000
FXUS63 KBIS 201028
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
415 AM CST TUE JAN 20 2009
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...
LATEST WATER VAPOR IMAGERY SHOWS THE UPPER HIGH OVER EASTERN IDAHO
WITH STRONG SUBSIDENCE ALOFT OCCURRING ALONG/EAST OF THE RIDGE AXIS
WHICH ENCOMPASSES WESTERN AND CENTRAL NORTH DAKOTA THIS MORNING.
AN UPPER AIR DISTURBANCE WAS SEEN ROTATING AROUND THE RIDGE AXIS
MOVING THROUGH CENTRAL/SOUTHEAST SASKATCHEWAN. WAVE HAS NOTHING TO
WORK WITH IN TERMS OF MOISTURE AND VORTICITY ADVECTION IS MAINLY
CHANNELED...THUS NO IMPACT TO THE OVERALL FORECAST. LATEST SURFACE
ANALYSIS SHOWS A WEAK TROF ASSOCIATED WITH UPPER
SHORTWAVE...STRETCHING FROM WESTERN MANITOBA TO SOUTH CENTRAL
SASKATCHEWAN. PRESSURE FALLS OF 1MB TO 3MB PER 3HR PERIOD WERE
OCCURRING OVER CENTRAL AND WESTERN NORTH DAKOTA. SKIES WERE CLEAR ON
EITHER SIDE OF THE TROUGH WITH MAINLY A WIND SHIFT TO THE WEST AND
NORTHWEST BEHIND IT. STRONG NVA/SUBSIDENCE BEHIND THE UPPER WAVE IS
EVIDENT ON THE NAM/GFS BUFR SOUNDINGS THIS AFTERNOON. THUS THE
CURRENT MID LEVEL SUBSIDENCE INVERSION WILL STRENGTHEN AND FURTHER
DESCEND TO NEAR THE SURFACE THIS AFTERNOON. SOUNDINGS SHOW THAT ANY
SURFACE MIXED LAYER IS EXTREMELY SHALLOW OR NON-EXISTENT. WITH THE
SUBSIDENCE INVERSION LOWERING TO NEAR THE SURFACE AND WITH THE
PASSAGE OF THE WEAK/SHALLOW SURFACE TROUGH MENTIONED ABOVE...EXPECT
SUSTAINED NORTHWEST WINDS OF 15 TO 20 MPH THIS AFTERNOON WITH GUSTS
TO 25 MPH. HIGHS TODAY WILL BE WARMER THAN YESTERDAY...BUT HAVE GONE
BELOW GUIDANCE IN A FEW AREAS WHERE CURRENT TEMPS ARE SEVERAL
DEGREES COLDER THAN WHAT GUIDANCE WAS FORECASTING FOR AT THIS VERY
SAME TIME.
THE LATEST FOG/STRATUS IMAGERY PLACES THE BACK EDGE OF LOW CLOUDS
AROUND JAMESTOWN AND SOUTH. THE RUC13 BOUNDARY LAYER RH KEEPS THIS
AREA IN TACT THROUGH THE MORNING HOURS WHILE THE NAM/GFS ERODE IT
BY/AROUND 12Z TODAY. WILL ADJUST SKY GRIDS AS NEEDED UP UNTIL
FORECAST TIME...BUT WILL PROBABLY BEGIN THE MORNING WITH MOSTLY
CLOUDY SKIES AT KJMS AND SOUTH WITH DECREASING CLOUDS/CLEARING TAKING
PLACE LATER THIS MORNING/AFTERNOON. THE UPPER RIDGE BEGINS TO FLATTEN
WEDNESDAY WITH LITTLE OR NO CHANGE TO OUR WEATHER...AS TEMPERATURES
WILL BE A COUPLE DEGREES COOLER THAN TODAY. WITH CLEAR SKIES TONIGHT
AND LIGHT WINDS...HAVE OPTED TO LOWER MIN TEMPS MORE IN LINE WITH
CURRENT GUIDANCE. ATTENTION TURNS TO ANOTHER ARCTIC BOUNDARY
DROPPING INTO SOUTHERN CANADA WEDNESDAY NIGHT...AND THROUGH NORTH
DAKOTA DURING THE DAY THURSDAY. CONSEQUENTLY TEMPERATURES LOOK TO
FALL DURING THE MORNING ACROSS THE NORTH...AND IN THE AFTERNOON
CENTRAL AND SOUTH. THIS IS ALL DEPENDENT ON THE TIMING OF THE
FRONT BUT GOOD AGREEMENT AMONG THE NAM/GFS FOR CURRENT TIMING.
COLD AIR ADVECTION WILL LEAD TO A SLIGHT CHANCE OF SNOW THURSDAY
THROUGH THURSDAY NIGHT BUT NOTHING TOO IMPRESSIVE AS LIQUID QPF
AMOUNTS ARE ONLY AROUND A HUNDREDTH OF AN INCH. THE MAIN HEADLINE
WILL COME WITH THE ONSET OF THE FRIGID TEMPS THURSDAY NIGHT.
