHERN ERIE COUNTY DURING THE AFTERNOON AND INTO TONIGHT.
FOR LAKE ONTARIO...THE MAJORITY OF THE LAKE IS ICE FREE AND CAPABLE
OF SUPPORTING MORE ROBUST LAKE SNOW...BUT WILL ALSO BE HELD IN CHECK
BY THE CAP ALOFT. EARLY TODAY...THE WINDS WILL DIRECT THE SNOW BAND
TO THE NORTHERN SHORE ON SOUTH TO SOUTHWEST SURFACE WINDS...BUT
FILLING OF THE SURFACE LOW AND THE REMAINING TROUGH OF LOW
PRESSURE OVER LAKE ONTARIO WILL SHIFT THE SNOW BAND TO THE
NORTHEASTERN SHORE OF THE LAKE THIS AFTERNOON...AND THEN MORE
NORTHERLY WINDS TONIGHT WILL FORCE THE SNOW TO THE SOUTH SHORE.
TEMPS TODAY WILL BE MAINLY IN THE LOWER TO MIDDLE 20S WITH SOME
TEENS OVER THE SOUTHERN TIER AND EAST OF LAKE ONTARIO. OVERNIGHT
LOWS WILL FALL BACK TO THE MID TEENS TO MIDDLE SINGLE NUMBERS AS
COLD AIR FOLLOWS THE NORTHWEST/NORTHERLY WINDS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
A HIGH AMPLITUDE UPPER TROUGH WILL CONTINUE TO BE ENTRENCHED
OVER THE EASTERN HALF OF THE CONTINENT AT THE BEGINNING OF THIS
PERIOD WITH A SURFACE LOW POSITIONED WELL OFF THE MID ATLANTIC COAST
AND A RIDGE OF HIGH PRESSURE EXTENDING FROM TEXAS TO THE UPPER GREAT
LAKES. THE RESULT ACROSS OUR REGION WILL BE A NORTHWEST FLOW OF COLD
AIR WITH 850 TEMPERATURES FORECAST TO BE IN THE MINUS 14C TO MINUS
16C RANGE. ALTHOUGH THERE WILL BE SOME WARMING ABOVE THE 850 MB
LEVEL THE LOW LEVEL COLD AIR REMAINS DEEP AND MOIST ENOUGH FOR MINOR
LAKE EFFECT SNOW SHOWERS. THE HIGHEST POPS WILL BE OVER THE COUNTIES
JUST SOUTH OF LAKE ONTARIO BUT WE WILL MENTION AT LEAST SCATTERED
SNOW SHOWERS EVERYWHERE. AT THIS TIME WE DO NOT EXPECTED ANY
IMPORTANT ACCUMULATIONS. THE SURFACE RIDGE IS EXPECTED TO CREST OVER
THE REGION LATE TUESDAY NIGHT BUT THE 850 MB RIDGE REMAINS JUST TO
THE WEST EVEN BY 12Z WEDNESDAY SO SCATTERED SNOW SHOWERS ARE
EXPECTED SOUTHEAST OF BOTH LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED BY ANOTHER
SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER TROUGHING OVER THE
EASTERN THIRD OF THE CONTINENT BRIEFLY GETS REINFORCED.
THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL MIDWINTER
TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK OF THE
MONTH AS THE FLOW ALOFT TRENDS TO MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WARMING ALOFT AND A WEAK SURFACE PATTERN
SHOULD PROVIDE THE AREA WITH PRETTY MUCH A BENIGN WEATHER DAY ON
THURSDAY. THE LATEST ECMWF IS VERY CLOSE TO YESTERDAY/S RUN WHEREAS
THE GFS HAS HAD A LOT OF RUN TO RUN DIFFERENCES. WE WILL STAY WITH
THE ECMWF SOLUTION FOR FRIDAY THROUGH THE WEEKEND WITH A CLIPPER
SYSTEM CROSSING THE AREA FRIDAY. FOLLOWING THE PASSAGE OF THIS
LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR THE UPCOMING
WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
COLDER THAN MINUS 20C FOR THE WEEKEND...THERE WILL DEFINITELY BE
SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A MOIST CYCLONIC FLOW BEHIND A WEAKENING OCCLUDED FRONT WILL
CONTINUE TO GENERATE SOME LIGHT SNOW...ACCOMPANIED BY OCCASIONAL
MVFR CIGS/VSBYS. THE SNOW WILL BE MORE STEADY NORTHEAST OF LAKE ERIE
WHERE THERE WILL BE AN ADDITIONAL INFLUX OF MOISTURE FROM THE LAKE.
THIS WILL ALLOW VSBYS TO LOWER TO IFR AT TIMES VCNTY KBUF/KIAG. THIS
BAND OF LAKE SNOW WILL SETTLE SOUTH TO AFFECT KJHW DURING THE LATE
AFTERNOON THROUGH TONIGHT. EXPECT A SIMILAR TREND EAST OF LAKE
ONTARIO AS LAKE SNOW OVER THE NORTHEAST CORNER OF THE LAKE AFFECTS
KART TODAY...THEN MOVES SOUTH THIS EVENING.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN WINDS AND
WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...WCH
MARINE...JJR/SAGE
000
FXUS61 KBUF 190852
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
352 AM EST MON JAN 19 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NEAR LAKE ONTARIO WILL CONTINUE TO WEAKEN AND
MOVE NORTHEAST TODAY. A FRESH SUPPLY OF COLD AIR ON THE BACK SIDE OF
THIS SYSTEM WILL KEEP SCATTERED SNOW SHOWERS ACROSS THE REGION
THROUGH TUESDAY...ESPECIALLY SOUTHEAST OF THE LAKES. A SLOW WARMING
TREND IS THEN EXPECTED TO BEGIN WEDNESDAY AND CONTINUE THROUGH THE
END OF THE WEEK BEFORE ANOTHER ARCTIC AIRMASS ARRIVES OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE LOW OVER SOUTHERN ONTARIO BETWEEN LAKES ERIE AND HURON WILL
REMAIN IN PLACE OR MOVE SLIGHTLY TO THE EAST AS IT FILLS DURING THE
DAY. WILL KEEP UPPER CHANCE TO LOW LIKELY POPS ACROSS THE AREAS WAY
FROM LAKE INFLUENCES AS A VORT MAX IS FORECAST TO TRACK AROUND THE
UPPER LOW AND LIFT FROM THE OHIO VALLEY TO CENTRAL NY AND PA BETWEEN
12Z AND 21Z.
COLD 850MB TEMPS OF -16C ACROSS BOTH LAKES ERIE AND ONTARIO WILL
MAINTAIN SOME LIMITED LAKE EFFECT SNOW. THE LAKE INDUCED EQUILIBRIUM
LEVEL IS AROUND 7-9KFT THROUGH THE EVENING...LIMITED BY A MID LEVEL
ISOTHERMAL OR INVERSION LAYER EFFECTIVELY CAPPING THE VERTICAL
GROWTH OF LAKE EFFECT. THIS IS STILL DEEP ENOUGH AND COLD ENOUGH AND
BOUNDING THE DENDRITIC GROWTH ZONE...SO WE DO EXPECT A CONTINUATION
OF LIGHT TO MODERATE LAKE SNOWS...THE BIG QUESTION IS WHERE THE LAKE
SNOWS BANDS WILL SET UP. THE PROXIMITY OF THE SURFACE LOW AND THE
SHEAR IN THE BOUNDARY LAYER WILL DEFINE THE PLACEMENT OF THE
SNOWBANDS.
OFF LAKE ERIE...ICE COVER OVER ALL BUT THE NORTHEAST QUARTER OF THE
LAKE WILL REDUCE THE EFFECTIVENESS OF LAKE EFFECT. SOUTH/SOUTHWEST
WINDS WILL INITIALLY ORIENT THE SNOW OVER NORTHERN ERIE AND NIAGARA
COUNTIES EARLY THIS MORNING...THEN A SHIFT TO SOUTHWEST/WESTERLY
WIND WILL FOCUS MULTIBANDED LAKE EFFECT TO THE SOUTHERN TIER AND
SOUTHERN ERIE COUNTY DURING THE AFTERNOON AND INTO TONIGHT.
FOR LAKE ONTARIO...THE MAJORITY OF THE LAKE IS ICE FREE AND CAPABLE
OF SUPPORTING MORE ROBUST LAKE SNOW...BUT WILL ALSO BE HELD IN CHECK
BY THE CAP ALOFT. EARLY TODAY...THE WINDS WILL DIRECT THE SNOW BAND
TO THE NORTHERN SHORE ON SOUTHWEST SURFACE WINDS...BUT FILLING OF
THE SURFACE LOW AND THE REMAINING TROUGH OF LOW PRESSURE OVER LAKE
ONTARIO WILL SHIFT THE SNOW BAND TO THE NORTHEASTERN SHORE OF THE
LAKE THIS AFTERNOON...AND THEN MORE NORTHERLY WINDS TONIGHT WILL
FORCE THE SNOW TO THE SOUTH SHORE.
TEMPS TODAY WILL BE MAINLY IN THE LOWER TO MIDDLE 20S WITH SOME
TEENS OVER THE SOUTHERN TIER AND EAST OF LAKE ONTARIO. OVERNIGHT
LOWS WILL FALL BACK TO THE MID TEENS TO MIDDLE SINGLE NUMBERS AS
COLD AIR FOLLOWS THE NORTHWEST/NORTHERLY WINDS.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
A HIGH AMPLITUDE UPPER TROUGH WILL CONTINUE TO BE ENTRENCHED
OVER THE EASTERN HALF OF THE CONTINENT AT THE BEGINNING OF THIS
PERIOD WITH A SURFACE LOW POSITIONED WELL OFF THE MID ATLANTIC COAST
AND A RIDGE OF HIGH PRESSURE EXTENDING FROM TEXAS TO THE UPPER GREAT
LAKES. THE RESULT ACROSS OUR REGION WILL BE A NORTHWEST FLOW OF COLD
AIR WITH 850 TEMPERATURES FORECAST TO BE IN THE MINUS 14C TO MINUS
16C RANGE. ALTHOUGH THERE WILL BE SOME WARMING ABOVE THE 850 MB
LEVEL THE LOW LEVEL COLD AIR REMAINS DEEP AND MOIST ENOUGH FOR MINOR
LAKE EFFECT SNOW SHOWERS. THE HIGHEST POPS WILL BE OVER THE COUNTIES
JUST SOUTH OF LAKE ONTARIO BUT WE WILL MENTION AT LEAST SCATTERED
SNOW SHOWERS EVERYWHERE. AT THIS TIME WE DO NOT EXPECTED ANY
IMPORTANT ACCUMULATIONS. THE SURFACE RIDGE IS EXPECTED TO CREST OVER
THE REGION LATE TUESDAY NIGHT BUT THE 850 MB RIDGE REMAINS JUST TO
THE WEST EVEN BY 12Z WEDNESDAY SO SCATTERED SNOW SHOWERS ARE
EXPECTED SOUTHEAST OF BOTH LAKES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED BY ANOTHER
SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER TROUGHING OVER THE
EASTERN THIRD OF THE CONTINENT BRIEFLY GETS REINFORCED.
THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL MIDWINTER
TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK OF THE
MONTH AS THE FLOW ALOFT TRENDS TO MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WARMING ALOFT AND A WEAK SURFACE PATTERN
SHOULD PROVIDE THE AREA WITH PRETTY MUCH A BENIGN WEATHER DAY ON
THURSDAY. THE LATEST ECMWF IS VERY CLOSE TO YESTERDAY/S RUN WHEREAS
THE GFS HAS HAD A LOT OF RUN TO RUN DIFFERENCES. WE WILL STAY WITH
THE ECMWF SOLUTION FOR FRIDAY THROUGH THE WEEKEND WITH A CLIPPER
SYSTEM CROSSING THE AREA FRIDAY. FOLLOWING THE PASSAGE OF THIS
LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR THE UPCOMING
WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
COLDER THAN MINUS 20C FOR THE WEEKEND...THERE WILL DEFINITELY BE
SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A MOIST CYCLONIC FLOW BEHIND A WEAKENING OCCLUDED FRONT WILL
CONTINUE TO GENERATE SOME LIGHT SNOW...ACCOMPANIED BY OCCASIONAL
MVFR CIGS/VSBYS. THE SNOW WILL BE MORE STEADY NORTHEAST OF LAKE ERIE
WHERE THERE WILL BE AN ADDITIONAL INFLUX OF MOISTURE FROM THE LAKE.
THIS WILL ALLOW VSBYS TO LOWER TO IFR AT TIMES VCNTY KBUF/KIAG.
EXPECT A SIMILAR TREND TO DEVELOP EAST OF LAKE ONTARIO LATE TONIGHT.
AN APPROACHING UPPER LEVEL TROUGH COMBINED WITH THE MOIST
CIRCULATION AROUND THE DEPARTING LOW WILL MAINTAIN MAINLY MVFR CIGS
ACROSS THE AREA MONDAY. EXPECT VSBYS TO LOWER TO MVFR AT TIMES IN
-SHSN.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK PRESSURE GRADIENT WILL CONTINUE ACROSS THE LOWER
LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN WINDS AND
WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TJP
MARINE...JJR/SAGE
000
FXUS61 KBUF 190453
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1153 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED JUST SOUTH OF GEORGIAN BAY WILL DRIFT SLOWLY
EAST TO LAKE ONTARIO BY MONDAY MORNING...THEN WILL GRADUALLY
DISSIPATE OVER THE LAKE MONDAY AND MONDAY NIGHT AS A SECONDARY LOW
LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. A NORTHWESTERLY FLOW OF
SEASONABLY COLD AIR ON THE BACK SIDE OF THIS SYSTEM WILL KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY. SOMEWHAT MILDER AIR IS THEN EXPECTED TO WORK INTO THE AREA
FOR WEDNESDAY AND THURSDAY...BEFORE ANOTHER ARCTIC AIRMASS ARRIVES
AT THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
THE OCCLUDED FRONT THAT EXTENDS EAST OF THE STALLED SURFACE
LOW...LOCATED JUST EAST OF LAKE HURON...HAS MOVED EAST EAST OF A
ROCHESTER TO WELLSVILLE LINE. THE STEADIER SNOW THAT FORMED ALONG
THIS BOUNDARY DURING THE LATE AFTERNOON/EARLY EVENING HAS DIMINISHED
IN INTENSITY...BUT LIGHT SNOW IS STILL FORMING IN THE MOIST CYCLONIC
FLOW THAT LINGERS BEHIND THE DEPARTING FRONT. EXPECT THIS TREND TO
CONTINUE THROUGH THE NIGHT...BUT ADDITIONAL ACCUMULATIONS WILL
GENERALLY BE AN INCH OR LESS. THEREFORE...WILL LET THE WINTER
WEATHER ADVISORY EXPIRE AT 10 PM.
KBUF RADAR DOES SHOW HIGHER RETURNS OVER SOUTHERN ERIE COUNTY WHERE
SOME ENHANCEMENT IS OCCURRING OFF LAKE ERIE. THIS STEADIER SNOW MAY
MIGRATE NORTH INTO NORTHERN ERIE COUNTY AT TIMES...BUT THE
INCREASING LOW LEVEL WIND SHEAR AND PRESENCE OF ICE ON THE LAKE
SHOULD KEEP ACCUMULATIONS BELOW ADVISORY CRITERIA.
A SIMILAR TREND IS EXPECTED EAST OF LAKE ONTARIO AFTER A WEST TO
SOUTHWEST FLOW SETS UP EAST OF THE LAKE LATE TONIGHT.
ONCE AGAIN...ADDITIONAL ACCUMULATIONS ARE EXPECTED TO REMAIN UNDER
ADVISORY CRITERIA. THE FLOW DOES LOOK TO BACK MORE SOUTH
SOUTHWESTERLY MONDAY AND THIS WILL LIFT ANY LAKE SNOWS OFF LAKE
ONTARIO NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING LOW WILL
MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE AREA
DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE REMNANT INVERTED TROUGH LEFTOVER FROM
THIS WEEKEND`S CLIPPER SYSTEM WILL GRADUALLY DISSIPATE AS A
SECONDARY LOW LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. IN
RESPONSE...A NORTH TO NORTH-NORTHWESTERLY FLOW OF COLD AIR WILL
OVERSPREAD THE REGION MONDAY NIGHT...THEN WILL CONTINUE THROUGH
TUESDAY...BEFORE TURNING MORE WESTERLY AND MODERATING A BIT TUESDAY
NIGHT IN ADVANCE OF THE NEXT SYSTEM WORKING ACROSS ONTARIO PROVINCE.
THIS WILL BE REFLECTED IN 850 MB TEMPERATURES FALLING FROM ABOUT
-14C MONDAY EVENING TO -17C TUESDAY EVENING...BEFORE REBOUNDING BACK
TO THE -13C TO -16C RANGE BY WEDNESDAY MORNING. WHILE SUCH VALUES
WILL LEAD TO SURFACE READINGS AVERAGING A BIT BELOW NORMAL THROUGH
THE PERIOD...IT WILL BE NOWHERE NEAR AS COLD AS THE BITTERLY COLD
WEATHER WE EXPERIENCED LAST WEEK.
WITH THE AFOREMENTIONED COLD TEMPERATURES ALOFT AND A DECENT AMOUNT
OF MOISTURE LINGERING IN THE LOWEST 7-8 KFT OF THE ATMOSPHERE
THROUGH TUESDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE DOWNWIND OF
THE LAKES...PARTICULARLY OFF OF LAKE ONTARIO WHICH HAS NOWHERE NEAR
THE AMOUNT OF ICE COVERAGE AS LAKE ERIE. THAT SAID...THE PREVAILING
NORTH TO NORTHWESTERLY FLOW WILL KEEP THE ACTIVITY FOCUSED
SOUTH-SOUTHEAST OF THE LAKES...WITH THE RELATIVELY SHORT FETCH
HELPING TO LIMIT THE ORGANIZATION OF THE BANDS...AND AS A
CONSEQUENCE ANY RESULTING ACCUMULATIONS. WILL GENERALLY FORECAST
LIKELY POPS AND MINOR ACCUMS IN THE COUNTIES BORDERING THE SOUTH
SHORES OF BOTH LAKES DURING THIS TIME FRAME...WITH CHANCE POPS AND A
MENTION OF SCATTERED SNOW SHOWERS FOUND ACROSS THE REMAINDER OF THE
AREA. WILL ALSO HAVE SOME LINGERING LIKELY POPS/MINOR ACCUMS ACROSS
THE NORTH COUNTRY EARLY MONDAY EVENING...MAINLY TO COVER THE ENDING
OF ANY LINGERING SYNOPTIC-SCALE PRECIP ASSOCIATED WITH THE
DISSIPATING INVERTED TROUGH.
DURING TUESDAY NIGHT...THE LOW-LEVEL FLOW WILL GRADUALLY TURN MORE
WEST-NORTHWESTERLY...AND THEN WESTERLY IN ADVANCE OF THE NEXT SYSTEM
THAT WILL BE WORKING ACROSS NORTHERN ONTARIO. THIS WILL TEND TO
FOCUS THE LAKE SNOWS A LITTLE MORE TO THE NORTH AND EAST AS TIME
PROGRESSES...THOUGH THE ACTIVITY SHOULD ALSO BE WEAKENING AS
INVERSION HEIGHTS BEGIN TO CRASH AND LOW-LEVEL MOISTURE DECREASES.