.LONG TERM...FRIDAY THROUGH TUESDAY NIGHT
AN ARCTIC HIGH PRESSURE CENTER WILL KEEP TEMPERATURES BELOW NORMAL
DURING THE LONG TERM FORECAST PERIOD. UPSLOPE RETURN FLOW AND LEE
SIDE SURFACE LOW FORMATION OVER THE WESTERN HIGH PLAINS WILL BRING A
SMALL CHANCE OF LIGHT SNOW TO THE FAR SOUTHWEST...BUT AS YOU TRAVEL
NORTH AND EAST OF THERE...SKIES WILL QUICKLY CLEAR AND TEMPERATURES
WILL BE COLDER. THIS COLD DRY PATTERN WILL PERSIST INTO NEXT WEEK.
&&
.AVIATION...
SOME EARLY MORNING LOW STRATUS IN THE JAMESTOWN AREA WILL PULL EAST
EARLY THIS MORNING LEAVING THE ENTIRE FORECAST AREA WITH GOOD VFR
FLYING WEATHER TODAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
KS/RSL
000
FXUS63 KBIS 192103
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
305 PM CST MON JAN 19 2009
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...
MAIN FORECAST PROBLEM IN THE SHORT TERM WILL BE TEMPERATURES. MODELS
IN GOOD AGREEMENT AND UTILIZED A GFS/NAM BLEND FOR MOST FORECAST
ELEMENTS.
CURRENTLY...NORTHERN PLAINS REMAINS ON THE BOUNDARY OF THE
RIDGE-TROUGH UPPER AIR PATTERN ACROSS THE U.S. THIS IS STILL
PRODUCING SOME GUSTY WINDS OVER THE AREA BETWEEN THE SURFACE HIGH
OVER THE ROCKIES AND LOW PRESSURE FROM THE GREAT LAKES TO THE
MID-ATLANTIC REGION. ADVISORY WINDS HAVE BEEN MARGINAL AT BEST IN
THE SOUTHEAST TODAY AND WILL CANCEL THE WIND ADVISORY WITH THE
AFTERNOON ZONE ISSUANCE.
EXCEPT FOR SOME LOWER STRATUS HANGING ON IN THE FAR EAST THIS
EVENING...EXPECT CLEAR SKIES ACROSS THE LOCAL AREA TONIGHT. MINIMUM
TEMPERATURES WILL ONCE AGAIN BE TRICKY. THINK WE WILL SEE A LITTLE
LESS WIND THAN LAST NIGHT. GUIDANCE IS CERTAINLY HINTING AT THIS AND
WITH THE DEEP SNOWPACK AND CLEAR SKIES...WE COULD CERTAINLY DROP
PRETTY RAPIDLY. WILL NOT GO QUITE AS LOW AS GUIDANCE THOUGH AS WE
STILL HAVE A LITTLE WIND AND WARMEST MID LEVEL TEMPERATURES ARE
WORKING THEIR WAY INTO THE WEST OVERNIGHT.
SUNNY DAY ON TUESDAY. A WEAK TROUGH TRAVERSES THE AREA...WITH A
MODERATE WEST TO NORTHWEST WIND BEHIND IT. THIS SHOULD HELP US WARM
A COUPLE OF DEGREES WARMER THAN TODAY. THE FAR SOUTHWEST WILL
DEFINITELY BE THE WARMEST...BUT HAVE TRENDED BACK ON THEIR HIGH
TEMPERATURES. ALTHOUGH SNOW DEPTH HERE IS THE LEAST OF ANYWHERE IN
THE CWA...THERE IS STILL ENOUGH SNOW ON THE GROUND KEEP DAYTIME
HIGHS FROM GETTING TOO MILD.
WEDNESDAY WILL BE ANOTHER MILD DAY...PERHAPS A BIT WARMER IN THE
EAST AND NOT QUITE AS WARM IN THE WEST. ON THURSDAY...COLD AIR
SPILLS INTO THE REGION FROM THE NORTH. MODELS HAVE DELAYED THE ONSET
OF COLD AIR FROM YESTERDAYS MODEL RUNS...BRINGING THE BRUNT OF THE
COLD AIR ADVECTION THURSDAY NIGHT. WE HAVE THEREFORE RAISED
TEMPERATURES ON THURSDAY AND LIMITED ANY MENTION OF LIGHT SNOW TO
THE FAR NORTHERN TIER COUNTIES. WILL THEN BRING A SLIGHT CHANCE
SOUTHWARD THURSDAY NIGHT...ALONG WITH MUCH COLDER TEMPERATURES.
.LONG TERM...FRIDAY THROUGH MONDAY...
AN UPPER LEVEL POLAR VORTEX POSITIONED ACROSS NORTHEASTERN NORTH
AMERICA WILL KEEP THE MUCH COLDER ARCTIC AIR NORTHEAST OF THE LOCAL
AREA DURING THE EXTENDED PERIOD. STILL MUCH COLDER THAN WHAT WE ARE
CURRENTLY REALIZING AS DAYTIME AND NIGHTTIME TEMPERATURES THIS
COMING WEEKEND AND INTO THE EARLY PORTIONS OF NEXT WEEK WILL FALL TO
BELOW NORMAL FOR JANUARY. THE MAIN STORM TRACK ALSO LOOKS TO
STAY TO OUR SOUTH WITH ONLY SMALL CHANCES FOR LIGHT SNOW LATER THIS
COMING WEEKEND AND INTO MONDAY. WILL NEED TO KEEP AN EYE ON THIS
HOWEVER AS MY SOUTHWESTERN COUNTIES MAY POSSIBLY SEE ACCUMULATING
SNOWFALL SUNDAY NIGHT INTO MONDAY DEPENDING ON THE POSITION AND
STRENGTH OF THIS WEEKENDS SFC HIGH PRESSURE SYSTEM.
&&
.AVIATION...
VFR FLIGHT CONDITIONS THROUGH TUESDAY WITH A VERY DRY AIRMASS IN
PLACE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TWH/NH
000
FXUS63 KBIS 191001
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
355 AM CST MON JAN 19 2009
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
LATEST WATER VAPOR IMAGERY SHOWS THE UPPER HIGH CENTERED OVER
NORTHERN IDAHO WITH CONTINUED STRONG RIDGING NORTH INTO THE
NORTHWEST TERRITORIES OF CANADA. NORTHWEST WINDS CONTINUE ALOFT
AND AT THE SURFACE OVER NORTH DAKOTA WITH THE UPPER JET SHIFTING
A BIT FURTHER EAST INTO MINNESOTA TODAY.
HOWEVER...WHETHER YOU LOOK AT THE CONSTANT PRESSURE SURFACES/HEIGHTS
ALOFT...OR THE CONSTANT HEIGHT FIELD/MSL PRESSURES...NORTH DAKOTA
REMAINS WEDGED BETWEEN HIGH/LOW PRESSURE RESULTING IN GUSTY
NORTHWEST WINDS. THE FOCUS OF THE STRONGEST WINDS AND THUS WIND
ADVISORY CRITERIA TODAY WILL OCCUR FIRST IN PORTIONS OF OUR FAR
SOUTHWEST ZONES THIS MORNING...THEN OVER OUR SOUTHEAST ZONES THIS
AFTERNOON. ELSEWHERE EXPECT BRISK NORTHWEST WINDS OF 15 TO 30 MPH
BUT FALLING SHORT OF WIND ADVISORY CRITERIA. LATEST MSAS SHOWS
STRONG SURFACE HIGH PRESSURE OVER WESTERN WYOMING AND EASTERN IDAHO
IS NOSING NORTHEAST INTO WESTERN NORTH DAKOTA THIS MORNING. AN UPPER
DISTURBANCE WILL DROP SOUTH NEAR/ALONG OUR WESTERN BORDER THIS
MORNING WITH WEAK UPWARD VERTICAL MOTION AND COLD AIR ADVECTION. THE
SURFACE PRESSURE GRADIENT TIGHTENS OVER OUR FAR SOUTHWEST ZONES
THROUGH 18Z THEN BEGINS TO RELAX SOMEWHAT AS THE SFC HIGH NUDGES
CLOSER AND THE UPPER WAVE DEPARTS. MEANWHILE...A WEAK LOW PRESSURE
AND ASSOCIATED COLD FRONT OVER SOUTHWEST ONTARIO CANADA WILL MOVE
SOUTHEAST TODAY JUST GRAZING OUR FAR SOUTH CENTRAL ZONES. THE
SURFACE PRESSURE GRADIENT ALSO TIGHTENS ENOUGH ALONG WITH WEAK COLD
AIR ADVECTION TO PROMOTE SUSTAINED NORTHWEST WINDS BETWEEN 25 AND 30
MPH WITH GUSTS TO 40 MPH. WINDS WILL SUBSIDE EARLY THIS EVENING.
THERE WILL MOST LIKELY BE SOME BLOWING SNOW IN SPOTS THAT HAVE NOT
RISEN ABOVE FREEZING...BUT DONT THINK ENOUGH TO BRING DOWN
VISIBILITY OVER A WIDESPREAD AREA...THUS WILL ISSUE THE WIND
ADVISORY BUT ALSO MENTION SOME AREAS OF BLOWING SNOW AND LOWER
VISIBILITY AT TIMES.
THE LATEST FOG/STRATUS LOOP SHOWS AN AREA OF STRATUS OVER OUR
SOUTHEAST ZONES ALIGNING NEARLY NORTH TO SOUTH ALONG A STATIONARY
BOUNDARY. THE CLOUDS WILL ERODE FROM WEST TO EAST THIS MORNING...BUT
THE NAM12 925MB MOISTURE FIELD BRINGS ANOTHER SLUG OF STRATUS INTO
THE AREA FROM 18Z-00Z...CURRENTLY OVER LAKE WINNIPEG AND MOVING
SOUTH. THE NAM CAPTURES THIS AREA WELL AND WILL ADJUST SKY COVER.
OTHERWISE/ELSEWHERE EXPECT MOSTLY SUNNY SKIES TODAY WITH
TEMPERATURES A COUPLE DEGREES WARMER THAN SUNDAY. WARM AIR ADVECTION
KICKS IN STRONGLY TONIGHT THROUGH MOST OF TUESDAY RESULTING IN OUR
WARMEST DAY WITH HIGHS IN THE MID/UPPER 30S NORTH AND EAST TO LOWER
50S SOUTHWEST. SOUTH CENTRAL ZONES AROUND 40F OR LOWER 40S FOR HIGHS
TUESDAY. THE UPPER HIGH BEGINS TO DEFLATE WITH HEIGHTS FLATTENING
OUT OVER NORTH DAKOTA AND WEST WEDNESDAY AND WEDNESDAY NIGHT...THUS
WILL BEGIN TO SEE COOLER TEMPERATURES FILTER IN. NO PRECIPITATION
TODAY THROUGH WEDNESDAY NIGHT ACROSS THE CWA.