FOR THESE REASONS...NOTHING HIGHER THAN CHANCE POPS WILL BE USED FOR
TUESDAY NIGHT`S LAKE EFFECT ACTIVITY AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE
SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED
BY ANOTHER SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER
TROUGHING OVER THE EASTERN THIRD OF THE CONTINENT BRIEFLY GETS
REINFORCED. THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL
MIDWINTER TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK
OF THE MONTH AS THE FLOW ALOFT TRENDS MUCH MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WEAK RIDGING SHOULD PROVIDE THE AREA WITH A
DRY DAY ON THURSDAY...BEFORE ANOTHER CLIPPER SYSTEM APPROACHES AND
CROSSES THE AREA THURSDAY NIGHT AND FRIDAY. FOLLOWING THE PASSAGE OF
THIS LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY
NIGHT AND THE UPCOMING WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
AROUND -20C FOR FRIDAY NIGHT AND THE WEEKEND...THERE WILL DEFINITELY
BE SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A MOIST CYCLONIC FLOW BEHIND A WEAKENING OCCLUDED FRONT WILL
CONTINUE TO GENERATE SOME LIGHT SNOW...ACCOMPANIED BY OCCASIONAL
MVFR CIGS/VSBYS. THE SNOW WILL BE MORE STEADY NORTHEAST OF LAKE ERIE
WHERE THERE WILL BE AN ADDITIONAL INFLUX OF MOISTURE FROM THE LAKE.
THIS WILL ALLOW VSBYS TO LOWER TO IFR AT TIMES VCNTY KBUF/KIAG.
EXPECT A SIMILAR TREND TO DEVELOP EAST OF LAKE ONTARIO LATE TONIGHT.
AN APPROACHING UPPER LEVEL TROUGH COMBINED WITH THE MOIST
CIRCULATION AROUND THE DEPARTING LOW WILL MAINTAIN MAINLY MVFR CIGS
ACROSS THE AREA MONDAY. EXPECT VSBYS TO LOWER TO MVFR AT TIMES IN
-SHSN.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK TO MODERATE PRESSURE GRADIENT WILL CONTINUE ACROSS
THE LOWER LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN
WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TJP/TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TJP
MARINE...JJR
000
FXUS61 KBUF 190245
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
945 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED JUST SOUTH OF GEORGIAN BAY WILL DRIFT SLOWLY
EAST TO LAKE ONTARIO BY MONDAY MORNING...THEN WILL GRADUALLY
DISSIPATE OVER THE LAKE MONDAY AND MONDAY NIGHT AS A SECONDARY LOW
LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. A NORTHWESTERLY FLOW OF
SEASONABLY COLD AIR ON THE BACK SIDE OF THIS SYSTEM WILL KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY. SOMEWHAT MILDER AIR IS THEN EXPECTED TO WORK INTO THE AREA
FOR WEDNESDAY AND THURSDAY...BEFORE ANOTHER ARCTIC AIRMASS ARRIVES
AT THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
THE OCCLUDED FRONT THAT EXTENDS EAST OF THE STALLED SURFACE
LOW...LOCATED JUST EAST OF LAKE HURON...HAS MOVED EAST EAST OF A
ROCHESTER TO WELLSVILLE LINE. THE STEADIER SNOW THAT FORMED ALONG
THIS BOUNDARY DURING THE LATE AFTERNOON/EARLY EVENING HAS DIMINISHED
IN INTENSITY...BUT LIGHT SNOW IS STILL FORMING IN THE MOIST CYCLONIC
FLOW THAT LINGERS BEHIND THE DEPARTING FRONT. EXPECT THIS TREND TO
CONTINUE THROUGH THE NIGHT...BUT ADDITIONAL ACCUMULATIONS WILL
GENERALLY BE AN INCH OR LESS. THEREFORE...WILL LET THE WINTER
WEATHER ADVISORY EXPIRE AT 10 PM.
KBUF RADAR DOES SHOW HIGHER RETURNS OVER SOUTHERN ERIE COUNTY WHERE
SOME ENHANCEMENT IS OCCURRING OFF LAKE ERIE. THIS STEADIER SNOW MAY
MIGRATE NORTH INTO NORTHERN ERIE COUNTY AT TIMES...BUT THE
INCREASING LOW LEVEL WIND SHEAR AND PRESENCE OF ICE ON THE LAKE
SHOULD KEEP ACCUMULATIONS BELOW ADVISORY CRITERIA.
A SIMILAR TREND IS EXPECTED EAST OF LAKE ONTARIO AFTER A WEST TO
SOUTHWEST FLOW SETS UP EAST OF THE LAKE LATE TONIGHT.
ONCE AGAIN...ADDITIONAL ACCUMULATIONS ARE EXPECTED TO REMAIN UNDER
ADVISORY CRITERIA. THE FLOW DOES LOOK TO BACK MORE SOUTH
SOUTHWESTERLY MONDAY AND THIS WILL LIFT ANY LAKE SNOWS OFF LAKE
ONTARIO NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING LOW WILL
MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE AREA
DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE REMNANT INVERTED TROUGH LEFTOVER FROM
THIS WEEKEND`S CLIPPER SYSTEM WILL GRADUALLY DISSIPATE AS A
SECONDARY LOW LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. IN
RESPONSE...A NORTH TO NORTH-NORTHWESTERLY FLOW OF COLD AIR WILL
OVERSPREAD THE REGION MONDAY NIGHT...THEN WILL CONTINUE THROUGH
TUESDAY...BEFORE TURNING MORE WESTERLY AND MODERATING A BIT TUESDAY
NIGHT IN ADVANCE OF THE NEXT SYSTEM WORKING ACROSS ONTARIO PROVINCE.
THIS WILL BE REFLECTED IN 850 MB TEMPERATURES FALLING FROM ABOUT
-14C MONDAY EVENING TO -17C TUESDAY EVENING...BEFORE REBOUNDING BACK
TO THE -13C TO -16C RANGE BY WEDNESDAY MORNING. WHILE SUCH VALUES
WILL LEAD TO SURFACE READINGS AVERAGING A BIT BELOW NORMAL THROUGH
THE PERIOD...IT WILL BE NOWHERE NEAR AS COLD AS THE BITTERLY COLD
WEATHER WE EXPERIENCED LAST WEEK.
WITH THE AFOREMENTIONED COLD TEMPERATURES ALOFT AND A DECENT AMOUNT
OF MOISTURE LINGERING IN THE LOWEST 7-8 KFT OF THE ATMOSPHERE
THROUGH TUESDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE DOWNWIND OF
THE LAKES...PARTICULARLY OFF OF LAKE ONTARIO WHICH HAS NOWHERE NEAR
THE AMOUNT OF ICE COVERAGE AS LAKE ERIE. THAT SAID...THE PREVAILING
NORTH TO NORTHWESTERLY FLOW WILL KEEP THE ACTIVITY FOCUSED
SOUTH-SOUTHEAST OF THE LAKES...WITH THE RELATIVELY SHORT FETCH
HELPING TO LIMIT THE ORGANIZATION OF THE BANDS...AND AS A
CONSEQUENCE ANY RESULTING ACCUMULATIONS. WILL GENERALLY FORECAST
LIKELY POPS AND MINOR ACCUMS IN THE COUNTIES BORDERING THE SOUTH
SHORES OF BOTH LAKES DURING THIS TIME FRAME...WITH CHANCE POPS AND A
MENTION OF SCATTERED SNOW SHOWERS FOUND ACROSS THE REMAINDER OF THE
AREA. WILL ALSO HAVE SOME LINGERING LIKELY POPS/MINOR ACCUMS ACROSS
THE NORTH COUNTRY EARLY MONDAY EVENING...MAINLY TO COVER THE ENDING
OF ANY LINGERING SYNOPTIC-SCALE PRECIP ASSOCIATED WITH THE
DISSIPATING INVERTED TROUGH.
DURING TUESDAY NIGHT...THE LOW-LEVEL FLOW WILL GRADUALLY TURN MORE
WEST-NORTHWESTERLY...AND THEN WESTERLY IN ADVANCE OF THE NEXT SYSTEM
THAT WILL BE WORKING ACROSS NORTHERN ONTARIO. THIS WILL TEND TO
FOCUS THE LAKE SNOWS A LITTLE MORE TO THE NORTH AND EAST AS TIME
PROGRESSES...THOUGH THE ACTIVITY SHOULD ALSO BE WEAKENING AS
INVERSION HEIGHTS BEGIN TO CRASH AND LOW-LEVEL MOISTURE DECREASES.
FOR THESE REASONS...NOTHING HIGHER THAN CHANCE POPS WILL BE USED FOR
TUESDAY NIGHT`S LAKE EFFECT ACTIVITY AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE
SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED
BY ANOTHER SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER
TROUGHING OVER THE EASTERN THIRD OF THE CONTINENT BRIEFLY GETS
REINFORCED. THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL
MIDWINTER TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK
OF THE MONTH AS THE FLOW ALOFT TRENDS MUCH MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WEAK RIDGING SHOULD PROVIDE THE AREA WITH A
DRY DAY ON THURSDAY...BEFORE ANOTHER CLIPPER SYSTEM APPROACHES AND
CROSSES THE AREA THURSDAY NIGHT AND FRIDAY. FOLLOWING THE PASSAGE OF
THIS LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY
NIGHT AND THE UPCOMING WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
AROUND -20C FOR FRIDAY NIGHT AND THE WEEKEND...THERE WILL DEFINITELY
BE SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
A COLD FRONT...SITUATED BETWEEN KBUF AND KROC THIS EVENING WILL
CONTINUE TO MOVE SLOWLY TO THE EAST AND CLEAR KART AROUND 07Z. AN
AREA OF MAINLY LIGHT SNOW IN THE VCNTY OF THIS FRONT WILL BRING CIGS
DOWN TO MVFR WHILE VSBYS LOWER TO IFR. A MID LEVEL SHORT WAVE
TRACKING EAST ACROSS CENTRAL LAKE ERIE WILL KEEP THE LIGHT SNOW
GOING A FEW HOURS AFTER THE FRONTAL PASSAGE. THEN...EXPECT A GRADUAL
IMPROVEMENT TO VFR CONDITIONS ACROSS WESTERN NEW YORK AND THE
GENESEE VALLEY. LATER TONIGHT...INCREASING LOW LEVEL MOISTURE WILL
ADVECT IN FROM THE CENTRAL GREAT LAKES AND CAUSE CIGS TO LOWER TO
MVFR AGAIN.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK TO MODERATE PRESSURE GRADIENT WILL CONTINUE ACROSS
THE LOWER LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN
WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TJP/TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TJP
MARINE...JJR
000
FXUS61 KBUF 190009
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
709 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED JUST SOUTH OF GEORGIAN BAY WILL DRIFT SLOWLY
EAST TO LAKE ONTARIO BY MONDAY MORNING...THEN WILL GRADUALLY
DISSIPATE OVER THE LAKE MONDAY AND MONDAY NIGHT AS A SECONDARY LOW
LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. A NORTHWESTERLY FLOW OF
SEASONABLY COLD AIR ON THE BACK SIDE OF THIS SYSTEM WILL KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY. SOMEWHAT MILDER AIR IS THEN EXPECTED TO WORK INTO THE AREA
FOR WEDNESDAY AND THURSDAY...BEFORE ANOTHER ARCTIC AIRMASS ARRIVES
AT THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE AT 337 PM...SNOW DEVELOPING ALONG FRONTAL BOUNDARY
PRODUCING RATES OF AT LEAST AN INCH PER HOUR. WILL THEREFORE NEED
TO EXTEND WINTER WEATHER ADVISORY UNTIL 10 PM. COULD SEE
ADDITIONAL ACCUMULATIONS OF 2 TO 3 INCHES ACROSS THE AREA THIS
EVENING.
PREVIOUS DISCUSSION...
KBUF RADAR SHOWING A BURST OF HEAVIER SNOW WITH SNOWFALL RATES
AROUND AN INCH PER HOUR MOVING INTO FAR WESTERN SECTIONS THIS
AFTERNOON...GENERALLY FROM BUFFALO TO JAMESTOWN. THIS IS ASSOCIATED
WITH THE CONVERGENCE ZONE ALONG OCCLUDING FRONTAL BOUNDARY
WORKING INTO THE AREA...AND LIKELY SOME ENHANCEMENT FROM UPPER
IMPULSE LIFTING NORTHEAST INTO THE AREA. NAM12 925MB OMEGA FIELDS
SEEM TO SUGGEST THIS POTENTIAL AND HANDLING IT NICELY. THE MODEL
SHIFTS THIS AREA EASTWARD IN TIME THIS EVENING AND EARLY TONIGHT.
THE ASSOCIATED AREA OF SNOW SHOULD PROGRESS EAST AT A RATE ENOUGH
TO LIMIT ADDITIONAL AMOUNTS TO TWO INCHES OR LESS. WE WILL
MAINTAIN THE WINTER WEATHER ADVISORY UNTIL ITS 4 PM EXPIRATION. AT
THIS POINT...WE DO NOT SEE A REASON TO CONTINUE IT INTO THE
EVENING HOURS...UNLESS RADAR TRENDS CHANGE SIGNIFICANTLY DURING
THE NEXT HOUR OR SO.
ADVECTION OF COLDER AIR...WITH 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C ON A WESTERLY FLOW BEHIND THE FRONTAL BOUNDARY WILL
BRING THE POTENTIAL FOR SOME LIMITED LAKE ENHANCED SNOWS OFF OF
LAKE ERIE DURING THE EVENING AND LASTING INTO THE NIGHT.
HOWEVER...MODEL SOUNDING SUGGESTING THERE WILL BE A FAIR AMOUNT OF
SHEAR AS LOW PRESSURE OVER LAKE HURON DRIFTS ACROSS THE LOWER
LAKES. WE SEE ONLY LIMITED ACCUMULATION POTENTIAL HERE.
ANOTHER AREA OF LAKE SNOW WILL SET UP OFF LAKE ONTARIO LATER
TONIGHT AS THE WESTERLY FLOW BECOMES A LITTLE BETTER ALIGNED WITH
THE FILLING OF THE SURFACE LOW. NAM12 925 OMEGA FIELDS SHOWING
THIS POTENTIAL FROM AROUND 06Z TO 12Z. LAKE PARAMETERS ARE NOT
OVERLY IMPRESSIVE AND ACCUMULATIONS SHOULD BE LIMITED. FLOW DOES
LOOK TO BACK MORE SOUTH SOUTHWESTERLY MONDAY AND THIS WILL LIFT
ANY LAKE SNOWS NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING
LOW WILL MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE
AREA DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE REMNANT INVERTED TROUGH LEFTOVER FROM
THIS WEEKEND`S CLIPPER SYSTEM WILL GRADUALLY DISSIPATE AS A
SECONDARY LOW LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. IN
RESPONSE...A NORTH TO NORTH-NORTHWESTERLY FLOW OF COLD AIR WILL
OVERSPREAD THE REGION MONDAY NIGHT...THEN WILL CONTINUE THROUGH
TUESDAY...BEFORE TURNING MORE WESTERLY AND MODERATING A BIT TUESDAY
NIGHT IN ADVANCE OF THE NEXT SYSTEM WORKING ACROSS ONTARIO PROVINCE.
THIS WILL BE REFLECTED IN 850 MB TEMPERATURES FALLING FROM ABOUT
-14C MONDAY EVENING TO -17C TUESDAY EVENING...BEFORE REBOUNDING BACK
TO THE -13C TO -16C RANGE BY WEDNESDAY MORNING. WHILE SUCH VALUES
WILL LEAD TO SURFACE READINGS AVERAGING A BIT BELOW NORMAL THROUGH
THE PERIOD...IT WILL BE NOWHERE NEAR AS COLD AS THE BITTERLY COLD
WEATHER WE EXPERIENCED LAST WEEK.
WITH THE AFOREMENTIONED COLD TEMPERATURES ALOFT AND A DECENT AMOUNT
OF MOISTURE LINGERING IN THE LOWEST 7-8 KFT OF THE ATMOSPHERE
THROUGH TUESDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE DOWNWIND OF
THE LAKES...PARTICULARLY OFF OF LAKE ONTARIO WHICH HAS NOWHERE NEAR
THE AMOUNT OF ICE COVERAGE AS LAKE ERIE. THAT SAID...THE PREVAILING
NORTH TO NORTHWESTERLY FLOW WILL KEEP THE ACTIVITY FOCUSED
SOUTH-SOUTHEAST OF THE LAKES...WITH THE RELATIVELY SHORT FETCH
HELPING TO LIMIT THE ORGANIZATION OF THE BANDS...AND AS A
CONSEQUENCE ANY RESULTING ACCUMULATIONS. WILL GENERALLY FORECAST
LIKELY POPS AND MINOR ACCUMS IN THE COUNTIES BORDERING THE SOUTH
SHORES OF BOTH LAKES DURING THIS TIME FRAME...WITH CHANCE POPS AND A
MENTION OF SCATTERED SNOW SHOWERS FOUND ACROSS THE REMAINDER OF THE
AREA. WILL ALSO HAVE SOME LINGERING LIKELY POPS/MINOR ACCUMS ACROSS
THE NORTH COUNTRY EARLY MONDAY EVENING...MAINLY TO COVER THE ENDING
OF ANY LINGERING SYNOPTIC-SCALE PRECIP ASSOCIATED WITH THE
DISSIPATING INVERTED TROUGH.
DURING TUESDAY NIGHT...THE LOW-LEVEL FLOW WILL GRADUALLY TURN MORE
WEST-NORTHWESTERLY...AND THEN WESTERLY IN ADVANCE OF THE NEXT SYSTEM
THAT WILL BE WORKING ACROSS NORTHERN ONTARIO. THIS WILL TEND TO
FOCUS THE LAKE SNOWS A LITTLE MORE TO THE NORTH AND EAST AS TIME
PROGRESSES...THOUGH THE ACTIVITY SHOULD ALSO BE WEAKENING AS
INVERSION HEIGHTS BEGIN TO CRASH AND LOW-LEVEL MOISTURE DECREASES.
FOR THESE REASONS...NOTHING HIGHER THAN CHANCE POPS WILL BE USED FOR
TUESDAY NIGHT`S LAKE EFFECT ACTIVITY AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE
SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED
BY ANOTHER SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER
TROUGHING OVER THE EASTERN THIRD OF THE CONTINENT BRIEFLY GETS
REINFORCED. THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL
MIDWINTER TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK
OF THE MONTH AS THE FLOW ALOFT TRENDS MUCH MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WEAK RIDGING SHOULD PROVIDE THE AREA WITH A
DRY DAY ON THURSDAY...BEFORE ANOTHER CLIPPER SYSTEM APPROACHES AND
CROSSES THE AREA THURSDAY NIGHT AND FRIDAY. FOLLOWING THE PASSAGE OF
THIS LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY
NIGHT AND THE UPCOMING WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
AROUND -20C FOR FRIDAY NIGHT AND THE WEEKEND...THERE WILL DEFINITELY
BE SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A COLD FRONT...SITUATED BETWEEN KBUF AND KROC THIS EVENING WILL
CONTINUE TO MOVE SLOWLY TO THE EAST AND CLEAR KART AROUND 07Z. AN
AREA OF MAINLY LIGHT SNOW IN THE VCNTY OF THIS FRONT WILL BRING CIGS
DOWN TO MVFR WHILE VSBYS LOWER TO IFR. A MID LEVEL SHORT WAVE
TRACKING EAST ACROSS CENTRAL LAKE ERIE WILL KEEP THE LIGHT SNOW
GOING A FEW HOURS AFTER THE FRONTAL PASSAGE. THEN...EXPECT A GRADUAL
IMPROVEMENT TO VFR CONDITIONS ACROSS WESTERN NEW YORK AND THE
GENESEE VALLEY. LATER TONIGHT...INCREASING LOW LEVEL MOISTURE WILL
ADVECT IN FROM THE CENTRAL GREAT LAKES AND CAUSE CIGS TO LOWER TO
MVFR AGAIN.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK TO MODERATE PRESSURE GRADIENT WILL CONTINUE ACROSS
THE LOWER LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN
WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TJP
MARINE...JJR
000
FXUS61 KBUF 182038
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
338 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED JUST SOUTH OF GEORGIAN BAY WILL DRIFT SLOWLY
EAST TO LAKE ONTARIO BY MONDAY MORNING...THEN WILL GRADUALLY
DISSIPATE OVER THE LAKE MONDAY AND MONDAY NIGHT AS A SECONDARY LOW
LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. A NORTHWESTERLY FLOW OF
SEASONABLY COLD AIR ON THE BACK SIDE OF THIS SYSTEM WILL KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY. SOMEWHAT MILDER AIR IS THEN EXPECTED TO WORK INTO THE AREA
FOR WEDNESDAY AND THURSDAY...BEFORE ANOTHER ARCTIC AIRMASS ARRIVES
AT THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE AT 337 PM...SNOW DEVELOPING ALONG FRONTAL BOUNDARY
PRODUCING RATES OF AT LEAST AN INCH PER HOUR. WILL THEREFORE NEED
TO EXTEND WINTER WEATHER ADVISORY UNTIL 10 PM. COULD SEE
ADDITIONAL ACCUMULATIONS OF 2 TO 3 INCHES ACROSS THE AREA THIS
EVENING.