.LONG TERM...THURSDAY THROUGH MONDAY NIGHT
THE ARRIVAL OF AN ARCTIC HIGH...TO BE PRECEDED BY A PERIOD OF LIGHT
SNOW...WILL BE A BIT SLOWER THAN PREVIOUSLY FORECAST AS WITNESSED BY
THE LATEST RUNS OF THE GFS AND EC. THIS CHANGE IS REFLECTED IN THE
POP AND TEMPERATURE GRIDS. AN EXTENDED PERIOD OF BELOW NORMAL
TEMPERATURES FOLLOWS THE ARRIVAL OF THE ARCTIC HIGH. ADDITIONAL
PRECIPITATION EVENTS MAY ARRIVE EARLY NEXT WEEK WITH THE APPROACH OF
A MODERATELY STRONG SHORT WAVE.
&&
.AVIATION...
AN IFR DECK OF STRATUS WILL CONTINUE TO MOVE THROUGH THE EASTERN
PORTIONS OF OUR FORECAST AREA THIS MORNING. THIS DECK WILL EXIT THE
REGION BY EVENING. GUSTY NORTHWEST SURFACE WINDS OF 20 TO 35 MPH
WILL AFFECT THE SOUTHWEST PART OF THE STATE THIS MORNING...AND THE
SOUTHEAST THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 6 PM CST THIS AFTERNOON FOR
NDZ025-037-047-048-050-051.
WIND ADVISORY FROM 5 AM TO 11 AM MST THIS MORNING FOR NDZ040-043-
044.
&&
$$
KS/RSL
000
FXUS63 KBIS 190136
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
736 PM CST SUN JAN 18 2009
.UPDATE...UPDATE FOR EXPIRING WIND ADVISORY SOUTHWEST. STILL
BREEZY...BUT UNDER WIND ADVISORY CRITERIA.
&&
.PREV DISCUSSION... /ISSUED 315 PM CST SUN JAN 18 2009/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
MAIN FORECAST PROBLEM IN THE SHORT TERM WILL BE TEMPERATURES. MODELS
IN PRETTY GOOD AGREEMENT THROUGH THE SHORT TERM AND WILL USE A BLEND.
CURRENTLY...STRONG GRADIENT BETWEEN LOW OVER THE GREAT LAKES AND
HIGH OVER THE NORTHWEST IS PRODUCING GUSTY NORTHWEST WINDS OVER
SOUTHWEST NORTH DAKOTA. DIK...HEI AND BOWMAN ALL SUSTAINED AROUND 30
MPH AT 1 PM MST. WILL CONTINUE THE WIND ADVISORY UNTIL 5 PM MST.
YESTERDAY WE HAD THE RIGHT IDEA AS FAR AS OVERNIGHT TEMPERATURES BUT
WE WERE JUST NOT GUTSY ENOUGH TO GO SO WARM WITH TEMPERATURES.
CONSEQUENTLY...I WAS WAY TOO COOL WITH OVERNIGHT LOWS. STRAIGHT GFS
MODEL GUIDANCE WAS THE WAY TO GO LAST NIGHT. OUR RECENT WARM SPELL
IS WREAKING HAVOC WITH OUR BIAS CORRECTED MINIMUM TEMPERATURES.
THERE IS A LITTLE COLD ADVECTION IN THE EAST...AS NOTED BY THE
FALLING TEMPERATURES IN JMS AND DVL THIS PAST HOUR...AND THIS COULD
HELP DROP TEMPERATURES IN THE EAST. OVERALL I WOULD EXPECT A
SITUATION SIMILAR TO LAST NIGHT....WITH AT LEAST SOME MID AND UPPER
LEVEL CLOUDINESS HANGING AROUND FOR MOST OF THE NIGHT...AND WINDS
THAT DO NOT DROP LESS THAN AROUND 7 MPH...WOULD EXPECT LOWS TO
REMAIN IN THE 20S...POSSIBLY MID TO UPPER 20S OVER THE WESTERN HALF.
THE EAST WOULD HAVE A BETTER POTENTIAL TO FALL INTO THE TEENS. WILL
TAKE ANOTHER SHOT AND RAISE MIN FORECAST TEMPERATURES A GOOD 5
DEGREES OR SO IN THE WEST.
ON MONDAY...OUR STRONG GRADIENT WINDS CONTINUE AS THE UPPER RIDGE
MEANDERS SLOWLY EASTWARD. STRONGEST SURFACE GRADIENT MOVES ACROSS
CENTRAL NORTH DAKOTA ON MONDAY...BUT WITH SURFACE HIGH PUSHING INTO
THE WEST DURING THE AFTERNOON...THINK WIND ADVISORY POTENTIAL IS
MARGINAL AT BEST. WILL LET THE MID SHIFT TAKE ANOTHER LOOK AND ISSUE
SOMETHING IF NEED BE. SHOULD BE A FEW DEGREES WARMER ON MONDAY AS
WARMER MID LEVEL TEMPERATURES SLOWLY ENCROACH INTO THE REGION.