PREVIOUS DISCUSSION...
KBUF RADAR SHOWING A BURST OF HEAVIER SNOW WITH SNOWFALL RATES
AROUND AN INCH PER HOUR MOVING INTO FAR WESTERN SECTIONS THIS
AFTERNOON...GENERALLY FROM BUFFALO TO JAMESTOWN. THIS IS ASSOCIATED
WITH THE CONVERGENCE ZONE ALONG OCCLUDING FRONTAL BOUNDARY
WORKING INTO THE AREA...AND LIKELY SOME ENHANCEMENT FROM UPPER
IMPULSE LIFTING NORTHEAST INTO THE AREA. NAM12 925MB OMEGA FIELDS
SEEM TO SUGGEST THIS POTENTIAL AND HANDLING IT NICELY. THE MODEL
SHIFTS THIS AREA EASTWARD IN TIME THIS EVENING AND EARLY TONIGHT.
THE ASSOCIATED AREA OF SNOW SHOULD PROGRESS EAST AT A RATE ENOUGH
TO LIMIT ADDITIONAL AMOUNTS TO TWO INCHES OR LESS. WE WILL
MAINTAIN THE WINTER WEATHER ADVISORY UNTIL ITS 4 PM EXPIRATION. AT
THIS POINT...WE DO NOT SEE A REASON TO CONTINUE IT INTO THE
EVENING HOURS...UNLESS RADAR TRENDS CHANGE SIGNIFICANTLY DURING
THE NEXT HOUR OR SO.
ADVECTION OF COLDER AIR...WITH 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C ON A WESTERLY FLOW BEHIND THE FRONTAL BOUNDARY WILL
BRING THE POTENTIAL FOR SOME LIMITED LAKE ENHANCED SNOWS OFF OF
LAKE ERIE DURING THE EVENING AND LASTING INTO THE NIGHT.
HOWEVER...MODEL SOUNDING SUGGESTING THERE WILL BE A FAIR AMOUNT OF
SHEAR AS LOW PRESSURE OVER LAKE HURON DRIFTS ACROSS THE LOWER
LAKES. WE SEE ONLY LIMITED ACCUMULATION POTENTIAL HERE.
ANOTHER AREA OF LAKE SNOW WILL SET UP OFF LAKE ONTARIO LATER
TONIGHT AS THE WESTERLY FLOW BECOMES A LITTLE BETTER ALIGNED WITH
THE FILLING OF THE SURFACE LOW. NAM12 925 OMEGA FIELDS SHOWING
THIS POTENTIAL FROM AROUND 06Z TO 12Z. LAKE PARAMETERS ARE NOT
OVERLY IMPRESSIVE AND ACCUMULATIONS SHOULD BE LIMITED. FLOW DOES
LOOK TO BACK MORE SOUTH SOUTHWESTERLY MONDAY AND THIS WILL LIFT
ANY LAKE SNOWS NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING
LOW WILL MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE
AREA DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE REMNANT INVERTED TROUGH LEFTOVER FROM
THIS WEEKEND`S CLIPPER SYSTEM WILL GRADUALLY DISSIPATE AS A
SECONDARY LOW LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. IN
RESPONSE...A NORTH TO NORTH-NORTHWESTERLY FLOW OF COLD AIR WILL
OVERSPREAD THE REGION MONDAY NIGHT...THEN WILL CONTINUE THROUGH
TUESDAY...BEFORE TURNING MORE WESTERLY AND MODERATING A BIT TUESDAY
NIGHT IN ADVANCE OF THE NEXT SYSTEM WORKING ACROSS ONTARIO PROVINCE.
THIS WILL BE REFLECTED IN 850 MB TEMPERATURES FALLING FROM ABOUT
-14C MONDAY EVENING TO -17C TUESDAY EVENING...BEFORE REBOUNDING BACK
TO THE -13C TO -16C RANGE BY WEDNESDAY MORNING. WHILE SUCH VALUES
WILL LEAD TO SURFACE READINGS AVERAGING A BIT BELOW NORMAL THROUGH
THE PERIOD...IT WILL BE NOWHERE NEAR AS COLD AS THE BITTERLY COLD
WEATHER WE EXPERIENCED LAST WEEK.
WITH THE AFOREMENTIONED COLD TEMPERATURES ALOFT AND A DECENT AMOUNT
OF MOISTURE LINGERING IN THE LOWEST 7-8 KFT OF THE ATMOSPHERE
THROUGH TUESDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE DOWNWIND OF
THE LAKES...PARTICULARLY OFF OF LAKE ONTARIO WHICH HAS NOWHERE NEAR
THE AMOUNT OF ICE COVERAGE AS LAKE ERIE. THAT SAID...THE PREVAILING
NORTH TO NORTHWESTERLY FLOW WILL KEEP THE ACTIVITY FOCUSED
SOUTH-SOUTHEAST OF THE LAKES...WITH THE RELATIVELY SHORT FETCH
HELPING TO LIMIT THE ORGANIZATION OF THE BANDS...AND AS A
CONSEQUENCE ANY RESULTING ACCUMULATIONS. WILL GENERALLY FORECAST
LIKELY POPS AND MINOR ACCUMS IN THE COUNTIES BORDERING THE SOUTH
SHORES OF BOTH LAKES DURING THIS TIME FRAME...WITH CHANCE POPS AND A
MENTION OF SCATTERED SNOW SHOWERS FOUND ACROSS THE REMAINDER OF THE
AREA. WILL ALSO HAVE SOME LINGERING LIKELY POPS/MINOR ACCUMS ACROSS
THE NORTH COUNTRY EARLY MONDAY EVENING...MAINLY TO COVER THE ENDING
OF ANY LINGERING SYNOPTIC-SCALE PRECIP ASSOCIATED WITH THE
DISSIPATING INVERTED TROUGH.
DURING TUESDAY NIGHT...THE LOW-LEVEL FLOW WILL GRADUALLY TURN MORE
WEST-NORTHWESTERLY...AND THEN WESTERLY IN ADVANCE OF THE NEXT SYSTEM
THAT WILL BE WORKING ACROSS NORTHERN ONTARIO. THIS WILL TEND TO
FOCUS THE LAKE SNOWS A LITTLE MORE TO THE NORTH AND EAST AS TIME
PROGRESSES...THOUGH THE ACTIVITY SHOULD ALSO BE WEAKENING AS
INVERSION HEIGHTS BEGIN TO CRASH AND LOW-LEVEL MOISTURE DECREASES.
FOR THESE REASONS...NOTHING HIGHER THAN CHANCE POPS WILL BE USED FOR
TUESDAY NIGHT`S LAKE EFFECT ACTIVITY AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE
SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED
BY ANOTHER SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER
TROUGHING OVER THE EASTERN THIRD OF THE CONTINENT BRIEFLY GETS
REINFORCED. THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL
MIDWINTER TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK
OF THE MONTH AS THE FLOW ALOFT TRENDS MUCH MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WEAK RIDGING SHOULD PROVIDE THE AREA WITH A
DRY DAY ON THURSDAY...BEFORE ANOTHER CLIPPER SYSTEM APPROACHES AND
CROSSES THE AREA THURSDAY NIGHT AND FRIDAY. FOLLOWING THE PASSAGE OF
THIS LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY
NIGHT AND THE UPCOMING WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
AROUND -20C FOR FRIDAY NIGHT AND THE WEEKEND...THERE WILL DEFINITELY
BE SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MAINLY LIGHT SNOW WILL CONTINUE ACROSS THE AREA THIS MORNING AND
EVENING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER LAKE HURON. CEILINGS WILL BE MAINLY MVFR THROUGH THIS
EVENING WITH PERIODS OF IFR VSBYS. EXPECT LOWER CEILINGS BORDERING
MVFR AND IFR THIS EVENING AND TONIGHT ALONG THE EASTERN SHORE OF
LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH PERIODS OF IFR VSBY IN
SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK TO MODERATE PRESSURE GRADIENT WILL CONTINUE ACROSS
THE LOWER LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN
WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TMA/WCH
MARINE...JJR
000
FXUS61 KBUF 182004
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
304 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED JUST SOUTH OF GEORGIAN BAY WILL DRIFT SLOWLY
EAST TO LAKE ONTARIO BY MONDAY MORNING...THEN WILL GRADUALLY
DISSIPATE OVER THE LAKE MONDAY AND MONDAY NIGHT AS A SECONDARY LOW
LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. A NORTHWESTERLY FLOW OF
SEASONABLY COLD AIR ON THE BACK SIDE OF THIS SYSTEM WILL KEEP
SCATTERED TO NUMEROUS SNOW SHOWERS ACROSS THE REGION THROUGH
TUESDAY. SOMEWHAT MILDER AIR IS THEN EXPECTED TO WORK INTO THE AREA
FOR WEDNESDAY AND THURSDAY...BEFORE ANOTHER ARCTIC AIRMASS ARRIVES
AT THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
KBUF RADAR SHOWING A BURST OF HEAVIER SNOW WITH SNOWFALL RATES
AROUND AN INCH PER HOUR MOVING INTO FAR WESTERN SECTIONS THIS
AFTERNOON...GENERALLY FROM BUFFALO TO JAMESTOWN. THIS IS ASSOCIATED
WITH THE CONVERGENCE ZONE ALONG OCCLUDING FRONTAL BOUNDARY
WORKING INTO THE AREA...AND LIKELY SOME ENHANCEMENT FROM UPPER
IMPULSE LIFTING NORTHEAST INTO THE AREA. NAM12 925MB OMEGA FIELDS
SEEM TO SUGGEST THIS POTENTIAL AND HANDLING IT NICELY. THE MODEL
SHIFTS THIS AREA EASTWARD IN TIME THIS EVENING AND EARLY TONIGHT.
THE ASSOCIATED AREA OF SNOW SHOULD PROGRESS EAST AT A RATE ENOUGH
TO LIMIT ADDITIONAL AMOUNTS TO TWO INCHES OR LESS. WE WILL
MAINTAIN THE WINTER WEATHER ADVISORY UNTIL ITS 4 PM EXPIRATION. AT
THIS POINT...WE DO NOT SEE A REASON TO CONTINUE IT INTO THE
EVENING HOURS...UNLESS RADAR TRENDS CHANGE SIGNIFICANTLY DURING
THE NEXT HOUR OR SO.
ADVECTION OF COLDER AIR...WITH 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C ON A WESTERLY FLOW BEHIND THE FRONTAL BOUNDARY WILL
BRING THE POTENTIAL FOR SOME LIMITED LAKE ENHANCED SNOWS OFF OF
LAKE ERIE DURING THE EVENING AND LASTING INTO THE NIGHT.
HOWEVER...MODEL SOUNDING SUGGESTING THERE WILL BE A FAIR AMOUNT OF
SHEAR AS LOW PRESSURE OVER LAKE HURON DRIFTS ACROSS THE LOWER
LAKES. WE SEE ONLY LIMITED ACCUMULATION POTENTIAL HERE.
ANOTHER AREA OF LAKE SNOW WILL SET UP OFF LAKE ONTARIO LATER
TONIGHT AS THE WESTERLY FLOW BECOMES A LITTLE BETTER ALIGNED WITH
THE FILLING OF THE SURFACE LOW. NAM12 925 OMEGA FIELDS SHOWING
THIS POTENTIAL FROM AROUND 06Z TO 12Z. LAKE PARAMETERS ARE NOT
OVERLY IMPRESSIVE AND ACCUMULATIONS SHOULD BE LIMITED. FLOW DOES
LOOK TO BACK MORE SOUTH SOUTHWESTERLY MONDAY AND THIS WILL LIFT
ANY LAKE SNOWS NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING
LOW WILL MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE
AREA DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE REMNANT INVERTED TROUGH LEFTOVER FROM
THIS WEEKEND`S CLIPPER SYSTEM WILL GRADUALLY DISSIPATE AS A
SECONDARY LOW LIFTS NORTHEAST OFF THE NEW ENGLAND COAST. IN
RESPONSE...A NORTH TO NORTH-NORTHWESTERLY FLOW OF COLD AIR WILL
OVERSPREAD THE REGION MONDAY NIGHT...THEN WILL CONTINUE THROUGH
TUESDAY...BEFORE TURNING MORE WESTERLY AND MODERATING A BIT TUESDAY
NIGHT IN ADVANCE OF THE NEXT SYSTEM WORKING ACROSS ONTARIO PROVINCE.
THIS WILL BE REFLECTED IN 850 MB TEMPERATURES FALLING FROM ABOUT
-14C MONDAY EVENING TO -17C TUESDAY EVENING...BEFORE REBOUNDING BACK
TO THE -13C TO -16C RANGE BY WEDNESDAY MORNING. WHILE SUCH VALUES
WILL LEAD TO SURFACE READINGS AVERAGING A BIT BELOW NORMAL THROUGH
THE PERIOD...IT WILL BE NOWHERE NEAR AS COLD AS THE BITTERLY COLD
WEATHER WE EXPERIENCED LAST WEEK.
WITH THE AFOREMENTIONED COLD TEMPERATURES ALOFT AND A DECENT AMOUNT
OF MOISTURE LINGERING IN THE LOWEST 7-8 KFT OF THE ATMOSPHERE
THROUGH TUESDAY...LAKE EFFECT SNOW SHOWERS WILL CONTINUE DOWNWIND OF
THE LAKES...PARTICULARLY OFF OF LAKE ONTARIO WHICH HAS NOWHERE NEAR
THE AMOUNT OF ICE COVERAGE AS LAKE ERIE. THAT SAID...THE PREVAILING
NORTH TO NORTHWESTERLY FLOW WILL KEEP THE ACTIVITY FOCUSED
SOUTH-SOUTHEAST OF THE LAKES...WITH THE RELATIVELY SHORT FETCH
HELPING TO LIMIT THE ORGANIZATION OF THE BANDS...AND AS A
CONSEQUENCE ANY RESULTING ACCUMULATIONS. WILL GENERALLY FORECAST
LIKELY POPS AND MINOR ACCUMS IN THE COUNTIES BORDERING THE SOUTH
SHORES OF BOTH LAKES DURING THIS TIME FRAME...WITH CHANCE POPS AND A
MENTION OF SCATTERED SNOW SHOWERS FOUND ACROSS THE REMAINDER OF THE
AREA. WILL ALSO HAVE SOME LINGERING LIKELY POPS/MINOR ACCUMS ACROSS
THE NORTH COUNTRY EARLY MONDAY EVENING...MAINLY TO COVER THE ENDING
OF ANY LINGERING SYNOPTIC-SCALE PRECIP ASSOCIATED WITH THE
DISSIPATING INVERTED TROUGH.
DURING TUESDAY NIGHT...THE LOW-LEVEL FLOW WILL GRADUALLY TURN MORE
WEST-NORTHWESTERLY...AND THEN WESTERLY IN ADVANCE OF THE NEXT SYSTEM
THAT WILL BE WORKING ACROSS NORTHERN ONTARIO. THIS WILL TEND TO
FOCUS THE LAKE SNOWS A LITTLE MORE TO THE NORTH AND EAST AS TIME
PROGRESSES...THOUGH THE ACTIVITY SHOULD ALSO BE WEAKENING AS
INVERSION HEIGHTS BEGIN TO CRASH AND LOW-LEVEL MOISTURE DECREASES.
FOR THESE REASONS...NOTHING HIGHER THAN CHANCE POPS WILL BE USED FOR
TUESDAY NIGHT`S LAKE EFFECT ACTIVITY AT THIS TIME.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
IN GENERAL...THE CURRENT STRONG +PNA PATTERN OVER NORTH AMERICA WILL
HAVE A TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE
FORECAST AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY
LESS AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE
SEASONABLE TEMPERATURES FOR THE FIRST HALF OF THE PERIOD...FOLLOWED
BY ANOTHER SHOT OF RATHER COLD AIR FOR NEXT WEEKEND AS UPPER
TROUGHING OVER THE EASTERN THIRD OF THE CONTINENT BRIEFLY GETS
REINFORCED. THEREAFTER...A LONGER-LIVED PERIOD OF MORE NORMAL
MIDWINTER TEMPERATURES MAY EVENTUALLY ARRIVE DURING THE FINAL WEEK
OF THE MONTH AS THE FLOW ALOFT TRENDS MUCH MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FROM MIDWEEK
THROUGH NEXT WEEKEND...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO
ON WEDNESDAY SHOULD DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT
SOUTHEAST INTO THE AREA DURING THE DAY. THIS WILL RESULT IN A
GENERAL CHANCE FOR SOME SNOW SHOWERS...WHICH COULD BE ENHANCED A
LITTLE EAST AND SOUTHEAST OF LAKE ONTARIO GIVEN STILL-COLD 850 MB
TEMPERATURES OF -14C TO -16C. THE LATEST GFS/ECMWF ARE THEN IN
GENERAL AGREEMENT THAT WEAK RIDGING SHOULD PROVIDE THE AREA WITH A
DRY DAY ON THURSDAY...BEFORE ANOTHER CLIPPER SYSTEM APPROACHES AND
CROSSES THE AREA THURSDAY NIGHT AND FRIDAY. FOLLOWING THE PASSAGE OF
THIS LOW...A SHOT OF MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY
NIGHT AND THE UPCOMING WEEKEND.
HAVE GENERALLY CONTINUED WITH MID TO HIGH RANGE CHANCE POPS FOR THE
PASSAGE OF THE CLIPPER SYSTEM THURSDAY NIGHT AND FRIDAY...THEN A
MENTION OF SCATTERED SNOW SHOWERS EVERYWHERE FOR THE REMAINDER OF
THE PERIOD AS THE NEXT ROUND OF ARCTIC AIR FLOODS ACROSS THE REGION
IN THE WAKE OF THE CLIPPER. WITH 850 MB TEMPS LIKELY DROPPING TO
AROUND -20C FOR FRIDAY NIGHT AND THE WEEKEND...THERE WILL DEFINITELY
BE SOME LAKE EFFECT IMPLICATIONS FOR AREAS DOWNWIND OF LAKE
ONTARIO...THOUGH HAVE OPTED NOT TO DELINEATE THESE AT THIS TIME
GIVEN THE STILL-DISTANT VANTAGE POINT. THIS TYPE OF DETAIL CAN BE
ADDED IN FUTURE FORECASTS AS THIS TIME PERIOD DRAWS CLOSER...AND WE
GET A BETTER HANDLE ON POTENTIAL WIND DIRECTIONS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MAINLY LIGHT SNOW WILL CONTINUE ACROSS THE AREA THIS MORNING AND
EVENING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER LAKE HURON. CEILINGS WILL BE MAINLY MVFR THROUGH THIS
EVENING WITH PERIODS OF IFR VSBYS. EXPECT LOWER CEILINGS BORDERING
MVFR AND IFR THIS EVENING AND TONIGHT ALONG THE EASTERN SHORE OF
LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH PERIODS OF IFR VSBY IN
SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
A RELATIVELY WEAK TO MODERATE PRESSURE GRADIENT WILL CONTINUE ACROSS
THE LOWER LAKES REGION THROUGH WEDNESDAY...AND THIS WILL RESULT IN
WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA INTO MIDWEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TMA/WCH
MARINE...JJR
000
FXUS61 KBUF 181954
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
254 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NORTH OF LAKE ERIE THIS MORNING IS FORECAST TO
TRACK VERY SLOWLY TO LAKE ONTARIO BY MONDAY MORNING WHILE A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. A NORTHWEST FLOW ON
THE BACK SIDE OF THIS COMPLEX SYSTEM WILL BRING A FRESH SUPPLY OF
COLDER THAN NORMAL AIR TO THE REGION THROUGH THE FIRST PART OF THE
WEEK BUT NOT AS COLD AS OUR RECENT ARCTIC BLAST. SOMEWHAT MILDER AIR
IS EXPECTED TO MOVE IN DURING MID TO LATE WEEK WITH ANOTHER ARCTIC
AIR MASS SCHEDULED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH MONDAY/...
KBUF RADAR SHOWING A BURST OF HEAVIER SNOW WITH SNOWFALL RATES
AROUND AN INCH PER HOUR MOVING INTO FAR WESTERN SECTIONS THIS
AFTERNOON...GENERALLY FROM BUFFALO TO JAMESTOWN. THIS IS ASSOCIATED
WITH THE CONVERGENCE ZONE ALONG OCCLUDING FRONTAL BOUNDARY
WORKING INTO THE AREA...AND LIKELY SOME ENHANCEMENT FROM UPPER
IMPULSE LIFTING NORTHEAST INTO THE AREA. NAM12 925MB OMEGA FIELDS
SEEM TO SUGGEST THIS POTENTIAL AND HANDLING IT NICELY. THE MODEL
SHIFTS THIS AREA EASTWARD IN TIME THIS EVENING AND EARLY TONIGHT.
THE ASSOCIATED AREA OF SNOW SHOULD PROGRESS EAST AT A RATE ENOUGH
TO LIMIT ADDITIONAL AMOUNTS TO TWO INCHES OR LESS. WE WILL
MAINTAIN THE WINTER WEATHER ADVISORY UNTIL ITS 4 PM EXPIRATION. AT
THIS POINT...WE DO NOT SEE A REASON TO CONTINUE IT INTO THE
EVENING HOURS...UNLESS RADAR TRENDS CHANGE SIGNIFICANTLY DURING
THE NEXT HOUR OR SO.
ADVECTION OF COLDER AIR...WITH 850 MB TEMPERATURES DROPPING TO
NEAR MINUS 15C ON A WESTERLY FLOW BEHIND THE FRONTAL BOUNDARY WILL
BRING THE POTENTIAL FOR SOME LIMITED LAKE ENHANCED SNOWS OFF OF
LAKE ERIE DURING THE EVENING AND LASTING INTO THE NIGHT.
HOWEVER...MODEL SOUNDING SUGGESTING THERE WILL BE A FAIR AMOUNT OF
SHEAR AS LOW PRESSURE OVER LAKE HURON DRIFTS ACROSS THE LOWER
LAKES. WE SEE ONLY LIMITED ACCUMULATION POTENTIAL HERE.
ANOTHER AREA OF LAKE SNOW WILL SET UP OFF LAKE ONTARIO LATER
TONIGHT AS THE WESTERLY FLOW BECOMES A LITTLE BETTER ALIGNED WITH
THE FILLING OF THE SURFACE LOW. NAM12 925 OMEGA FIELDS SHOWING
THIS POTENTIAL FROM AROUND 06Z TO 12Z. LAKE PARAMETERS ARE NOT
OVERLY IMPRESSIVE AND ACCUMULATIONS SHOULD BE LIMITED. FLOW DOES
LOOK TO BACK MORE SOUTH SOUTHWESTERLY MONDAY AND THIS WILL LIFT
ANY LAKE SNOWS NORTHWARD. WRAP AROUND MOISTURE BEHIND DEPARTING
LOW WILL MAINTAIN THE LIKELIHOOD OF SNOW SHOWERS ACROSS THE ENTIRE
AREA DURING THE DAY MONDAY.
&&
.SHORT TERM /MONDAY NIGHT/...
A MODEST MODEL DIFFERENCE BETWEEN THE NAM AND THE GFS MONDAY
MORNING. IN BOTH...THE SLOWED DOWN CLIPPER HANGS BACK AS THE PARENT
UPPER LOW CLOSES OFF OVER LAKE ONTARIO BUT THE GFS KEEPS A STRONGER
SURFACE REFLECTION THAN THE NAM OVER WESTERN LAKE ONTARIO AS A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. IN BOTH SOLUTIONS
HOWEVER...CONDITIONS LOOK UNSTABLE ENOUGH WITH WESTERLY STEERING
WINDS FOR LAKE EFFECT ACTIVITY EAST OF BOTH LAKES. IT IS NOT NEARLY
AS UNSTABLE AS OUR RECENT EVENT BUT LEFTOVER SYNOPTIC LOW LEVEL
MOISTURE WILL KEEP THE CRYSTAL GROWTH AREA RICH ENOUGH FOR MODEST
ACCUMULATIONS ESPECIALLY EAST OF LAKE ONTARIO. WE WILL HAVE TO KEEP
AN EYE ON THIS. AMOUNTS OFF LAKE ERIE SHOULD BE LIMITED BY THE GREATLY
INCREASED ICE COVER THAT DEVELOPED DURING OUR RECENT ARCTIC BLAST.
ACTIVITY WILL LIKELY BECOME MULTIBANDED MONDAY NIGHT AS WINDS VEER
TO NORTHWEST. THE MULTIBANDED NATURE WITH THIS TYPE OF FLOW ALONG
WITH ONLY MODEST INSTABILITY SHOULD LEAD TO RATHER MINOR AMOUNTS
MONDAY NIGHT.
TEMPERATUREWISE...ALTHOUGH IT WILL BE QUITE COLD AT LEAST IT WILL
NOT BE AS COLD AS OUR RECENT ARCTIC AIRMASS. 850 MB TEMPERATURES
WILL LIKELY ONLY DROP TO MINUS 16C. THIS COMPARES TO MINUS 25C THAT
WE SAW LAST FRIDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
THERE REMAIN DIFFERENCES IN THE LATEST RUN OF THE GFS AND THE
ECMWF...MAINLY ON THE SYSTEM PROGGED TO MOVE THROUGH LATE IN THE
WEEK. AS WITH THE DAY SHIFT YESTERDAY WE WILL CONTINUE CLOSER TO THE
ECMWF SOLUTION.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
MAINLY LIGHT SNOW WILL CONTINUE ACROSS THE AREA THIS MORNING AND
EVENING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER LAKE HURON. CEILINGS WILL BE MAINLY MVFR THROUGH THIS
EVENING WITH PERIODS OF IFR VSBYS. EXPECT LOWER CEILINGS BORDERING
MVFR AND IFR THIS EVENING AND TONIGHT ALONG THE EASTERN SHORE OF
LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH PERIODS OF IFR VSBY IN
SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
WINDS WILL WEAKEN AND TURN MORE WESTERLY TO SOUTHWESTERLY AS A
WEAKENING AREA OF LOW PRESSURE OVER SLOWLY DRIFTS EASTWARD ACROSS
THE LOWER LAKES REGION. A RELATIVELY WEAK TO MODERATE PRESSURE
GRADIENT WILL THEN PERSIST THROUGH MONDAY AND TUESDAY...AND THIS
WILL RESULT IN WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA
INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...TMA
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TMA/WCH
MARINE...JJR/SAGE
000
FXUS61 KBUF 181735
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1235 PM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NORTH OF LAKE ERIE THIS MORNING IS FORECAST TO
TRACK VERY SLOWLY TO LAKE ONTARIO BY MONDAY MORNING WHILE A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. A NORTHWEST FLOW ON
THE BACK SIDE OF THIS COMPLEX SYSTEM WILL BRING A FRESH SUPPLY OF
COLDER THAN NORMAL AIR TO THE REGION THROUGH THE FIRST PART OF THE
WEEK BUT NOT AS COLD AS OUR RECENT ARCTIC BLAST. SOMEWHAT MILDER AIR
IS EXPECTED TO MOVE IN DURING MID TO LATE WEEK WITH ANOTHER ARCTIC
AIR MASS SCHEDULED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK ISENTROPIC UPGLIDE ACROSS THE AREA THIS MORNING MAINTAINING A
STEADY LIGHT SNOWFALL. WEAK SURFACE LOW OVER LAKE HURON LATE THIS
MORNING WILL DRIFT SLOWLY EASTWARD THIS AFTERNOON WITH WEAK WARM AIR
ADVECTION CONTINUING...WHICH SHOULD MAINTAIN THE LIGHT SNOWS ACROSS
THE AREA. THIS SNOW MAY BE ENHANCED DURING THE AFTERNOON BY THE
APPROACH OF AN UPPER SHORTWAVE SEEN LIFTING NORTHEAST THROUGH
EASTERN OHIO/WESTERN PENNSYLVANIA. ADDITIONAL ACCUMULATIONS THIS
AFTERNOON WILL BE ON THE LIGHTER SIDE AND PROBABLY NO MORE THAN 1 TO
3 INCHES...THIS WILL BRING MOST 18 TO 24 HOUR ACCUMULATIONS IN THE 3
TO 6 INCH RANGE. WE WILL MAINTAIN THE WINTER WEATHER ADVISORY UNTIL
4 PM TO ACCOUNT FOR THE SECONDARY AREA OF SNOW WHICH WILL LIFT
ACROSS THE AREA BETWEEN 17Z AND 21Z.
THE INFLUX OF COLDER AIR ON SOUTHWESTERLY FLOW BEHIND COLD FRONT
WILL BRING THE LIKELIHOOD OF SOME LAKE SNOW OFF LAKE ERIE DURING THE
EVENING LASTING INTO THE NIGHT. THE DEPTH OF THE LAKE INDUCED LIFT
WILL BE LIMITED BY AN ISOTHERMAL LAYER FROM 7KFT TO 12KFT AS SHOWN
ON BUFKIT FORECAST SOUNDINGS...BUT THERE COULD BE A FEW INCHES OF
LAKE SNOW IN ADDITION TO THE SYNOPTIC SNOWFALL BEFORE MID LEVEL
SHEAR BREAKS THE BAND UP INTO A MORE BROAD ARE OF LAKE SNOW OVER THE
SOUTHERN TIER LATE TONIGHT. ANOTHER AREA OF LAKE SNOW WILL SET UP ON
LAKE ONTARIO AS THE SURFACE LOW FILLS AND BECOMES A TROUGH ALONG THE
EASTERN LAKE BASIN. AGAIN...NAM 1000-850MB OMEGA SHOWS A BAND ALONG
THE SOUTH HALF OF LAKE ONTARIO DIRECTED TOWARD OSWEGO COUNTY AND THE
SOUTHERN TUG HILL DEVELOPING AROUND 09Z AND MAINTAINING INTO MONDAY
MORNING.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
A MODEST MODEL DIFFERENCE BETWEEN THE NAM AND THE GFS MONDAY
MORNING. IN BOTH...THE SLOWED DOWN CLIPPER HANGS BACK AS THE PARENT
UPPER LOW CLOSES OFF OVER LAKE ONTARIO BUT THE GFS KEEPS A STRONGER
SURFACE REFLECTION THAN THE NAM OVER WESTERN LAKE ONTARIO AS A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. IN BOTH SOLUTIONS
HOWEVER...CONDITIONS LOOK UNSTABLE ENOUGH WITH WESTERLY STEERING
WINDS FOR LAKE EFFECT ACTIVITY EAST OF BOTH LAKES. IT IS NOT NEARLY
AS UNSTABLE AS OUR RECENT EVENT BUT LEFTOVER SYNOPTIC LOW LEVEL
MOISTURE WILL KEEP THE CRYSTAL GROWTH AREA RICH ENOUGH FOR MODEST
ACCUMULATIONS ESPECIALLY EAST OF LAKE ONTARIO. WE WILL HAVE TO KEEP
AN EYE ON THIS. AMOUNTS OFF LAKE ERIE SHOULD BE LIMITED BY THE GREATLY
INCREASED ICE COVER THAT DEVELOPED DURING OUR RECENT ARCTIC BLAST.
ACTIVITY WILL LIKELY BECOME MULTIBANDED MONDAY NIGHT AS WINDS VEER
TO NORTHWEST. THE MULTIBANDED NATURE WITH THIS TYPE OF FLOW ALONG
WITH ONLY MODEST INSTABILITY SHOULD LEAD TO RATHER MINOR AMOUNTS
MONDAY NIGHT.
TEMPERATUREWISE...ALTHOUGH IT WILL BE QUITE COLD AT LEAST IT WILL
NOT BE AS COLD AS OUR RECENT ARCTIC AIRMASS. 850 MB TEMPERATURES
WILL LIKELY ONLY DROP TO MINUS 16C. THIS COMPARES TO MINUS 25C THAT
WE SAW LAST FRIDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
THERE REMAIN DIFFERENCES IN THE LATEST RUN OF THE GFS AND THE
ECMWF...MAINLY ON THE SYSTEM PROGGED TO MOVE THROUGH LATE IN THE
WEEK. AS WITH THE DAY SHIFT YESTERDAY WE WILL CONTINUE CLOSER TO THE
ECMWF SOLUTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MAINLY LIGHT SNOW WILL CONTINUE ACROSS THE AREA THIS MORNING AND
EVENING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER LAKE HURON. CEILINGS WILL BE MAINLY MVFR THROUGH THIS
EVENING WITH PERIODS OF IFR VSBYS. EXPECT LOWER CEILINGS BORDERING
MVFR AND IFR THIS EVENING AND TONIGHT ALONG THE EASTERN SHORE OF
LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH PERIODS OF IFR VSBY IN
SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY AND FRIDAY...MVFR IN SCATTERED SNOW SHOWERS.
&&
.MARINE...
WINDS WILL WEAKEN AND TURN MORE WESTERLY TO SOUTHWESTERLY AS A
WEAKENING AREA OF LOW PRESSURE OVER SLOWLY DRIFTS EASTWARD ACROSS
THE LOWER LAKES REGION. A RELATIVELY WEAK TO MODERATE PRESSURE
GRADIENT WILL THEN PERSIST THROUGH MONDAY AND TUESDAY...AND THIS
WILL RESULT IN WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA
INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...TMA/WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TMA/WCH
MARINE...JJR/SAGE
000
FXUS61 KBUF 181621
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1121 AM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NORTH OF LAKE ERIE THIS MORNING IS FORECAST TO
TRACK VERY SLOWLY TO LAKE ONTARIO BY MONDAY MORNING WHILE A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. A NORTHWEST FLOW ON
THE BACK SIDE OF THIS COMPLEX SYSTEM WILL BRING A FRESH SUPPLY OF
COLDER THAN NORMAL AIR TO THE REGION THROUGH THE FIRST PART OF THE
WEEK BUT NOT AS COLD AS OUR RECENT ARCTIC BLAST. SOMEWHAT MILDER AIR
IS EXPECTED TO MOVE IN DURING MID TO LATE WEEK WITH ANOTHER ARCTIC
AIR MASS SCHEDULED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK ISENTROPIC UPGLIDE ACROSS THE AREA THIS MORNING MAINTAINING A
STEADY LIGHT SNOWFALL. WEAK SURFACE LOW OVER LAKE HURON LATE THIS
MORNING WILL DRIFT SLOWLY EASTWARD THIS AFTERNOON WITH WEAK WARM AIR
ADVECTION CONTINUING...WHICH SHOULD MAINTAIN THE LIGHT SNOWS ACROSS
THE AREA. THIS SNOW MAY BE ENHANCED DURING THE AFTERNOON BY THE
APPROACH OF AN UPPER SHORTWAVE SEEN LIFTING NORTHEAST THROUGH
EASTERN OHIO/WESTERN PENNSYLVANIA. ADDITIONAL ACCUMULATIONS THIS
AFTERNOON WILL BE ON THE LIGHTER SIDE AND PROBABLY NO MORE THAN 1 TO
3 INCHES...THIS WILL BRING MOST 18 TO 24 HOUR ACCUMULATIONS IN THE 3
TO 6 INCH RANGE. WE WILL MAINTAIN THE WINTER WEATHER ADVISORY UNTIL
4 PM TO ACCOUNT FOR THE SECONDARY AREA OF SNOW WHICH WILL LIFT
ACROSS THE AREA BETWEEN 17Z AND 21Z.
THE INFLUX OF COLDER AIR ON SOUTHWESTERLY FLOW BEHIND COLD FRONT
WILL BRING THE LIKELIHOOD OF SOME LAKE SNOW OFF LAKE ERIE DURING THE
EVENING LASTING INTO THE NIGHT. THE DEPTH OF THE LAKE INDUCED LIFT
WILL BE LIMITED BY AN ISOTHERMAL LAYER FROM 7KFT TO 12KFT AS SHOWN
ON BUFKIT FORECAST SOUNDINGS...BUT THERE COULD BE A FEW INCHES OF
LAKE SNOW IN ADDITION TO THE SYNOPTIC SNOWFALL BEFORE MID LEVEL
SHEAR BREAKS THE BAND UP INTO A MORE BROAD ARE OF LAKE SNOW OVER THE
SOUTHERN TIER LATE TONIGHT. ANOTHER AREA OF LAKE SNOW WILL SET UP ON
LAKE ONTARIO AS THE SURFACE LOW FILLS AND BECOMES A TROUGH ALONG THE
EASTERN LAKE BASIN. AGAIN...NAM 1000-850MB OMEGA SHOWS A BAND ALONG
THE SOUTH HALF OF LAKE ONTARIO DIRECTED TOWARD OSWEGO COUNTY AND THE
SOUTHERN TUG HILL DEVELOPING AROUND 09Z AND MAINTAINING INTO MONDAY
MORNING.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
A MODEST MODEL DIFFERENCE BETWEEN THE NAM AND THE GFS MONDAY
MORNING. IN BOTH...THE SLOWED DOWN CLIPPER HANGS BACK AS THE PARENT
UPPER LOW CLOSES OFF OVER LAKE ONTARIO BUT THE GFS KEEPS A STRONGER
SURFACE REFLECTION THAN THE NAM OVER WESTERN LAKE ONTARIO AS A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. IN BOTH SOLUTIONS
HOWEVER...CONDITIONS LOOK UNSTABLE ENOUGH WITH WESTERLY STEERING
WINDS FOR LAKE EFFECT ACTIVITY EAST OF BOTH LAKES. IT IS NOT NEARLY
AS UNSTABLE AS OUR RECENT EVENT BUT LEFTOVER SYNOPTIC LOW LEVEL
MOISTURE WILL KEEP THE CRYSTAL GROWTH AREA RICH ENOUGH FOR MODEST
ACCUMULATIONS ESPECIALLY EAST OF LAKE ONTARIO. WE WILL HAVE TO KEEP
AN EYE ON THIS. AMOUNTS OFF LAKE ERIE SHOULD BE LIMITED BY THE GREATLY
INCREASED ICE COVER THAT DEVELOPED DURING OUR RECENT ARCTIC BLAST.
ACTIVITY WILL LIKELY BECOME MULTIBANDED MONDAY NIGHT AS WINDS VEER
TO NORTHWEST. THE MULTIBANDED NATURE WITH THIS TYPE OF FLOW ALONG
WITH ONLY MODEST INSTABILITY SHOULD LEAD TO RATHER MINOR AMOUNTS
MONDAY NIGHT.