MONDAY NIGHT WILL BE ANOTHER CHALLENGE WITH TEMPERATURES. STILL
LOOKS LIKE IT WILL BE WARMER THAN GUIDANCE IS INDICATING AS WE NEVER
DO LOSE THE GRADIENT WINDS. WINDS DO APPEAR A BIT LIGHTER AND THIS
WOULD ALLOW A BETTER CHANCE FOR SURFACE WINDS TO DE-COUPLE. COULD BE
A CASE WHERE LOCAL TERRAIN COMES INTO PLAY. ISN AND BIS COULD DROP
OFF BUT WINDIER DIK AND MOT STAY UP. WILL STILL HEDGE A BIT WARMER
MONDAY NIGHT...BUT WILL STICK CLOSER TO GUIDANCE/PERSISTENCE.
TUESDAY LOOKS TO BE THE WARMEST DAY IN THE SHORT TERM...WITH SOME 50
DEGREE TEMPERATURES POSSIBLE IN THE SOUTHWEST. SURFACE TROUGH
TRAVERSES THE CWA...WITH NORTHWEST FLOW BEHIND...SHOULD HELP TO
BRING DOWN THOSE WARM TEMPERATURES ALOFT.
UPPER RIDGE BEGINS TO COLLAPSE ON WEDNESDAY. WE WILL BEGIN TO COOL
DOWN...BUT OVERALL STILL NOT TOO BAD TEMPERATURE WISE. WEDNESDAY
NIGHT...WE WILL REALLY START TO FEEL THE DIFFERENCE AS COLD
ADVECTION BEGINS IN EARNEST. THIS IS THE ONLY PERIOD OF THE SHORT
TERM WITH ANY MENTION OF PRECIPITATION. DUE TO THE STRONG COLD
ADVECTION...MODELS ARE DEPICTING SOME LIGHT QPF SPREADING NORTH TO
SOUTH. PREVIOUS FORECAST HAD A MENTION OF LIGHT SNOW AND THAT STILL
LOOKS GOOD. ADJUSTED AREA JUST A BIT TO FIT WITH SURROUNDING
OFFICES.
LONG TERM...THURSDAY THROUGH SUNDAY...
THE GFS AND ECMWF ARE IN AGREEMENT THURSDAY AND FRIDAY DROPPING AN
ARCTIC HIGH PRESSURE SYSTEM DOWN OVER THE STATE. TEMPERATURES WILL
AGAIN TREND WELL BELOW NORMAL. SHOULD BE A CHANCE OF LIGHT SNOW
WITH THE INITIAL SURGE OF COLD AIR ON THURSDAY...THEN LITTLE CHANCE
THROUGH FRIDAY AND SATURDAY AS THE HIGH PRESSURE SYSTEM SITS OVER
THE STATE. THE GFS AND ECMWF DIVERGE BY SATURDAY AFTERNOON WITH THE
GFS KEEPING AN UPPER LEVEL LOW/TROUGH OVER THE WEST WHILE THE ECMWF
BRINGS AN UPPER LEVEL SHORT WAVE TROUGH OVER THE ROCKIES. THE ECMWF
WILL BRING SNOW AND WARMER WEATHER...WHILE THE GFS WOULD KEEP THE
STATE IN COLD AIR WITH A SYSTEM MOVING THROUGH TO THE SOUTH BRINGING
A SLIGHT CHANCE OF PRECIP TO THE SOUTH HALF OF THE STATE. FOR NOW
WILL TREND WITH THE GFS.
AVIATION...AN BAND OF LOW MVFR CLOUDS HAS MOVED INTO EASTERN NORTH
DAKOTA AND HAVE DROPPED THE CEILINGS IN JAMESTOWN AND DEVILS LAKE TO
ABOUT 15 HUNDRED FT AGL. THE BAND EXTENDS NORTH WELL INTO CANADA
AND HAS SHOWN LITTLE EASTWARD MOVEMENT. EXPECT THE EAST TO REMAIN IN
THE STRATUS THROUGH THE NIGHT. HIGHER CLOUDS COVER THE WEST AND A
WESTERLY SURFACE FLOW SHOULD KEEP CEILINGS VFR THROUGH THE NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
WAA
000
FXUS63 KBIS 182113
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
315 PM CST SUN JAN 18 2009
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
MAIN FORECAST PROBLEM IN THE SHORT TERM WILL BE TEMPERATURES. MODELS
IN PRETTY GOOD AGREEMENT THROUGH THE SHORT TERM AND WILL USE A BLEND.
CURRENTLY...STRONG GRADIENT BETWEEN LOW OVER THE GREAT LAKES AND
HIGH OVER THE NORTHWEST IS PRODUCING GUSTY NORTHWEST WINDS OVER
SOUTHWEST NORTH DAKOTA. DIK...HEI AND BOWMAN ALL SUSTAINED AROUND 30
MPH AT 1 PM MST. WILL CONTINUE THE WIND ADVISORY UNTIL 5 PM MST.
YESTERDAY WE HAD THE RIGHT IDEA AS FAR AS OVERNIGHT TEMPERATURES BUT
WE WERE JUST NOT GUTSY ENOUGH TO GO SO WARM WITH TEMPERATURES.
CONSEQUENTLY...I WAS WAY TOO COOL WITH OVERNIGHT LOWS. STRAIGHT GFS
MODEL GUIDANCE WAS THE WAY TO GO LAST NIGHT. OUR RECENT WARM SPELL
IS WREAKING HAVOC WITH OUR BIAS CORRECTED MINIMUM TEMPERATURES.