TEMPERATUREWISE...ALTHOUGH IT WILL BE QUITE COLD AT LEAST IT WILL
NOT BE AS COLD AS OUR RECENT ARCTIC AIRMASS. 850 MB TEMPERATURES
WILL LIKELY ONLY DROP TO MINUS 16C. THIS COMPARES TO MINUS 25C THAT
WE SAW LAST FRIDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
THERE REMAIN DIFFERENCES IN THE LATEST RUN OF THE GFS AND THE
ECMWF...MAINLY ON THE SYSTEM PROGGED TO MOVE THROUGH LATE IN THE
WEEK. AS WITH THE DAY SHIFT YESTERDAY WE WILL CONTINUE CLOSER TO THE
ECMWF SOLUTION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
MAINLY LIGHT SNOW WILL CONTINUE TO SPREAD EAST ACROSS THE AREA EARLY
THIS MORNING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER MICHIGAN. CEILINGS WILL BE MAINLY MVFR TODAY WITH
PERIODS OF IFR VSBYS LATE THIS MORNING THROUGH THE AFTERNOON. EXPECT
LOWER CEILINGS BORDERING MVFR AND IFR THIS EVENING AND TONIGHT ALONG
THE EASTERN SHORE OF LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH
PERIODS OF IFR VSBY IN SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
WINDS WILL WEAKEN AND TURN MORE WESTERLY TO SOUTHWESTERLY AS A
WEAKENING AREA OF LOW PRESSURE OVER SLOWLY DRIFTS EASTWARD ACROSS
THE LOWER LAKES REGION. A RELATIVELY WEAK TO MODERATE PRESSURE
GRADIENT WILL THEN PERSIST THROUGH MONDAY AND TUESDAY...AND THIS
WILL RESULT IN WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA
INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...TMA/WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TJP/WCH
MARINE...JJR/SAGE
000
FXUS61 KBUF 181153
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
653 AM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NORTH OF LAKE ERIE THIS MORNING IS FORECAST TO
TRACK VERY SLOWLY TO LAKE ONTARIO BY MONDAY MORNING WHILE A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. A NORTHWEST FLOW ON
THE BACK SIDE OF THIS COMPLEX SYSTEM WILL BRING A FRESH SUPPLY OF
COLDER THAN NORMAL AIR TO THE REGION THROUGH THE FIRST PART OF THE
WEEK BUT NOT AS COLD AS OUR RECENT ARCTIC BLAST. SOMEWHAT MILDER AIR
IS EXPECTED TO MOVE IN DURING MID TO LATE WEEK WITH ANOTHER ARCTIC
AIR MASS SCHEDULED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE OVER THE CENTRAL GREAT LAKES WILL SLOWLY MOVE TO THE
EAST THROUGH THE DAY AND MAINTAIN A GENERAL SNOWFALL ACROSS THE
REGION. THE REGION OF 850MB WARM ADVECTION FORCING HAS SHIFTED TO
THE NORTH AND EAST OF THE AREA DURING THE OVERNIGHT...BUT A SECOND
AREA OF MODERATE SNOW IS EXPECTED THROUGH THE REST OF TODAY AS COLD
FRONT MOVES THROUGH. TEMPS HAVE BEEN WARMING THROUGH THE EARLY
MORNING HOURS AND SHOULD CONTINUE TO MODERATE TO THE UPPER 20S TO
NEAR 30 DEGREES UNTIL MID DAY...THEN FALL DURING THE AFTERNOON AS
THE FRONT MOVES THROUGH. TEMPS TONIGHT SHOULD SETTLE BACK TO THE LOW
TO MID TEENS...WITH UPPER TEENS TO NEAR 20 TO THE SOUTHEAST OF LAKE
ONTARIO.
THIS WILL BRING ANOTHER ROUND OF SNOW WHICH IS PICKED UP WELL IN THE
NAM AND GFS QPF FIELDS. 850MB TEMPS OF AROUND -9C THIS MORNING WILL
FALL TO AROUND -14C ON SOUTHWESTERLY WINDS WITH AN AREA OF UVV
SHOWING ON THE 1000-850MB OMEGA ALONG THE FRONT. EXPECT A BAND OF
SNOW TO MOVE THROUGH THE WESTERN COUNTIES BETWEEN 15Z-21Z AND FROM
THE FINGER LAKES TO THE NORTH COUNTRY FROM 21Z-03Z. QPF FIELDS MATCH
UP WITH THIS FRONT AND WE COULD SEE ANOTHER 2 TO 4 INCHES OF SNOW
WEST OF THE GENESEE VALLEY. THE FINGER LAKES REGION APPEARS TO BE
DRY SLOTTED ON BOTH GFS AND NAM...THUS IT APPEARS THAT MUCH OF THE
SNOWFALL WILL BE LACKING IN THIS AREA.
THE INFLUX OF COLDER AIR ON SOUTHWESTERLY FLOW WILL ALSO BRING THE
LIKELIHOOD OF SOME LAKE SNOW OFF LAKE ERIE DURING THE EVENING
LASTING INTO THE NIGHT. THE DEPTH OF THE LAKE INDUCED LIFT WILL BE
LIMITED BY AN ISOTHERMAL LAYER FROM 7KFT TO 12KFT AS SHOWN ON BUFKIT
FORECAST SOUNDINGS...BUT THERE COULD BE A FEW INCHES OF LAKE SNOW IN
ADDITION TO THE SYNOPTIC SNOWFALL BEFORE MID LEVEL SHEAR BREAKS THE
BAND UP INTO A MORE BROAD ARE OF LAKE SNOW OVER THE SOUTHERN TIER
LATE TONIGHT. ANOTHER AREA OF LAKE SNOW WILL SET UP ON LAKE ONTARIO
AS THE SURFACE LOW FILLS AND BECOMES A TROUGH ALONG THE EASTERN LAKE
BASIN. AGAIN...NAM 1000-850MB OMEGA SHOWS A BAND ALONG THE SOUTH
HALF OF LAKE ONTARIO DIRECTED TOWARD OSWEGO COUNTY AND THE SOUTHERN
TUG HILL DEVELOPING AROUND 09Z AND MAINTAINING INTO MONDAY MORNING.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
A MODEST MODEL DIFFERENCE BETWEEN THE NAM AND THE GFS MONDAY
MORNING. IN BOTH...THE SLOWED DOWN CLIPPER HANGS BACK AS THE PARENT
UPPER LOW CLOSES OFF OVER LAKE ONTARIO BUT THE GFS KEEPS A STRONGER
SURFACE REFLECTION THAN THE NAM OVER WESTERN LAKE ONTARIO AS A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. IN BOTH SOLUTIONS
HOWEVER...CONDITIONS LOOK UNSTABLE ENOUGH WITH WESTERLY STEERING
WINDS FOR LAKE EFFECT ACTIVITY EAST OF BOTH LAKES. IT IS NOT NEARLY
AS UNSTABLE AS OUR RECENT EVENT BUT LEFTOVER SYNOPTIC LOW LEVEL
MOISTURE WILL KEEP THE CRYSTAL GROWTH AREA RICH ENOUGH FOR MODEST
ACCUMULATIONS ESPECIALLY EAST OF LAKE ONTARIO. WE WILL HAVE TO KEEP
AN EYE ON THIS. AMOUNTS OFF LAKE ERIE SHOULD BE LIMITED BY THE GREATLY
INCREASED ICE COVER THAT DEVELOPED DURING OUR RECENT ARCTIC BLAST.
ACTIVITY WILL LIKELY BECOME MULTIBANDED MONDAY NIGHT AS WINDS VEER
TO NORTHWEST. THE MULTIBANDED NATURE WITH THIS TYPE OF FLOW ALONG
WITH ONLY MODEST INSTABILITY SHOULD LEAD TO RATHER MINOR AMOUNTS
MONDAY NIGHT.
TEMPERATUREWISE...ALTHOUGH IT WILL BE QUITE COLD AT LEAST IT WILL
NOT BE AS COLD AS OUR RECENT ARCTIC AIRMASS. 850 MB TEMPERATURES
WILL LIKELY ONLY DROP TO MINUS 16C. THIS COMPARES TO MINUS 25C THAT
WE SAW LAST FRIDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
THERE REMAIN DIFFERENCES IN THE LATEST RUN OF THE GFS AND THE
ECMWF...MAINLY ON THE SYSTEM PROGGED TO MOVE THROUGH LATE IN THE
WEEK. AS WITH THE DAY SHIFT YESTERDAY WE WILL CONTINUE CLOSER TO THE
ECMWF SOLUTION.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MAINLY LIGHT SNOW WILL CONTINUE TO SPREAD EAST ACROSS THE AREA EARLY
THIS MORNING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER MICHIGAN. CEILINGS WILL BE MAINLY MVFR TODAY WITH
PERIODS OF IFR VSBYS LATE THIS MORNING THROUGH THE AFTERNOON. EXPECT
LOWER CEILINGS BORDERING MVFR AND IFR THIS EVENING AND TONIGHT ALONG
THE EASTERN SHORE OF LAKE ERIE AS WEAK LAKE SNOW DEVELOPS WITH
PERIODS OF IFR VSBY IN SNOW...AND MVFR ELSEWHERE.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO THIS
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EASTWARD ACROSS
THE AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
WINDS WILL WEAKEN AND TURN MORE WESTERLY TO SOUTHWESTERLY AS A
WEAKENING AREA OF LOW PRESSURE OVER SLOWLY DRIFTS EASTWARD ACROSS
THE LOWER LAKES REGION. A RELATIVELY WEAK TO MODERATE PRESSURE
GRADIENT WILL THEN PERSIST THROUGH MONDAY AND TUESDAY...AND THIS
WILL RESULT IN WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA
INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TJP/WCH
MARINE...JJR/SAGE
000
FXUS61 KBUF 180856
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
356 AM EST SUN JAN 18 2009
.SYNOPSIS...
LOW PRESSURE CENTERED NORTH OF LAKE ERIE THIS MORNING IS FORECAST TO
TRACK VERY SLOWLY TO LAKE ONTARIO BY MONDAY MORNING WHILE A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. A NORTHWEST FLOW ON
THE BACK SIDE OF THIS COMPLEX SYSTEM WILL BRING A FRESH SUPPLY OF
COLDER THAN NORMAL AIR TO THE REGION THROUGH THE FIRST PART OF THE
WEEK BUT NOT AS COLD AS OUR RECENT ARCTIC BLAST. SOMEWHAT MILDER AIR
IS EXPECTED TO MOVE IN DURING MID TO LATE WEEK WITH ANOTHER ARCTIC
AIR MASS SCHEDULED FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW PRESSURE OVER THE CENTRAL GREAT LAKES WILL SLOWLY MOVE TO THE
EAST THROUGH THE DAY AND MAINTAIN A GENERAL SNOWFALL ACROSS THE
REGION. THE REGION OF 850MB WARM ADVECTION FORCING HAS SHIFTED TO
THE NORTH AND EAST OF THE AREA DURING THE OVERNIGHT...BUT A SECOND
AREA OF MODERATE SNOW IS EXPECTED THROUGH THE REST OF TODAY AS COLD
FRONT MOVES THROUGH. TEMPS HAVE BEEN WARMING THROUGH THE EARLY
MORNING HOURS AND SHOULD CONTINUE TO MODERATE TO THE UPPER 20S TO
NEAR 30 DEGREES UNTIL MID DAY...THEN FALL DURING THE AFTERNOON AS
THE FRONT MOVES THROUGH. TEMPS TONIGHT SHOULD SETTLE BACK TO THE LOW
TO MID TEENS...WITH UPPER TEENS TO NEAR 20 TO THE SOUTHEAST OF LAKE
ONTARIO.
THIS WILL BRING ANOTHER ROUND OF SNOW WHICH IS PICKED UP WELL IN THE
NAM AND GFS QPF FIELDS. 850MB TEMPS OF AROUND -9C THIS MORNING WILL
FALL TO AROUND -14C ON SOUTHWESTERLY WINDS WITH AN AREA OF UVV
SHOWING ON THE 1000-850MB OMEGA ALONG THE FRONT. EXPECT A BAND OF
SNOW TO MOVE THROUGH THE WESTERN COUNTIES BETWEEN 15Z-21Z AND FROM
THE FINGER LAKES TO THE NORTH COUNTRY FROM 21Z-03Z. QPF FIELDS MATCH
UP WITH THIS FRONT AND WE COULD SEE ANOTHER 2 TO 4 INCHES OF SNOW
WEST OF THE GENESEE VALLEY. THE FINGER LAKES REGION APPEARS TO BE
DRY SLOTTED ON BOTH GFS AND NAM...THUS IT APPEARS THAT MUCH OF THE
SNOWFALL WILL BE LACKING IN THIS AREA.
THE INFLUX OF COLDER AIR ON SOUTHWESTERLY FLOW WILL ALSO BRING THE
LIKELIHOOD OF SOME LAKE SNOW OFF LAKE ERIE DURING THE EVENING
LASTING INTO THE NIGHT. THE DEPTH OF THE LAKE INDUCED LIFT WILL BE
LIMITED BY AN ISOTHERMAL LAYER FROM 7KFT TO 12KFT AS SHOWN ON BUFKIT
FORECAST SOUNDINGS...BUT THERE COULD BE A FEW INCHES OF LAKE SNOW IN
ADDITION TO THE SYNOPTIC SNOWFALL BEFORE MID LEVEL SHEAR BREAKS THE
BAND UP INTO A MORE BROAD ARE OF LAKE SNOW OVER THE SOUTHERN TIER
LATE TONIGHT. ANOTHER AREA OF LAKE SNOW WILL SET UP ON LAKE ONTARIO
AS THE SURFACE LOW FILLS AND BECOMES A TROUGH ALONG THE EASTERN LAKE
BASIN. AGAIN...NAM 1000-850MB OMEGA SHOWS A BAND ALONG THE SOUTH
HALF OF LAKE ONTARIO DIRECTED TOWARD OSWEGO COUNTY AND THE SOUTHERN
TUG HILL DEVELOPING AROUND 09Z AND MAINTAINING INTO MONDAY MORNING.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
A MODEST MODEL DIFFERENCE BETWEEN THE NAM AND THE GFS MONDAY
MORNING. IN BOTH...THE SLOWED DOWN CLIPPER HANGS BACK AS THE PARENT
UPPER LOW CLOSES OFF OVER LAKE ONTARIO BUT THE GFS KEEPS A STRONGER
SURFACE REFLECTION THAN THE NAM OVER WESTERN LAKE ONTARIO AS A
SECONDARY LOW DEEPENS OFF THE NEW ENGLAND COAST. IN BOTH SOLUTIONS
HOWEVER...CONDITIONS LOOK UNSTABLE ENOUGH WITH WESTERLY STEERING
WINDS FOR LAKE EFFECT ACTIVITY EAST OF BOTH LAKES. IT IS NOT NEARLY
AS UNSTABLE AS OUR RECENT EVENT BUT LEFTOVER SYNOPTIC LOW LEVEL
MOISTURE WILL KEEP THE CRYSTAL GROWTH AREA RICH ENOUGH FOR MODEST
ACCUMULATIONS ESPECIALLY EAST OF LAKE ONTARIO. WE WILL HAVE TO KEEP
AN EYE ON THIS. AMOUNTS OFF LAKE ERIE SHOULD BE LIMITED BY THE GREATLY
INCREASED ICE COVER THAT DEVELOPED DURING OUR RECENT ARCTIC BLAST.
ACTIVITY WILL LIKELY BECOME MULTIBANDED MONDAY NIGHT AS WINDS VEER
TO NORTHWEST. THE MULTIBANDED NATURE WITH THIS TYPE OF FLOW ALONG
WITH ONLY MODEST INSTABILITY SHOULD LEAD TO RATHER MINOR AMOUNTS
MONDAY NIGHT.
TEMPERATUREWISE...ALTHOUGH IT WILL BE QUITE COLD AT LEAST IT WILL
NOT BE AS COLD AS OUR RECENT ARCTIC AIRMASS. 850 MB TEMPERATURES
WILL LIKELY ONLY DROP TO MINUS 16C. THIS COMPARES TO MINUS 25C THAT
WE SAW LAST FRIDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
THERE REMAIN DIFFERENCES IN THE LATEST RUN OF THE GFS AND THE
ECMWF...MAINLY ON THE SYSTEM PROGGED TO MOVE THROUGH LATE IN THE
WEEK. AS WITH THE DAY SHIFT YESTERDAY WE WILL CONTINUE CLOSER TO THE
ECMWF SOLUTION.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
MAINLY LIGHT SNOW WILL CONTINUE TO SPREAD EAST ACROSS THE AREA EARLY
THIS MORNING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER MICHIGAN. A JET STREAK THAT IS PUSHING ACROSS NORTHERN
OHIO WILL ENHANCE THE SNOWFALL AT TIMES FROM ABOUT 06Z UNTIL ABOUT
08Z. EXPECT MVFR CIGS TO BE THE RULE...WITH MAINLY IFR CIGS IN -SN.
LATER TONIGHT THROUGH SUNDAY MORNING...LIGHT SNOW AND FOG WILL KEEP
CIGS/VSBYS AT MOSTLY MVFR LEVELS.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO SATURDAY
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EAST ACROSS THE
AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
WINDS WILL WEAKEN AND TURN MORE WESTERLY TO SOUTHWESTERLY AS A
WEAKENING AREA OF LOW PRESSURE OVER SLOWLY DRIFTS EASTWARD ACROSS
THE LOWER LAKES REGION. A RELATIVELY WEAK TO MODERATE PRESSURE
GRADIENT WILL THEN PERSIST THROUGH MONDAY AND TUESDAY...AND THIS
WILL RESULT IN WINDS AND WAVES REMAINING BELOW SMALL CRAFT CRITERIA
INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ001>008-010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...SAGE
NEAR TERM...WCH
SHORT TERM...SAGE
LONG TERM...JJR/SAGE
AVIATION...TJP
MARINE...JJR/SAGE
000
FXUS61 KBUF 180451
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1151 PM EST SAT JAN 17 2009
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL DRIFT EAST INTO
SOUTHERN ONTARIO TONIGHT AND SUNDAY...AND WILL BRING BOTH A GENERAL
SNOWFALL AND A RETURN TO MORE NORMAL MIDWINTER TEMPERATURES. THE LOW
WILL THEN SLOWLY WEAKEN IN PLACE OVER THE AREA SUNDAY NIGHT THROUGH
TUESDAY...WHILE KEEPING A GENERAL CHANCE OF SNOW SHOWERS ACROSS THE
REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST SURFACE MAP SHOWS THE SURFACE LOW CENTERED JUST EAST OF
LAKE ONTARIO THIS EVENING WITH AN OCCLUDED FRONT TRAILING SOUTH
ACROSS EASTERN INDIANA. STRONG WARM AIR ADVECTION ON THE NOSE OF A
40 TO 50 KNOT LOW LEVEL JET IS GENERATING AN AREA OF STEADY SNOW
AHEAD OF THE APPROACHING LOW. THE LEADING EDGE OF THIS STEADIER SNOW
IS BEGINNING TO WORK INTO FAR WESTERN NEW YORK AND WILL CONTINUE TO
SPREAD EAST ACROSS THE REST OF THE AREA THIS EVENING AS THE LOW
LEVEL JET TRACKS TO THE EAST.
THE LATEST IR SATELLITE IMAGE SHOWS THE COLDEST CLOUD TOPS CENTERED
BETWEEN LONDON AND HAMILTON ONTARIO. THESE COLDER TOPS ARE
ASSOCIATED WITH LFQ OF AN UPPER LEVEL JET STREAK THAT IS PUSHING
ACROSS OHIO. AS THIS AREA OF ENHANCED UPWARD MOTION TRACKS EAST
ACROSS SOUTHERN ONTARIO AND FAR WESTERN NEW YORK...A PERIOD OF
MODERATE SNOW MAY DEVELOP BEFORE MIDNIGHT ACROSS PARTS OF THE
NIAGARA FRONTIER.
THE FAVORABLE LOW LEVEL AND UPPER LEVEL LIFTING MECHANISMS WILL
COMBINE WITH A PRIME DENDRITIC GROWTH REGION FROM ABOUT 3K TO 10K
FEET. THESE PARAMETERS SEEM TO MATCH UP BEST TONIGHT WHICH WILL
LIKELY RESULT IN PERIODS OF MODERATE TO HEAVY SNOW.
ON SUNDAY...THE MOST FAVORABLE LIFT ASSOCIATED WITH THE WARM AIR
ADVECTION PATTERN WILL SLIDE OFF TO OUR EAST DURING THE MORNING.
THIS MAY LEAD TO A BREAK IN THE STEADY ACROSS WESTERN NEW YORK AND
THE GENESEE VALLEY...BUT ANOTHER BURST OF SNOW IS POSSIBLE DURING
THE AFTERNOON AS THE OCCLUDED FRONT WORKS EAST ACROSS THE AREA.
ADDITIONAL LIFT WILL BE GENERATED BY THE UPPER LEVEL SHORT WAVE THAT
IS PUSHING THROUGH MICHIGAN THIS EVENING.
THERMAL PROFILES WOULD SUGGEST A SNOW-WATER RATIO OF AROUND 20:1
TONIGHT...BEFORE DROPPING BACK TO SOMETHING CLOSER TO 15:1 FOR
SUNDAY AS TEMPERATURES WARM. SOME MODEL BLEND COMBINED WITH HPC QPF
LOOK TO HANDLE EXPECTED PRECIPITATION SUFFICIENTLY AND GENERATES A
GENERAL 3 TO 6 INCH ACCUMULATION FOR THE AREA...WITH ISOLATED
HEAVIER AMOUNTS NOT OUT OF THE QUESTION. THEREFORE...THE ENTIRE AREA
WILL REMAIN IN A WINTER WEATHER ADVISORY FROM TONIGHT THROUGH SUNDAY
AFTERNOON WITH THE STARTING TIMES SKEWED SLIGHTLY FROM WEST TO EAST.
WARM AIR ADVECTION AHEAD OF THE APPROACHING LOW WILL ALLOW
TEMPERATURES TO SLOWLY MODERATE FROM WEST TO EAST TONIGHT THROUGH
SUNDAY MORNING. SOME LOCATIONS MAY SEE READINGS APPROACHING THE
FREEZING MARK FOR HIGHS ON SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE CLIPPER SYSTEM RESPONSIBLE FOR
TONIGHT AND SUNDAY`S WIDESPREAD SNOWFALL WILL SLOWLY DRIFT EAST AND
WEAKEN INTO AN INVERTED TROUGH...AS ITS ENERGY TRANSFERS TO A
SECONDARY LOW DEVELOPING AND LIFTING NORTHEAST ALONG THE MID
ATLANTIC AND NEW ENGLAND COASTS.
WHILE THE STEADIEST AND HEAVIEST PRECIP ASSOCIATED WITH THE DECAYING
CLIPPER WILL BE ALREADY BE OVER WITH BY THE START OF THE PERIOD...
OUR AIRMASS WILL STILL BE COLD ENOUGH ALOFT...AND THE SYSTEM WILL
STILL HAVE ENOUGH LEFTOVER ENERGY TO KEEP A DECENT CHANCE OF SOME
PRECIP INTACT ACROSS THE ENTIRE AREA THOUGH MONDAY NIGHT. POPS
THROUGH THIS TIME FRAME WILL THUS GENERALLY RANGE FROM MID TO HIGH
CHANCE TO THE LOW LIKELY RANGE...WITH THE HIGHEST VALUES RESERVED
FOR AREAS ALONG AND EAST OF THE SURFACE OCCLUSION SUNDAY NIGHT...AND
THE ENTIRE AREA MONDAY MORNING AS THE SUPPORTING MID-LEVEL
LOW/DEFORMATION ZONE SLIDES EAST ACROSS NEW YORK STATE.
QPF FROM THE SHORT TERM GUIDANCE AND HPC IS GENERALLY LIGHT THROUGH
THE PERIOD...INDICATING THE POTENTIAL FOR 1-2 INCHES OF NUISANCE
SNOWFALL ACCUMULATIONS ACROSS THE BULK OF THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
IN GENERAL...HAVE OPTED TO FOLLOW THE MORE CONSISTENT ECMWF AND HPC
GUIDANCE WHEN PREPARING THE EXTENDED FORECAST...RATHER THAN THE GFS
WHICH HAS RECENTLY SHOWN A LOT OF RUN-TO-RUN INCONSISTENCY IN THE
TIMING AND STRENGTH OF THE LOW PROGGED TO AFFECT THE AREA LATE IN
THE WEEK. ALSO...GIVEN THE -20C OR COLDER 850 MB TEMPS PROJECTED BY
BOTH MODELS FOR NEXT WEEKEND...HAVE OPTED TO UNDERCUT MEX/HPC
GUIDANCE TEMPS FOR FRIDAY NIGHT AND SATURDAY...AS THESE APPEAR TO BE
TOO WARM.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MAINLY LIGHT SNOW WILL CONTINUE TO SPREAD EAST ACROSS THE AREA EARLY
THIS MORNING AS WARM AIR ADVECTION CONTINUES EAST OF LOW PRESSURE
CENTERED OVER MICHIGAN. A JET STREAK THAT IS PUSHING ACROSS NORTHERN
OHIO WILL ENHANCE THE SNOWFALL AT TIMES FROM ABOUT 06Z UNTIL ABOUT
08Z. EXPECT MVFR CIGS TO BE THE RULE...WITH MAINLY IFR CIGS IN -SN.
LATER TONIGHT THROUGH SUNDAY MORNING...LIGHT SNOW AND FOG WILL KEEP
CIGS/VSBYS AT MOSTLY MVFR LEVELS.
AS THE SURFACE LOW TRACKS JUST NORTH OF LAKE ONTARIO SATURDAY
AFTERNOON...IT WILL DRAG A TRAILING OCCLUDED FRONT EAST ACROSS THE
AREA. A BURST OF SNOW IS POSSIBLE WITH THE FRONTAL PASSAGE. LOW
LEVEL MOISTURE LINGERING BEHIND THE DEPARTING LOW AND OCCLUDED FRONT
WILL MAINTAIN MVFR CONDITIONS THROUGH SUNDAY NIGHT.
MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
MODEST SOUTHERLY WINDS WILL FRESHEN A BIT AND TURN MORE
SOUTHEASTERLY TONIGHT...THOUGH THE OFFSHORE FLOW WILL DIRECT THE
HIGHER WAVES AWAY FROM THE SOUTHERN AND EASTERN SHORES OF LAKE
ONTARIO...SO NO SMALL CRAFT ADVISORIES WILL BE NECESSARY.
ON SUNDAY AND SUNDAY NIGHT...WINDS WILL WEAKEN AND TURN MORE
WESTERLY TO SOUTHWESTERLY AS A WEAKENING AREA OF LOW PRESSURE OVER
SLOWLY DRIFTS EASTWARD ACROSS SOUTHERN ONTARIO. A RELATIVELY WEAK TO
MODERATE PRESSURE GRADIENT WILL THEN PERSIST THROUGH MONDAY AND
TUESDAY...AND THIS WILL RESULT IN WINDS AND WAVES REMAINING BELOW
SMALL CRAFT CRITERIA INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ001>008-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TJP/TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TJP
MARINE...JJR
000
FXUS61 KBUF 180235
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
935 PM EST SAT JAN 17 2009
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL DRIFT EAST INTO
SOUTHERN ONTARIO TONIGHT AND SUNDAY...AND WILL BRING BOTH A GENERAL
SNOWFALL AND A RETURN TO MORE NORMAL MIDWINTER TEMPERATURES. THE LOW
WILL THEN SLOWLY WEAKEN IN PLACE OVER THE AREA SUNDAY NIGHT THROUGH
TUESDAY...WHILE KEEPING A GENERAL CHANCE OF SNOW SHOWERS ACROSS THE
REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST SURFACE MAP SHOWS THE SURFACE LOW CENTERED JUST EAST OF
LAKE ONTARIO THIS EVENING WITH AN OCCLUDED FRONT TRAILING SOUTH
ACROSS EASTERN INDIANA. STRONG WARM AIR ADVECTION ON THE NOSE OF A
40 TO 50 KNOT LOW LEVEL JET IS GENERATING AN AREA OF STEADY SNOW
AHEAD OF THE APPROACHING LOW. THE LEADING EDGE OF THIS STEADIER SNOW
IS BEGINNING TO WORK INTO FAR WESTERN NEW YORK AND WILL CONTINUE TO
SPREAD EAST ACROSS THE REST OF THE AREA THIS EVENING AS THE LOW
LEVEL JET TRACKS TO THE EAST.
THE LATEST IR SATELLITE IMAGE SHOWS THE COLDEST CLOUD TOPS CENTERED
BETWEEN LONDON AND HAMILTON ONTARIO. THESE COLDER TOPS ARE
ASSOCIATED WITH LFQ OF AN UPPER LEVEL JET STREAK THAT IS PUSHING
ACROSS OHIO. AS THIS AREA OF ENHANCED UPWARD MOTION TRACKS EAST
ACROSS SOUTHERN ONTARIO AND FAR WESTERN NEW YORK...A PERIOD OF
MODERATE SNOW MAY DEVELOP BEFORE MIDNIGHT ACROSS PARTS OF THE
NIAGARA FRONTIER.
THE FAVORABLE LOW LEVEL AND UPPER LEVEL LIFTING MECHANISMS WILL
COMBINE WITH A PRIME DENDRITIC GROWTH REGION FROM ABOUT 3K TO 10K
FEET. THESE PARAMETERS SEEM TO MATCH UP BEST TONIGHT WHICH WILL
LIKELY RESULT IN PERIODS OF MODERATE TO HEAVY SNOW.
ON SUNDAY...THE MOST FAVORABLE LIFT ASSOCIATED WITH THE WARM AIR
ADVECTION PATTERN WILL SLIDE OFF TO OUR EAST DURING THE MORNING.
THIS MAY LEAD TO A BREAK IN THE STEADY ACROSS WESTERN NEW YORK AND
THE GENESEE VALLEY...BUT ANOTHER BURST OF SNOW IS POSSIBLE DURING
THE AFTERNOON AS THE OCCLUDED FRONT WORKS EAST ACROSS THE AREA.
ADDITIONAL LIFT WILL BE GENERATED BY THE UPPER LEVEL SHORT WAVE THAT
IS PUSHING THROUGH MICHIGAN THIS EVENING.
THERMAL PROFILES WOULD SUGGEST A SNOW-WATER RATIO OF AROUND 20:1
TONIGHT...BEFORE DROPPING BACK TO SOMETHING CLOSER TO 15:1 FOR
SUNDAY AS TEMPERATURES WARM. SOME MODEL BLEND COMBINED WITH HPC QPF
LOOK TO HANDLE EXPECTED PRECIPITATION SUFFICIENTLY AND GENERATES A
GENERAL 3 TO 6 INCH ACCUMULATION FOR THE AREA...WITH ISOLATED
HEAVIER AMOUNTS NOT OUT OF THE QUESTION. THEREFORE...THE ENTIRE AREA
WILL REMAIN IN A WINTER WEATHER ADVISORY FROM TONIGHT THROUGH SUNDAY
AFTERNOON WITH THE STARTING TIMES SKEWED SLIGHTLY FROM WEST TO EAST.
WARM AIR ADVECTION AHEAD OF THE APPROACHING LOW WILL ALLOW
TEMPERATURES TO SLOWLY MODERATE FROM WEST TO EAST TONIGHT THROUGH
SUNDAY MORNING. SOME LOCATIONS MAY SEE READINGS APPROACHING THE
FREEZING MARK FOR HIGHS ON SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE CLIPPER SYSTEM RESPONSIBLE FOR
TONIGHT AND SUNDAY`S WIDESPREAD SNOWFALL WILL SLOWLY DRIFT EAST AND
WEAKEN INTO AN INVERTED TROUGH...AS ITS ENERGY TRANSFERS TO A
SECONDARY LOW DEVELOPING AND LIFTING NORTHEAST ALONG THE MID
ATLANTIC AND NEW ENGLAND COASTS.
WHILE THE STEADIEST AND HEAVIEST PRECIP ASSOCIATED WITH THE DECAYING
CLIPPER WILL BE ALREADY BE OVER WITH BY THE START OF THE PERIOD...
OUR AIRMASS WILL STILL BE COLD ENOUGH ALOFT...AND THE SYSTEM WILL
STILL HAVE ENOUGH LEFTOVER ENERGY TO KEEP A DECENT CHANCE OF SOME
PRECIP INTACT ACROSS THE ENTIRE AREA THOUGH MONDAY NIGHT. POPS
THROUGH THIS TIME FRAME WILL THUS GENERALLY RANGE FROM MID TO HIGH
CHANCE TO THE LOW LIKELY RANGE...WITH THE HIGHEST VALUES RESERVED
FOR AREAS ALONG AND EAST OF THE SURFACE OCCLUSION SUNDAY NIGHT...AND
THE ENTIRE AREA MONDAY MORNING AS THE SUPPORTING MID-LEVEL
LOW/DEFORMATION ZONE SLIDES EAST ACROSS NEW YORK STATE.
QPF FROM THE SHORT TERM GUIDANCE AND HPC IS GENERALLY LIGHT THROUGH
THE PERIOD...INDICATING THE POTENTIAL FOR 1-2 INCHES OF NUISANCE
SNOWFALL ACCUMULATIONS ACROSS THE BULK OF THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
IN GENERAL...HAVE OPTED TO FOLLOW THE MORE CONSISTENT ECMWF AND HPC
GUIDANCE WHEN PREPARING THE EXTENDED FORECAST...RATHER THAN THE GFS
WHICH HAS RECENTLY SHOWN A LOT OF RUN-TO-RUN INCONSISTENCY IN THE
TIMING AND STRENGTH OF THE LOW PROGGED TO AFFECT THE AREA LATE IN
THE WEEK. ALSO...GIVEN THE -20C OR COLDER 850 MB TEMPS PROJECTED BY
BOTH MODELS FOR NEXT WEEKEND...HAVE OPTED TO UNDERCUT MEX/HPC
GUIDANCE TEMPS FOR FRIDAY NIGHT AND SATURDAY...AS THESE APPEAR TO BE
TOO WARM.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE CENTERED OVER LAKE MICHIGAN THIS EVENING WILL MOVE
SLOWLY TO THE EAST TONIGHT AND SUNDAY...STAYING NORTHWEST OF LAKE
ONTARIO THROUGH THE TAF PERIOD. WARM AIR ADVECTION AHEAD OF THIS
SYSTEM AND ADDITIONAL LIFT AHEAD OF AN APPROACHING SHORT WAVE
WILL GENERATE PERIODS OF SNOW TONIGHT THROUGH SUNDAY MORNING.
A FIRST BATCH OF MAINLY LIGHT SNOW THAT IS IMPACTING WESTERN AND
CENTRAL NEW YORK THIS EVENING WILL SLIDE TO THE EAST AS AN
UPPER LEVEL JET STREAK MOVES OFF THE SOUTHERN NEW ENGLAND COAST.
A BETTER ORGANIZED AREA OF SNOW IS DEVELOPING OVER MICHIGAN...DUE TO
STRONGER LOW LEVEL MOISTURE CONVERGENCE IN THE VCNTY OF THE LOW
AND ADDED LIFT GENERATED BY THE WELL DEFINED SHORT WAVE THAT IS
DIVING SOUTHEAST TOWARD MICHIGAN. EXPECT THE STEADIER AREA OF SNOW
TO IMPACT OUR TAF SITES LATER TONIGHT THROUGH SUNDAY MORNING.
THROUGH THIS EVENING...EXPECT MAINLY VFR CIGS WITH VSBYS
OCCASIONALLY LOWERING TO MVFR OR IFR WITH THE LIGHT SNOW THAT IS
PASSING THROUGH THE AREA. UPSTREAM OBSERVATIONS CLOSER TO THE MAIN
CENTER OF THE LAKE MICHIGAN LOW SHOW CIGS VARYING BETWEEN MVFR AND
VFR...WHILE VSBYS ARE MAINLY AT IFR LEVELS. THESE TRENDS WILL MAKE
THE TIMING OF THE LOWER CONDITIONS VERY DIFFICULT TO FORECAST.
EXPECT THE STEADIER SNOW TO TAPER OFF FROM WEST TO EAST SUNDAY
AFTERNOON AS THE OCCLUDED FRONT...TRAILING SOUTH OF THE
AFOREMENTIONED LOW...MOVES EAST ACROSS THE STATE. A BURST OF SNOW IS
POSSIBLE WITH THE FRONTAL PASSAGE. STILL EXPECT MVFR CIGS TO THE
RULE ON SUNDAY...WITH VSBYS VARYING BETWEEN MVFR AND IFR.
SUNDAY NIGHT AND MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
MODEST SOUTHERLY WINDS WILL FRESHEN A BIT AND TURN MORE
SOUTHEASTERLY TONIGHT...THOUGH THE OFFSHORE FLOW WILL DIRECT THE
HIGHER WAVES AWAY FROM THE SOUTHERN AND EASTERN SHORES OF LAKE
ONTARIO...SO NO SMALL CRAFT ADVISORIES WILL BE NECESSARY.
ON SUNDAY AND SUNDAY NIGHT...WINDS WILL WEAKEN AND TURN MORE
WESTERLY TO SOUTHWESTERLY AS A WEAKENING AREA OF LOW PRESSURE OVER
SLOWLY DRIFTS EASTWARD ACROSS SOUTHERN ONTARIO. A RELATIVELY WEAK TO
MODERATE PRESSURE GRADIENT WILL THEN PERSIST THROUGH MONDAY AND
TUESDAY...AND THIS WILL RESULT IN WINDS AND WAVES REMAINING BELOW
SMALL CRAFT CRITERIA INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ001>008-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TJP/TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...TJP
MARINE...JJR
000
FXUS61 KBUF 180158
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
858 PM EST SAT JAN 17 2009
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL DRIFT EAST INTO
SOUTHERN ONTARIO TONIGHT AND SUNDAY...AND WILL BRING BOTH A GENERAL
SNOWFALL AND A RETURN TO MORE NORMAL MIDWINTER TEMPERATURES. THE LOW
WILL THEN SLOWLY WEAKEN IN PLACE OVER THE AREA SUNDAY NIGHT THROUGH
TUESDAY...WHILE KEEPING A GENERAL CHANCE OF SNOW SHOWERS ACROSS THE
REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST SURFACE MAP SHOWS THE SURFACE LOW CENTERED JUST EAST OF
LAKE ONTARIO THIS EVENING WITH AN OCCLUDED FRONT TRAILING SOUTH
ACROSS EASTERN INDIANA. STRONG WARM AIR ADVECTION ON THE NOSE OF A
40 TO 50 KNOT LOW LEVEL JET IS GENERATING AN AREA OF STEADY SNOW
AHEAD OF THE APPROACHING LOW. THE LEADING EDGE OF THIS STEADIER SNOW
IS BEGINNING TO WORK INTO FAR WESTERN NEW YORK AND WILL CONTINUE TO
SPREAD EAST ACROSS THE REST OF THE AREA THIS EVENING AS THE LOW
LEVEL JET TRACKS TO THE EAST.
THE LATEST IR SATELLITE IMAGE SHOWS THE COLDEST CLOUD TOPS CENTERED
BETWEEN LONDON AND HAMILTON ONTARIO. THESE COLDER TOPS ARE
ASSOCIATED WITH LFQ OF AN UPPER LEVEL JET STREAK THAT IS PUSHING
ACROSS OHIO. AS THIS AREA OF ENHANCED UPWARD MOTION TRACKS EAST
ACROSS SOUTHERN ONTARIO AND FAR WESTERN NEW YORK...A PERIOD OF
MODERATE SNOW MAY DEVELOP BEFORE MIDNIGHT ACROSS PARTS OF THE
NIAGARA FRONTIER.
THE FAVORABLE LOW LEVEL AND UPPER LEVEL LIFTING MECHANISMS WILL
COMBINE WITH A PRIME DENDRITIC GROWTH REGION FROM ABOUT 3K TO 10K
FEET. THESE PARAMETERS SEEM TO MATCH UP BEST TONIGHT WHICH WILL
LIKELY RESULT IN PERIODS OF MODERATE TO HEAVY SNOW.
ON SUNDAY...THE MOST FAVORABLE LIFT ASSOCIATED WITH THE WARM AIR
ADVECTION PATTERN WILL SLIDE OFF TO OUR EAST DURING THE MORNING.
THIS MAY LEAD TO A BREAK IN THE STEADY ACROSS WESTERN NEW YORK AND
THE GENESEE VALLEY...BUT ANOTHER BURST OF SNOW IS POSSIBLE DURING
THE AFTERNOON AS THE OCCLUDED FRONT WORKS EAST ACROSS THE AREA.