THERE IS A LITTLE COLD ADVECTION IN THE EAST...AS NOTED BY THE
FALLING TEMPERATURES IN JMS AND DVL THIS PAST HOUR...AND THIS COULD
HELP DROP TEMPERATURES IN THE EAST. OVERALL I WOULD EXPECT A
SITUATION SIMILAR TO LAST NIGHT....WITH AT LEAST SOME MID AND UPPER
LEVEL CLOUDINESS HANGING AROUND FOR MOST OF THE NIGHT...AND WINDS
THAT DO NOT DROP LESS THAN AROUND 7 MPH...WOULD EXPECT LOWS TO
REMAIN IN THE 20S...POSSIBLY MID TO UPPER 20S OVER THE WESTERN HALF.
THE EAST WOULD HAVE A BETTER POTENTIAL TO FALL INTO THE TEENS. WILL
TAKE ANOTHER SHOT AND RAISE MIN FORECAST TEMPERATURES A GOOD 5
DEGREES OR SO IN THE WEST.
ON MONDAY...OUR STRONG GRADIENT WINDS CONTINUE AS THE UPPER RIDGE
MEANDERS SLOWLY EASTWARD. STRONGEST SURFACE GRADIENT MOVES ACROSS
CENTRAL NORTH DAKOTA ON MONDAY...BUT WITH SURFACE HIGH PUSHING INTO
THE WEST DURING THE AFTERNOON...THINK WIND ADVISORY POTENTIAL IS
MARGINAL AT BEST. WILL LET THE MID SHIFT TAKE ANOTHER LOOK AND ISSUE
SOMETHING IF NEED BE. SHOULD BE A FEW DEGREES WARMER ON MONDAY AS
WARMER MID LEVEL TEMPERATURES SLOWLY ENCROACH INTO THE REGION.
MONDAY NIGHT WILL BE ANOTHER CHALLENGE WITH TEMPERATURES. STILL
LOOKS LIKE IT WILL BE WARMER THAN GUIDANCE IS INDICATING AS WE NEVER
DO LOSE THE GRADIENT WINDS. WINDS DO APPEAR A BIT LIGHTER AND THIS
WOULD ALLOW A BETTER CHANCE FOR SURFACE WINDS TO DE-COUPLE. COULD BE
A CASE WHERE LOCAL TERRAIN COMES INTO PLAY. ISN AND BIS COULD DROP
OFF BUT WINDIER DIK AND MOT STAY UP. WILL STILL HEDGE A BIT WARMER
MONDAY NIGHT...BUT WILL STICK CLOSER TO GUIDANCE/PERSISTENCE.
TUESDAY LOOKS TO BE THE WARMEST DAY IN THE SHORT TERM...WITH SOME 50
DEGREE TEMPERATURES POSSIBLE IN THE SOUTHWEST. SURFACE TROUGH
TRAVERSES THE CWA...WITH NORTHWEST FLOW BEHIND...SHOULD HELP TO
BRING DOWN THOSE WARM TEMPERATURES ALOFT.
UPPER RIDGE BEGINS TO COLLAPSE ON WEDNESDAY. WE WILL BEGIN TO COOL
DOWN...BUT OVERALL STILL NOT TOO BAD TEMPERATURE WISE. WEDNESDAY
NIGHT...WE WILL REALLY START TO FEEL THE DIFFERENCE AS COLD
ADVECTION BEGINS IN EARNEST. THIS IS THE ONLY PERIOD OF THE SHORT
TERM WITH ANY MENTION OF PRECIPITATION. DUE TO THE STRONG COLD
ADVECTION...MODELS ARE DEPICTING SOME LIGHT QPF SPREADING NORTH TO
SOUTH. PREVIOUS FORECAST HAD A MENTION OF LIGHT SNOW AND THAT STILL
LOOKS GOOD. ADJUSTED AREA JUST A BIT TO FIT WITH SURROUNDING
OFFICES.
.LONG TERM...THURSDAY THROUGH SUNDAY...
THE GFS AND ECMWF ARE IN AGREEMENT THURSDAY AND FRIDAY DROPPING AN
ARCTIC HIGH PRESSURE SYSTEM DOWN OVER THE STATE. TEMPERATURES WILL
AGAIN TREND WELL BELOW NORMAL. SHOULD BE A CHANCE OF LIGHT SNOW
WITH THE INITIAL SURGE OF COLD AIR ON THURSDAY...THEN LITTLE CHANCE
THROUGH FRIDAY AND SATURDAY AS THE HIGH PRESSURE SYSTEM SITS OVER
THE STATE. THE GFS AND ECMWF DIVERGE BY SATURDAY AFTERNOON WITH THE
GFS KEEPING AN UPPER LEVEL LOW/TROUGH OVER THE WEST WHILE THE ECMWF
BRINGS AN UPPER LEVEL SHORT WAVE TROUGH OVER THE ROCKIES. THE ECMWF
WILL BRING SNOW AND WARMER WEATHER...WHILE THE GFS WOULD KEEP THE
STATE IN COLD AIR WITH A SYSTEM MOVING THROUGH TO THE SOUTH BRINGING
A SLIGHT CHANCE OF PRECIP TO THE SOUTH HALF OF THE STATE. FOR NOW
WILL TREND WITH THE GFS.
&&
.AVIATION...AN BAND OF LOW MVFR CLOUDS HAS MOVED INTO EASTERN NORTH
DAKOTA AND HAVE DROPPED THE CEILINGS IN JAMESTOWN AND DEVILS LAKE TO
ABOUT 15 HUNDRED FT AGL. THE BAND EXTENDS NORTH WELL INTO CANADA
AND HAS SHOWN LITTLE EASTWARD MOVEMENT. EXPECT THE EAST TO REMAIN IN
THE STRATUS THROUGH THE NIGHT. HIGHER CLOUDS COVER THE WEST AND A
WESTERLY SURFACE FLOW SHOULD KEEP CEILINGS VFR THROUGH THE NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY THROUGH 5 PM MST THIS AFTERNOON FOR
NDZ031>033-040-041-043-044.
&&
$$
TWH/TSW
000
FXUS63 KBIS 181010
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
400 AM CST SUN JAN 18 2009
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...
STRONG UPPER HIGH PRESSURE OVER SOUTHWEST BRITISH COLUMBIA THIS
MORNING WITH ITS RIDGE AXIS REACHING ALL THE WAY INTO THE
NORTHWEST TERRITORIES OF CANADA. THE HIGH WILL GRADUALLY SHIFT
SOUTHEAST INTO IDAHO MONDAY...THEN UTAH AND COLORADO BY TUESDAY.
AS THE CENTER OF THE HIGH AND ITS RIDGE AXIS SHIFT EAST SO WILL
THE UPPER H3 JET WHICH STILL RESIDES OVER NORTH DAKOTA. THE
LATEST WATER VAPOR IMAGERY AND IR SATELLITE LOOP SHOWS AN AREA OF
MAINLY HIGH CLOUDS 15KFT-25KFT MOVING SOUTH FROM CANADA AROUND THE
RIDGE ASSOCIATED WITH A H3 120KT JET. SCT/BKN HIGH CLOUDS FROM
SFC OBS UPSTREAM IN CANADA WILL FILTER THROUGH DURING THE DAY
TODAY AND LATEST RH CROSS SECTIONS REVEAL THAT SCENARIO. THUS SCT
TO BKN HIGH CLOUDS FOR MOST OF THE DAY...STILL ENOUGH INSOLATION
GIVING JUST A COUPLE OF DEGREES OF WARMING THIS AFTERNOON THAN
SATURDAY. WITH THE SLOW SHIFT OF THE UPPER RIDGE...THE PRESSURE
GRADIENT BETWEEN HIGH PRESSURE IN THE WEST AND LOW PRESSURE IN THE
EASTERN GREAT LAKES CONTINUES TO REMAIN IN FLUX AND ANY MINOR
DISTURBANCE OR WEAK FRONT HAS BEEN ABLE TO GENERATE BRISK TO WINDY
CONDITIONS ACROSS OUR CWA. TODAY...A TIGHTENING PRESSURE GRADIENT
WILL DEVELOP OVER OUR SOUTHWESTERN ZONES EMANATING FROM HIGH
PRESSURE OVER IDAHO AND A WEAK LOW DROPPING SOUTH OVER MINNESOTA. THE
STRONGEST WINDS WILL BE FOCUSED OVER OUR FOUR SOUTHWESTERN COUNTIES
OF SLOPE...HETTINGER...BOWMAN...AND ADAMS. BOUNDARY LAYER WINDS
TOP OUT AT 30KT THIS AFTERNOON WITH A SFC REFLECTION OF AROUND
25KT/30 MPH. COLLABORATED WITH NEIGHBORING OFFICES AT UNR AND BYZ
AND DECIDED TO ISSUE A WIND ADVISORY FOR THE COUNTIES MENTIONED
ABOVE FROM 18Z-00Z. BRISK NORTHWEST WINDS OF 15 TO 25 MPH WILL
CONTINUE OVER THE REST OF THE CWA. WARM AIR ADVECTION WILL SLOWLY
CONTINUE TO INCREASE THROUGH MONDAY THEN ACCELERATE GREATLY ON
TUESDAY. CONSEQUENTLY...HIGHS ON MONDAY WILL INCREASE BY A COUPLE
DEGREES AGAIN...THEN TEMPERATURES WILL JUMP SIGNIFICANTLY ON
TUESDAY WITH THIS BEING OUR WARMEST DAY. HIGHS ON TUESDAY WILL
RANGE FROM THE LOWER 30S IN OUR FAR EASTERN ZONES TO THE LOWER 50S
IN OUR SOUTHWESTERN ZONES...WITH HIGH TEMPS IN BETWEEN AND NORTH
OF THIS AREA BETWEEN 35 AND 45 DEGREES. MODELS HAVE BEEN
PERSISTENT WITH ADVERTISING A DISTURBANCE ROTATING DOWN FROM
CANADA AROUND THE RIDGE INTO SOUTH CENTRAL NORTH DAKOTA TUESDAY
AFTERNOON. MIXING WILL BE ENHANCED WITH THIS WAVE RESULTING IN
BRISK CONDITIONS TUESDAY WITH NORTHWEST WINDS OF 15 TO 25 MPH. DRY
TODAY THROUGH TUESDAY NIGHT.
.LONG TERM...WEDNESDAY THROUGH SATURDAY
IN THE LONG TERM WE TRANSITION BACK TO SUB NORMAL TEMPERATURE LEVELS
...BUT WITH LITTLE IN THE WAY OF SNOW.