ADDITIONAL LIFT WILL BE GENERATED BY THE UPPER LEVEL SHORT WAVE THAT
IS PUSHING THROUGH MICHIGAN THIS EVENING.
THERMAL PROFILES WOULD SUGGEST A SNOW-WATER RATIO OF AROUND 20:1
TONIGHT...BEFORE DROPPING BACK TO SOMETHING CLOSER TO 15:1 FOR
SUNDAY AS TEMPERATURES WARM. SOME MODEL BLEND COMBINED WITH HPC QPF
LOOK TO HANDLE EXPECTED PRECIPITATION SUFFICIENTLY AND GENERATES A
GENERAL 3 TO 6 INCH ACCUMULATION FOR THE AREA...WITH ISOLATED
HEAVIER AMOUNTS NOT OUT OF THE QUESTION. THEREFORE...THE ENTIRE AREA
WILL REMAIN IN A WINTER WEATHER ADVISORY FROM TONIGHT THROUGH SUNDAY
AFTERNOON WITH THE STARTING TIMES SKEWED SLIGHTLY FROM WEST TO EAST.
WARM AIR ADVECTION AHEAD OF THE APPROACHING LOW WILL ALLOW
TEMPERATURES TO SLOWLY MODERATE FROM WEST TO EAST TONIGHT THROUGH
SUNDAY MORNING. SOME LOCATIONS MAY SEE READINGS APPROACHING THE
FREEZING MARK FOR HIGHS ON SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE CLIPPER SYSTEM RESPONSIBLE FOR
TONIGHT AND SUNDAY`S WIDESPREAD SNOWFALL WILL SLOWLY DRIFT EAST AND
WEAKEN INTO AN INVERTED TROUGH...AS ITS ENERGY TRANSFERS TO A
SECONDARY LOW DEVELOPING AND LIFTING NORTHEAST ALONG THE MID
ATLANTIC AND NEW ENGLAND COASTS.
WHILE THE STEADIEST AND HEAVIEST PRECIP ASSOCIATED WITH THE DECAYING
CLIPPER WILL BE ALREADY BE OVER WITH BY THE START OF THE PERIOD...
OUR AIRMASS WILL STILL BE COLD ENOUGH ALOFT...AND THE SYSTEM WILL
STILL HAVE ENOUGH LEFTOVER ENERGY TO KEEP A DECENT CHANCE OF SOME
PRECIP INTACT ACROSS THE ENTIRE AREA THOUGH MONDAY NIGHT. POPS
THROUGH THIS TIME FRAME WILL THUS GENERALLY RANGE FROM MID TO HIGH
CHANCE TO THE LOW LIKELY RANGE...WITH THE HIGHEST VALUES RESERVED
FOR AREAS ALONG AND EAST OF THE SURFACE OCCLUSION SUNDAY NIGHT...AND
THE ENTIRE AREA MONDAY MORNING AS THE SUPPORTING MID-LEVEL
LOW/DEFORMATION ZONE SLIDES EAST ACROSS NEW YORK STATE.
QPF FROM THE SHORT TERM GUIDANCE AND HPC IS GENERALLY LIGHT THROUGH
THE PERIOD...INDICATING THE POTENTIAL FOR 1-2 INCHES OF NUISANCE
SNOWFALL ACCUMULATIONS ACROSS THE BULK OF THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
IN GENERAL...HAVE OPTED TO FOLLOW THE MORE CONSISTENT ECMWF AND HPC
GUIDANCE WHEN PREPARING THE EXTENDED FORECAST...RATHER THAN THE GFS
WHICH HAS RECENTLY SHOWN A LOT OF RUN-TO-RUN INCONSISTENCY IN THE
TIMING AND STRENGTH OF THE LOW PROGGED TO AFFECT THE AREA LATE IN
THE WEEK. ALSO...GIVEN THE -20C OR COLDER 850 MB TEMPS PROJECTED BY
BOTH MODELS FOR NEXT WEEKEND...HAVE OPTED TO UNDERCUT MEX/HPC
GUIDANCE TEMPS FOR FRIDAY NIGHT AND SATURDAY...AS THESE APPEAR TO BE
TOO WARM.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE CENTERED OVER LAKE MICHIGAN THIS EVENING WILL MOVE
SLOWLY TO THE EAST TONIGHT AND SUNDAY...STAYING NORTHWEST OF LAKE
ONTARIO THROUGH THE TAF PERIOD. WARM AIR ADVECTION AHEAD OF THIS
SYSTEM AND ADDITIONAL LIFT AHEAD OF AN APPROACHING SHORT WAVE
WILL GENERATE PERIODS OF SNOW TONIGHT THROUGH SUNDAY MORNING.
A FIRST BATCH OF MAINLY LIGHT SNOW THAT IS IMPACTING WESTERN AND
CENTRAL NEW YORK THIS EVENING WILL SLIDE TO THE EAST AS AN
UPPER LEVEL JET STREAK MOVES OFF THE SOUTHERN NEW ENGLAND COAST.
A BETTER ORGANIZED AREA OF SNOW IS DEVELOPING OVER MICHIGAN...DUE TO
STRONGER LOW LEVEL MOISTURE CONVERGENCE IN THE VCNTY OF THE LOW
AND ADDED LIFT GENERATED BY THE WELL DEFINED SHORT WAVE THAT IS
DIVING SOUTHEAST TOWARD MICHIGAN. EXPECT THE STEADIER AREA OF SNOW
TO IMPACT OUR TAF SITES LATER TONIGHT THROUGH SUNDAY MORNING.
THROUGH THIS EVENING...EXPECT MAINLY VFR CIGS WITH VSBYS
OCCASIONALLY LOWERING TO MVFR OR IFR WITH THE LIGHT SNOW THAT IS
PASSING THROUGH THE AREA. UPSTREAM OBSERVATIONS CLOSER TO THE MAIN
CENTER OF THE LAKE MICHIGAN LOW SHOW CIGS VARYING BETWEEN MVFR AND
VFR...WHILE VSBYS ARE MAINLY AT IFR LEVELS. THESE TRENDS WILL MAKE
THE TIMING OF THE LOWER CONDITIONS VERY DIFFICULT TO FORECAST.
EXPECT THE STEADIER SNOW TO TAPER OFF FROM WEST TO EAST SUNDAY
AFTERNOON AS THE OCCLUDED FRONT...TRAILING SOUTH OF THE
AFOREMENTIONED LOW...MOVES EAST ACROSS THE STATE. A BURST OF SNOW IS
POSSIBLE WITH THE FRONTAL PASSAGE. STILL EXPECT MVFR CIGS TO THE
RULE ON SUNDAY...WITH VSBYS VARYING BETWEEN MVFR AND IFR.
SUNDAY NIGHT AND MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
MODEST SOUTHERLY WINDS WILL FRESHEN A BIT AND TURN MORE
SOUTHEASTERLY TONIGHT...THOUGH THE OFFSHORE FLOW WILL DIRECT THE
HIGHER WAVES AWAY FROM THE SOUTHERN AND EASTERN SHORES OF LAKE
ONTARIO...SO NO SMALL CRAFT ADVISORIES WILL BE NECESSARY.
ON SUNDAY AND SUNDAY NIGHT...WINDS WILL WEAKEN AND TURN MORE
WESTERLY TO SOUTHWESTERLY AS A WEAKENING AREA OF LOW PRESSURE OVER
SLOWLY DRIFTS EASTWARD ACROSS SOUTHERN ONTARIO. A RELATIVELY WEAK TO
MODERATE PRESSURE GRADIENT WILL THEN PERSIST THROUGH MONDAY AND
TUESDAY...AND THIS WILL RESULT IN WINDS AND WAVES REMAINING BELOW
SMALL CRAFT CRITERIA INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ001>008-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TJP/TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...JJR/LEVAN/TJP
MARINE...JJR
000
FXUS61 KBUF 180024
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
724 PM EST SAT JAN 17 2009
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL DRIFT EAST INTO
SOUTHERN ONTARIO TONIGHT AND SUNDAY...AND WILL BRING BOTH A GENERAL
SNOWFALL AND A RETURN TO MORE NORMAL MIDWINTER TEMPERATURES. THE LOW
WILL THEN SLOWLY WEAKEN IN PLACE OVER THE AREA SUNDAY NIGHT THROUGH
TUESDAY...WHILE KEEPING A GENERAL CHANCE OF SNOW SHOWERS ACROSS THE
REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE NEAR TERM PERIOD WILL FEATURE A RATHER COMPLEX WINTER WEATHER
SYSTEM WHICH WILL IMPACT WESTERN AND CENTRAL NEW YORK TONIGHT AND
SUNDAY. WATER VAPOR IMAGERY THIS AFTERNOON SHOWING A MID LEVEL SHORT
WAVE DROPPING SOUTHEAST ACROSS WISCONSIN AND UPPER MICHIGAN. THE
ASSOCIATED SURFACE LOW ANALYZED OVER CENTRAL WISCONSIN WITH ITS WARM
FRONT EXTENDING SOUTHWARD INTO THE WESTERN OHIO VALLEY. ASSOCIATED
WARM AIR ADVECTION PATTERN GENERATING A SWATH OF SNOW ALONG AND OUT
AHEAD OF IT...REACHING AS FAR EAST AS SOUTHERN ONTARIO AND NORTHWEST
PENNSYLVANIA. LEADING EDGE OF THIS SNOW AREA WILL SPREAD ACROSS
WESTERN SECTIONS LATE THIS AFTERNOON AND CONTINUING SPREADING
EASTWARD THROUGH EARLY TONIGHT.
WARM AIR ADVECTION PATTERN WILL INCREASE ACROSS THE AREA TONIGHT AS
THE SURFACE LOW TRACKS TO EASTERN MICHIGAN BY SUNDAY MORNING...FOCUS
STRENGTHENING LOW LEVEL JET ON WESTERN AND CENTRAL NEW YORK. MODEST
ISENTROPIC ASCENT DEVELOPS INTO THE AREA ALONG WITH DECENT 700 MB
FRONTOGENETIC FORCING AND PRESENCE OF 700 MB OMEGA MAXIMUM. ALL OF
THESE PARAMETERS LOOK TO WORK ACROSS THE AREA TONIGHT AND EARLY
SUNDAY...GENERALLY IN THE 03Z TO 15Z TIME FRAME. THESE PARAMETERS
ALSO LOOK TO IMPACT THE AREA IN A FAVORED THERMAL REGIME ALOFT WITH
MODEL SOUNDINGS SUGGESTING A NEARLY ISOTHERMAL PROFILE AT -15C ...
PRIME DENDRITIC GROWTH REGION FROM ABOUT 3K TO 10K FEET. WE WILL
LIKELY SEE A PERIOD OF MODERATE TO HEAVY SNOW ACROSS THE AREA DURING
A PORTION OF THIS TIME PERIOD. THERMAL PROFILES WOULD SUGGEST A
SNOW-WATER RATIO OF AROUND 20:1 TONIGHT...BEFORE DROPPING BACK TO
SOMETHING CLOSER TO 15:1 FOR SUNDAY AS TEMPERATURES WARM. SOME MODEL
BLEND COMBINED WITH HPC QPF LOOK TO HANDLE EXPECTED PRECIPITATION
SUFFICIENTLY AND GENERATES A GENERAL 3 TO 6 INCH ACCUMULATION FOR
THE AREA...WITH ISOLATED HEAVIER AMOUNTS NOT OUT OF THE QUESTION.
THEREFORE...HAVE PLACED THE ENTIRE AREA IN A WINTER WEATHER ADVISORY
BASICALLY FROM TONIGHT THROUGH SUNDAY AFTERNOON WITH THE STARTING
TIMES SKEWED SLIGHTLY FROM WEST TO EAST.
TEMPERATURES SHOULD BE NONDIURNAL TONIGHT IN THE WARM AIR ADVECTION
REGIME AS THEY SHOULD CONTINUE TO RISE SLOWLY WITH A SOUTH TO
SOUTHEAST FLOW ON THE EAST SIDE OF THE LOW TRACK. COULD SEE A FEW
LOCATIONS APPROACHING THE FREEZING MARK FOR HIGHS ON SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE CLIPPER SYSTEM RESPONSIBLE FOR
TONIGHT AND SUNDAY`S WIDESPREAD SNOWFALL WILL SLOWLY DRIFT EAST AND
WEAKEN INTO AN INVERTED TROUGH...AS ITS ENERGY TRANSFERS TO A
SECONDARY LOW DEVELOPING AND LIFTING NORTHEAST ALONG THE MID
ATLANTIC AND NEW ENGLAND COASTS.
WHILE THE STEADIEST AND HEAVIEST PRECIP ASSOCIATED WITH THE DECAYING
CLIPPER WILL BE ALREADY BE OVER WITH BY THE START OF THE PERIOD...
OUR AIRMASS WILL STILL BE COLD ENOUGH ALOFT...AND THE SYSTEM WILL
STILL HAVE ENOUGH LEFTOVER ENERGY TO KEEP A DECENT CHANCE OF SOME
PRECIP INTACT ACROSS THE ENTIRE AREA THOUGH MONDAY NIGHT. POPS
THROUGH THIS TIME FRAME WILL THUS GENERALLY RANGE FROM MID TO HIGH
CHANCE TO THE LOW LIKELY RANGE...WITH THE HIGHEST VALUES RESERVED
FOR AREAS ALONG AND EAST OF THE SURFACE OCCLUSION SUNDAY NIGHT...AND
THE ENTIRE AREA MONDAY MORNING AS THE SUPPORTING MID-LEVEL
LOW/DEFORMATION ZONE SLIDES EAST ACROSS NEW YORK STATE.
QPF FROM THE SHORT TERM GUIDANCE AND HPC IS GENERALLY LIGHT THROUGH
THE PERIOD...INDICATING THE POTENTIAL FOR 1-2 INCHES OF NUISANCE
SNOWFALL ACCUMULATIONS ACROSS THE BULK OF THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
IN GENERAL...HAVE OPTED TO FOLLOW THE MORE CONSISTENT ECMWF AND HPC
GUIDANCE WHEN PREPARING THE EXTENDED FORECAST...RATHER THAN THE GFS
WHICH HAS RECENTLY SHOWN A LOT OF RUN-TO-RUN INCONSISTENCY IN THE
TIMING AND STRENGTH OF THE LOW PROGGED TO AFFECT THE AREA LATE IN
THE WEEK. ALSO...GIVEN THE -20C OR COLDER 850 MB TEMPS PROJECTED BY
BOTH MODELS FOR NEXT WEEKEND...HAVE OPTED TO UNDERCUT MEX/HPC
GUIDANCE TEMPS FOR FRIDAY NIGHT AND SATURDAY...AS THESE APPEAR TO BE
TOO WARM.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
LOW PRESSURE CENTERED OVER LAKE MICHIGAN THIS EVENING WILL MOVE
SLOWLY TO THE EAST TONIGHT AND SUNDAY...STAYING NORTHWEST OF LAKE
ONTARIO THROUGH THE TAF PERIOD. WARM AIR ADVECTION AHEAD OF THIS
SYSTEM AND ADDITIONAL LIFT AHEAD OF AN APPROACHING SHORT WAVE
WILL GENERATE PERIODS OF SNOW TONIGHT THROUGH SUNDAY MORNING.
A FIRST BATCH OF MAINLY LIGHT SNOW THAT IS IMPACTING WESTERN AND
CENTRAL NEW YORK THIS EVENING WILL SLIDE TO THE EAST AS AN
UPPER LEVEL JET STREAK MOVES OFF THE SOUTHERN NEW ENGLAND COAST.
A BETTER ORGANIZED AREA OF SNOW IS DEVELOPING OVER MICHIGAN...DUE TO
STRONGER LOW LEVEL MOISTURE CONVERGENCE IN THE VCNTY OF THE LOW
AND ADDED LIFT GENERATED BY THE WELL DEFINED SHORT WAVE THAT IS
DIVING SOUTHEAST TOWARD MICHIGAN. EXPECT THE STEADIER AREA OF SNOW
TO IMPACT OUR TAF SITES LATER TONIGHT THROUGH SUNDAY MORNING.
THROUGH THIS EVENING...EXPECT MAINLY VFR CIGS WITH VSBYS
OCCASIONALLY LOWERING TO MVFR OR IFR WITH THE LIGHT SNOW THAT IS
PASSING THROUGH THE AREA. UPSTREAM OBSERVATIONS CLOSER TO THE MAIN
CENTER OF THE LAKE MICHIGAN LOW SHOW CIGS VARYING BETWEEN MVFR AND
VFR...WHILE VSBYS ARE MAINLY AT IFR LEVELS. THESE TRENDS WILL MAKE
THE TIMING OF THE LOWER CONDITIONS VERY DIFFICULT TO FORECAST.
EXPECT THE STEADIER SNOW TO TAPER OFF FROM WEST TO EAST SUNDAY
AFTERNOON AS THE OCCLUDED FRONT...TRAILING SOUTH OF THE
AFOREMENTIONED LOW...MOVES EAST ACROSS THE STATE. A BURST OF SNOW IS
POSSIBLE WITH THE FRONTAL PASSAGE. STILL EXPECT MVFR CIGS TO THE
RULE ON SUNDAY...WITH VSBYS VARYING BETWEEN MVFR AND IFR.
SUNDAY NIGHT AND MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
MODEST SOUTHERLY WINDS WILL FRESHEN A BIT AND TURN MORE
SOUTHEASTERLY TONIGHT...THOUGH THE OFFSHORE FLOW WILL DIRECT THE
HIGHER WAVES AWAY FROM THE SOUTHERN AND EASTERN SHORES OF LAKE
ONTARIO...SO NO SMALL CRAFT ADVISORIES WILL BE NECESSARY.
ON SUNDAY AND SUNDAY NIGHT...WINDS WILL WEAKEN AND TURN MORE
WESTERLY TO SOUTHWESTERLY AS A WEAKENING AREA OF LOW PRESSURE OVER
SLOWLY DRIFTS EASTWARD ACROSS SOUTHERN ONTARIO. A RELATIVELY WEAK TO
MODERATE PRESSURE GRADIENT WILL THEN PERSIST THROUGH MONDAY AND
TUESDAY...AND THIS WILL RESULT IN WINDS AND WAVES REMAINING BELOW
SMALL CRAFT CRITERIA INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ006>008.
WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ001>005-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...JJR/LEVAN/TJP
MARINE...JJR
000
FXUS61 KBUF 172001
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
301 PM EST SAT JAN 17 2009
.SYNOPSIS...
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL DRIFT EAST INTO
SOUTHERN ONTARIO TONIGHT AND SUNDAY...AND WILL BRING BOTH A GENERAL
SNOWFALL AND A RETURN TO MORE NORMAL MIDWINTER TEMPERATURES. THE LOW
WILL THEN SLOWLY WEAKEN IN PLACE OVER THE AREA SUNDAY NIGHT THROUGH
TUESDAY...WHILE KEEPING A GENERAL CHANCE OF SNOW SHOWERS ACROSS THE
REGION.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE NEAR TERM PERIOD WILL FEATURE A RATHER COMPLEX WINTER WEATHER
SYSTEM WHICH WILL IMPACT WESTERN AND CENTRAL NEW YORK TONIGHT AND
SUNDAY. WATER VAPOR IMAGERY THIS AFTERNOON SHOWING A MID LEVEL SHORT
WAVE DROPPING SOUTHEAST ACROSS WISCONSIN AND UPPER MICHIGAN. THE
ASSOCIATED SURFACE LOW ANALYZED OVER CENTRAL WISCONSIN WITH ITS WARM
FRONT EXTENDING SOUTHWARD INTO THE WESTERN OHIO VALLEY. ASSOCIATED
WARM AIR ADVECTION PATTERN GENERATING A SWATH OF SNOW ALONG AND OUT
AHEAD OF IT...REACHING AS FAR EAST AS SOUTHERN ONTARIO AND NORTHWEST
PENNSYLVANIA. LEADING EDGE OF THIS SNOW AREA WILL SPREAD ACROSS
WESTERN SECTIONS LATE THIS AFTERNOON AND CONTINUING SPREADING
EASTWARD THROUGH EARLY TONIGHT.
WARM AIR ADVECTION PATTERN WILL INCREASE ACROSS THE AREA TONIGHT AS
THE SURFACE LOW TRACKS TO EASTERN MICHIGAN BY SUNDAY MORNING...FOCUS
STRENGTHENING LOW LEVEL JET ON WESTERN AND CENTRAL NEW YORK. MODEST
ISENTROPIC ASCENT DEVELOPS INTO THE AREA ALONG WITH DECENT 700 MB
FRONTOGENETIC FORCING AND PRESENCE OF 700 MB OMEGA MAXIMUM. ALL OF
THESE PARAMETERS LOOK TO WORK ACROSS THE AREA TONIGHT AND EARLY
SUNDAY...GENERALLY IN THE 03Z TO 15Z TIME FRAME. THESE PARAMETERS
ALSO LOOK TO IMPACT THE AREA IN A FAVORED THERMAL REGIME ALOFT WITH
MODEL SOUNDINGS SUGGESTING A NEARLY ISOTHERMAL PROFILE AT -15C ...
PRIME DENDRITIC GROWTH REGION FROM ABOUT 3K TO 10K FEET. WE WILL
LIKELY SEE A PERIOD OF MODERATE TO HEAVY SNOW ACROSS THE AREA DURING
A PORTION OF THIS TIME PERIOD. THERMAL PROFILES WOULD SUGGEST A
SNOW-WATER RATIO OF AROUND 20:1 TONIGHT...BEFORE DROPPING BACK TO
SOMETHING CLOSER TO 15:1 FOR SUNDAY AS TEMPERATURES WARM. SOME MODEL
BLEND COMBINED WITH HPC QPF LOOK TO HANDLE EXPECTED PRECIPITATION
SUFFICIENTLY AND GENERATES A GENERAL 3 TO 6 INCH ACCUMULATION FOR
THE AREA...WITH ISOLATED HEAVIER AMOUNTS NOT OUT OF THE QUESTION.
THEREFORE...HAVE PLACED THE ENTIRE AREA IN A WINTER WEATHER ADVISORY
BASICALLY FROM TONIGHT THROUGH SUNDAY AFTERNOON WITH THE STARTING
TIMES SKEWED SLIGHTLY FROM WEST TO EAST.
TEMPERATURES SHOULD BE NONDIURNAL TONIGHT IN THE WARM AIR ADVECTION
REGIME AS THEY SHOULD CONTINUE TO RISE SLOWLY WITH A SOUTH TO
SOUTHEAST FLOW ON THE EAST SIDE OF THE LOW TRACK. COULD SEE A FEW
LOCATIONS APPROACHING THE FREEZING MARK FOR HIGHS ON SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
IN THE SHORT TERM PERIOD...THE CLIPPER SYSTEM RESPONSIBLE FOR
TONIGHT AND SUNDAY`S WIDESPREAD SNOWFALL WILL SLOWLY DRIFT EAST AND
WEAKEN INTO AN INVERTED TROUGH...AS ITS ENERGY TRANSFERS TO A
SECONDARY LOW DEVELOPING AND LIFTING NORTHEAST ALONG THE MID
ATLANTIC AND NEW ENGLAND COASTS.
WHILE THE STEADIEST AND HEAVIEST PRECIP ASSOCIATED WITH THE DECAYING
CLIPPER WILL BE ALREADY BE OVER WITH BY THE START OF THE PERIOD...
OUR AIRMASS WILL STILL BE COLD ENOUGH ALOFT...AND THE SYSTEM WILL
STILL HAVE ENOUGH LEFTOVER ENERGY TO KEEP A DECENT CHANCE OF SOME
PRECIP INTACT ACROSS THE ENTIRE AREA THOUGH MONDAY NIGHT. POPS
THROUGH THIS TIME FRAME WILL THUS GENERALLY RANGE FROM MID TO HIGH
CHANCE TO THE LOW LIKELY RANGE...WITH THE HIGHEST VALUES RESERVED
FOR AREAS ALONG AND EAST OF THE SURFACE OCCLUSION SUNDAY NIGHT...AND
THE ENTIRE AREA MONDAY MORNING AS THE SUPPORTING MID-LEVEL
LOW/DEFORMATION ZONE SLIDES EAST ACROSS NEW YORK STATE.
QPF FROM THE SHORT TERM GUIDANCE AND HPC IS GENERALLY LIGHT THROUGH
THE PERIOD...INDICATING THE POTENTIAL FOR 1-2 INCHES OF NUISANCE
SNOWFALL ACCUMULATIONS ACROSS THE BULK OF THE AREA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
IN GENERAL...THE STRONG +PNA PATTERN OVER NORTH AMERICA WILL HAVE A
TENDENCY TO GRADUALLY RELAX IN THE LONG TERM PORTION OF THE FORECAST
AND BEYOND...WITH THE LARGE SCALE FLOW BECOMING NOTICEABLY LESS
AMPLIFIED WITH TIME. THIS WILL RESULT IN A RETURN TO MORE SEASONABLE
TEMPERATURES FOR THE MIDDLE AND LATTER PORTIONS OF THE WEEK ACROSS
OUR AREA...FOLLOWED BY A SHORT-LIVED SHOT OF RATHER COLD AIR FOR
NEXT WEEKEND AS UPPER TROUGHING OVER THE EASTERN THIRD OF THE
CONTINENT BRIEFLY GETS REINFORCED. THEREAFTER...IT APPEARS A
LONGER-LIVED PERIOD OF MORE NORMAL TEMPERATURES MAY FINALLY ARRIVE
FOR THE FINAL THE WEEK OF THE MONTH AS THE FLOW ALOFT BECOMES MUCH
MORE ZONAL.
LOOKING A LITTLE MORE CLOSELY AT THE FORECAST DETAILS FOR NEXT
WEEK...LINGERING UPPER TROUGHING AND AN ASSOCIATED NORTHWEST FLOW OF
COLD AIR ALOFT WILL RESULT IN A LOW CHANCE OF SNOW SHOWERS SOUTH AND
SOUTHEAST OF THE LOWER LAKES TUESDAY MORNING...THOUGH THIS WILL HAVE
A TENDENCY TO FADE AS THE DAY PROGRESSES AND LOW-LEVEL RIDGING
BUILDS EAST FROM THE CENTRAL GREAT LAKES. THE AFOREMENTIONED
LOW-LEVEL RIDGE WILL THEN CREST ACROSS THE AREA TUESDAY NIGHT...
RESULTING IN A RARE BUT ALSO BRIEF PERIOD OF DRY WEATHER.
ON WEDNESDAY...LOW PRESSURE TRACKING ACROSS NORTHERN ONTARIO SHOULD
DRAG ITS ASSOCIATED WEAK TO MODEST COLD FRONT SOUTHEAST INTO THE
AREA DURING THE DAY...RESULTING IN A GENERAL CHANCE FOR SOME SNOW
SHOWERS...WHICH COULD BE ENHANCED A LITTLE SOUTHEAST OF LAKE
ONTARIO. THE LATEST GFS/ECMWF ARE IN GENERAL AGREEMENT THAT THIS
FRONT SHOULD THEN STALL OUT NEAR OR OVER OUR AREA WEDNESDAY NIGHT
INTO FRIDAY AS A WAVE OF LOW PRESSURE DEVELOPS AND TRACKS EAST ALONG
THE BOUNDARY...THUS HAVE CONTINUED WITH CHANCE POPS DURING THIS
PERIOD...WITH THE BEST CHANCES RESERVED FOR FRIDAY AS THE LOW TRACKS
EAST ACROSS THE AREA. FOLLOWING THE PASSAGE OF THIS LOW...A SHOT OF
MUCH COLDER AIR SHOULD THEN RETURN FOR FRIDAY NIGHT AND SATURDAY.
IN GENERAL...HAVE OPTED TO FOLLOW THE MORE CONSISTENT ECMWF AND HPC
GUIDANCE WHEN PREPARING THE EXTENDED FORECAST...RATHER THAN THE GFS
WHICH HAS RECENTLY SHOWN A LOT OF RUN-TO-RUN INCONSISTENCY IN THE
TIMING AND STRENGTH OF THE LOW PROGGED TO AFFECT THE AREA LATE IN
THE WEEK. ALSO...GIVEN THE -20C OR COLDER 850 MB TEMPS PROJECTED BY
BOTH MODELS FOR NEXT WEEKEND...HAVE OPTED TO UNDERCUT MEX/HPC
GUIDANCE TEMPS FOR FRIDAY NIGHT AND SATURDAY...AS THESE APPEAR TO BE
TOO WARM.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
LAKE EFFECT SNOW SHOWERS ARE DIMINISHING ACROSS LAKE ONTARIO EARLY
THIS AFTERNOON AS SHEAR INCREASES. FLIGHT REGULATIONS WILL IMPROVE
TO VFR LATER THIS AFTERNOON FOR THE KART TERMINAL. ELSEWHERE MID
LEVEL CLOUDS AND VFR FLIGHT CONDITIONS WILL DETERIORATE TO IFR
FLIGHT CONDITIONS AS A CLIPPER SYSTEM MOVES ACROSS THE AREA.
BASED ON UPSTREAM OBS FROM ACROSS MICHIGAN...VISIBILITIES WILL
REDUCE TO IFR AND LATER LIFR JUST AFTER THE ONSET OF SNOW. CIGS WILL
ALSO QUICKLY DROP INTO THE LOW MVFR RANGE AND REMAIN THERE
OVERNIGHT. CIGS WILL ALSO LOWER INTO IFR ACROSS THE SOUTHERN TIER.
THE HEAVIEST SNOW WILL END FROM WEST TO EAST ACROSS THE REGION.
LIGHT SNOW SHOWERS WILL STILL REMAIN IN THE REGION SUNDAY MORNING AS
THE UPPER LEVEL TROUGH REMAINS TO THE WEST OF THE REGION.
SUNDAY NIGHT AND MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
MODEST SOUTHERLY WINDS WILL FRESHEN A BIT AND TURN MORE
SOUTHEASTERLY TONIGHT...THOUGH THE OFFSHORE FLOW WILL DIRECT THE
HIGHER WAVES AWAY FROM THE SOUTHERN AND EASTERN SHORES OF LAKE
ONTARIO...SO NO SMALL CRAFT ADVISORIES WILL BE NECESSARY.
ON SUNDAY AND SUNDAY NIGHT...WINDS WILL WEAKEN AND TURN MORE
WESTERLY TO SOUTHWESTERLY AS A WEAKENING AREA OF LOW PRESSURE OVER
SLOWLY DRIFTS EASTWARD ACROSS SOUTHERN ONTARIO. A RELATIVELY WEAK TO
MODERATE PRESSURE GRADIENT WILL THEN PERSIST THROUGH MONDAY AND
TUESDAY...AND THIS WILL RESULT IN WINDS AND WAVES REMAINING BELOW
SMALL CRAFT CRITERIA INTO MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 4 PM EST
SUNDAY FOR NYZ006>008.
WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ003>005-
013-014.
WINTER WEATHER ADVISORY UNTIL 4 PM EST SUNDAY FOR NYZ001-002-
010>012-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...JJR
NEAR TERM...TMA
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...JJR/THOMAS
MARINE...JJR
000
FXUS61 KBUF 171738
AFDBUF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BUFFALO NY
1238 PM EST SAT JAN 17 2009
.SYNOPSIS...
LAKE EFFECT SNOW WILL LIFT TO THE NORTH AND DISSIPATE TODAY THEN LOW
PRESSURE MOVING TO THE CENTRAL GREAT LAKES WILL BRING A GENERAL
SNOWFALL TO THE AREA. THE EFFECTS OF THIS LOW WILL LINGER THROUGH
MONDAY NIGHT. TEMPERATURES WILL MODERATE THIS WEEKEND WITH HIGHS IN
THE UPPER TEENS TO NEAR 20 TODAY AND TO THE UPPER 20S ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONGOING LAKE SNOWS OFF OF LAKE ONTARIO HAVE BEEN CENTERED MAINLY
AROUND THE WATERTOWN AREA THIS MORNING. A NORTHWARD DRIFTING ALONG
WITH A NOTICEABLE WEAKENING TREND HAS BEEN TAKING PLACE OVER THE
LAST COUPLE HOURS. SHEAR HAS BEEN INCREASING ACROSS THIS AREA AHEAD
OF APPROACHING CLIPPER SYSTEM AND WARM FRONTAL BOUNDARY. SOME DRIER
AIR HAS ALSO BEEN ENTRAINING INTO THE AREA AS RIDGE CROSSES. WE
EXPECT THIS WEAKENING TREND TO CONTINUE THIS AFTERNOON AND MAY BE
ABLE TO CANCEL WARNING EARLIER THAN EXPECTED. WILL CONTINUE TO
MONITOR RADAR TRENDS. WIND CHILL VALUES ACROSS THE AREA HAVE RISEN
ABOVE ADVISORY CRITERIA LATE MORNING AND THE WIND CHILL ADVISORY HAS
BEEN ALLOW TO EXPIRE ON SCHEDULE. TEMPERATURES AND WIND CHILL VALUES
WILL CONTINUE TO RISE THE REMAINDER OF THE AFTERNOON AS WARM AIR
ADVECTION PATTERN CONTINUES TO STRENGTHEN ACROSS THE AREA.
OUR ATTENTION THEN TURNS TO A CLIPPER DROPPING SOUTHEAST FROM
MINNESOTA. THIS WILL PRODUCE A WIDESPREAD SNOWFALL ACROSS OUR ENTIRE
CWA. START TIMES LOOK TO BE NEAR SUNSET TODAY FOR THE WEST THEN
SPREADING QUICKLY EAST OVERNIGHT. AT THIS TIME WE WILL NOT POST ANY
HEADLINES. FOR THE MOST PART 2 TO 4 INCHES SHOULD WORK BUT LATER
SHIFTS WILL HAVE TO MONITOR FOR POTENTIAL ADVISORY CRITERIA. WE WILL
BE AT THE NOSE OF A 40 KNOT 850 JET BETWEEN 00Z AND 06Z. UPPER JET
DYNAMICS ARE NOT FAVORABLE AS WE WILL BE IN THE LEFT REAR QUADRANT
OF THE 250 MB JET.
TEMPERATURES WILL BE NONDIURNAL OVERNIGHT AS THEY CONTINUE TO RISE
SLOWLY WITH THE SOUTH TO SOUTHEAST FLOW ON THE EAST SIDE OF THE
CLIPPER.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY/...
THE CLIPPER RESPONSIBLE FOR THE WIDESPREAD SNOWFALL WILL SETTLE INTO
THE EASTERN LAKE BASIN AND SLOWLY FILL AS A COASTAL LOW DEVELOPS
SUNDAY NIGHT. THE CLOSED UPPER LOW WILL BE TO OUR WEST DURING SUNDAY
AND SLIDE TO THE EAST OF THE REGION BY MONDAY MORNING...THUS THE
POPS WILL REMAIN IN THE LOW CATEGORICAL TO LIKELY RANGE SUNDAY AND
SUNDAY NIGHT. QPF DURING SUNDAY AND SUNDAY NIGHT STILL SUPPORTS
ADDITIONAL SNOWFALL OF A COUPLE INCHES...MAINLY ALONG THE MID LEVEL
DEFORMATION ZONE OVER WESTERN NY TO THE WESTERN FINGER LAKES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE FILLING SURFACE LOW WHICH WAS THE WEEKEND CLIPPER WILL REMAIN
AS A TROUGH ACROSS THE LAKES THROUGH TUESDAY MORNING. A RETURN OF
NORTH TO NORTHWEST WINDS WILL BRING SCATTERED LAKE SNOW TO THE
SOUTH AND SOUTHEAST OF LAKE ONTARIO MONDAY NIGHT THROUGH TUESDAY
EVENING AS -14C TO -16C 850MB AIR SETTLES IN ACROSS THE REGION
ONCE AGAIN. RIDGING ACROSS THE EASTERN LAKES WILL OFFER A BREAK IN
THE SNOW AND CLOUDS ON WEDNESDAY...AND THE OPPORTUNITY FOR PARTIAL
CLEARING TUESDAY NIGHT AND EARLY WEDNESDAY. GFS AND ECMWF SET UP A
SHARP THERMAL BOUNDARY ACROSS THE LAKES AND NORTHEASTERN STATES ON
THURSDAY AND FRIDAY WITH A ZONAL FLOW ALOFT. THIS WILL BRING A
CHANCE OF SNOW BACK ON THURSDAY AND A BETTER CHANCE ON FRIDAY AS A
LOW FORMS ALONG THE FRONTAL BOUNDARY. TEMPERATURES WILL BE LESS
CERTAIN AS THE STATIONARY FRONT MAY BE JUST TO OUR NORTH AND
PROVIDE NEAR NORMAL TEMPS...OR JUST TO OUR SOUTH AND KEEP US WITH
BELOW NORMAL TEMPS. WILL GO NEAR THE MEX GUIDANCE AND HAVE END OF
WEEK HIGH TEMPS IN THE LOW 30S AND LOWS IN THE MID TEENS...CLOSE
TO SEASONAL NORMALS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
LAKE EFFECT SNOW SHOWERS ARE DIMINISHING ACROSS LAKE ONTARIO EARLY
THIS AFTERNOON AS SHEAR INCREASES. FLIGHT REGULATIONS WILL IMPROVE
TO VFR LATER THIS AFTERNOON FOR THE KART TERMINAL. ELSEWHERE MID
LEVEL CLOUDS AND VFR FLIGHT CONDITIONS WILL DETERIORATE TO IFR
FLIGHT CONDITIONS AS A CLIPPER SYSTEM MOVES ACROSS THE AREA.
BASED ON UPSTREAM OBS FROM ACROSS MICHIGAN...VISIBILITIES WILL
REDUCE TO IFR AND LATER LIFR JUST AFTER THE ONSET OF SNOW. CIGS WILL
ALSO QUICKLY DROP INTO THE LOW MVFR RANGE AND REMAIN THERE
OVERNIGHT. CIGS WILL ALSO LOWER INTO IFR ACROSS THE SOUTHERN TIER.
THE HEAVIEST SNOW WILL END FROM WEST TO EAST ACROSS THE REGION.
LIGHT SNOW SHOWERS WILL STILL REMAIN IN THE REGION SUNDAY MORNING AS
THE UPPER LEVEL TROUGH REMAINS TO THE WEST OF THE REGION.
SUNDAY NIGHT AND MONDAY...MVFR IN SNOW SHOWERS.
TUESDAY...VFR/MVFR IN SCT SNOW SHOWERS.
WEDNESDAY...MVFR IN CHC SNOW SHWRS...WITH POSSIBLE LAKE EFFECT SE OF
LAKE ONTARIO.
THURSDAY...MVFR IN CHC SNOW SHOWERS...IFR IN POSSIBLE LAKE SNOWS
EAST OF LAKE ONTARIO.
&&
.MARINE...
WESTERLY WINDS WILL BACK TO THE SOUTH TODAY AND TO THE SOUTHEAST
TONIGHT. THIS WILL DIRECT THE WAVES AWAY FROM THE SOUTHERN AND
EASTERN SHORE OF LAKE ONTARIO WITH THE HIGHER WAVE TOWARD THE CENTER
AND NORTHERN SHORE OF THE LAKE. THE LACK OF SIGNIFICANT PRESSURE
GRADIENTS WILL KEEP WINDS IN THE 10 TO 15 KNOT RANGE WITH WAVES
GENERALLY 2 FEET OR LESS THROUGH MID WEEK.
THE NEARSHORE FORECASTS FOR LAKE ERIE AND THE NIAGARA RIVER HAVE
ENDED FOR THE SEASON AND WILL RESUME IN MARCH. NEARSHORE FORECASTS
FOR LAKE ONTARIO WILL CONTINUE.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW WARNING UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ007-008.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
LOZ042>045.
&&
$$
SYNOPSIS...WCH
NEAR TERM...SAGE/TMA
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...JJR/THOMAS
MARINE...WCH
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