THE H5 RIDGE BEGINS TO FLATTEN ON WEDNESDAY WHICH WILL STILL BE
MILD...JUST NOT AS MILD AS THE PRECEDING DAY. ON THURSDAY AN H5
TROF DRAPES ACROSS SOUTHERN CANADA...AND WITH IT A 1045MB SURFACE
HIGH INTO ALBERTA. THE PRECEDING COLD FRONT CROSSES ON THURSDAY
WITH COLDER AIR FILTERING BACK IN ON NORTH TO NORTHEAST WINDS.
THE H5 TROF HAS NO SIGNIFICANT SHORT WAVE WITH IT...SO THE EVENT
WILL COME THROUGH WITH FLURRIES AT WORST.
BY FRIDAY NIGHT THE HIGH PUSHES THROUGH WITH RETURN WEST / SOUTHWEST
FLOW. THE REPRIEVE IS BRIEF AS THE NEXT POCKET OF REINFORCING COLD
AIR IS QUICKLY KNOCKING ON THE DOOR.
BOTTOM LINE...TURNING MUCH COLDER BY THURSDAY...AND REMAINING COLD
THROUGH SATURDAY...WITH LITTLE IF ANY SNOW.
&&
.AVIATION...
HIGH PRESSURE AT THE SURFACE TO THE WEST...WITH LOW PRESSURE OVER
THE GREAT LAKES. VFR WEATHER FOR WEST AND CENTRAL NORTH DAKOTA WITH
NORTHWEST WINDS 10 TO 20 KNOTS...AND GUSTS AS HIGH AS 30 KNOTS OVER
THE SOUTHWEST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 11 AM THIS MORNING TO 5 PM MST THIS AFTERNOON
FOR NDZ040-041-043-044.
&&
$$
KS/JPM
000
FXUS63 KBIS 172129
AFDBIS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BISMARCK ND
329 PM CST SAT JAN 17 2009
.SYNOPSIS...
THE DOMINANT HIGH AMPLITUDE RIDGE ALONG THE PACIFIC NORTHWEST COAST
WILL MEANDER EAST INTO IDAHO BY MONDAY...THEN SLOWLY DEFLATE
THROUGH WEDNESDAY. THIS IN RESPONSE TO ANOTHER CHUNK OF ARCTIC AIR
OVER FAR NORTHERN CANADA MOVING SOUTH. THIS AIRMASS LOOKS TO MOVE
INTO NORTH DAKOTA BY THURSDAY OF NEXT WEEK. OTHER THAN SOME FLURRIES
OVER OUR CENTRAL AND EASTERN CWA TONIGHT AND SUNDAY...NO
PRECIPITATION IS EXPECTED THROUGH THE SHORT TERM PERIOD (12Z WED).
BOTH MAXIMUM AND MINIMUM TEMPERATURES WILL REMAIN ABOVE NORMAL
DURING THIS TIME FRAME.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
LATEST MSAS INDICATES A DECENT GRADIENT REMAINS OVER WESTERN AND
CENTRAL NORTH DAKOTA. 2 PM CST OBSERVATIONS INDICATE WINDS AT ALL
FIRST ORDER STATIONS ABOVE 20 MPH. STRONGEST WINDS WERE FROM
MOT-N60-BIS WITH GUSTS UP TO 36 MPH AT MOT. PRESSURE RISES WERE
DIMINISHING OVER THE SOUTHEASTERN CWA...WITH FALLS OVER THE
NORTHWEST. CHANNELED VORTICITY IS PRODUCING CLOUDS AND LIGHT
PRECIPITATION OVER THE EASTERN CWA.
TONIGHT...ANOTHER SHORTWAVE DROPS SOUTH ACROSS EASTERN NORTH DAKOTA
THIS EVENING...WITH NVA OVER CENTRAL AND WESTERN ND. THIS ALSO HELPS
MAINTAIN THE GRADIENT WINDS OVER THE WEST AND CENTRAL...THROUGH
AROUND MIDNIGHT. EXPECT THAT WINDS WILL NOT DROP OFF A LOT LATE THIS
AFTERNOON/EARLY THIS EVENING...AND PROBABLY INCREASE AGAIN...
ESPECIALLY OVER CENTRAL ND THIS EVENING...BEFORE SLOWLY DIMINISHING
AFTER MIDNIGHT.
UNDER ORDINARY CIRCUMSTANCES...WOULD NOT NEED ANY HIGHLIGHTS.
HOWEVER...DUE TO THE EXTENSIVE SNOWPACK...THESE WINDS WHICH ARE ONLY
BORDERLINE ADVISORY CRITERIA...ARE CAUSING SIGNIFICANT TRAVEL
PROBLEMS. DRIFTING SNOW IS CAUSING SOME VISIBILITY PROBLEMS AS
VEHICLE LINE OF SIGHT VISIBILITIES ARE RESTRICTED IN AREAS OF HIGH
DRIFTS AND DEEP SNOWPACK. IN ADDITION...DUE TO OUR WARMER
TEMPERATURES...THIS SNOW IS STICKING TO THE ROADWAYS...PRODUCING
PILLOW DRIFTS...AND BECOMING COMPACTED. THIS IS PRODUCING VERY ICY
CONDITIONS. LAW ENFORCEMENT AND DOT OFFICIALS INDICATE NUMEROUS
ACCIDENTS AND ROLLOVERS ON ND HIGHWAYS TODAY. WITH THE INCREASE IN
WINDS EXPECTED TONIGHT...WITH REDUCED VISIBILITIES EXPECTED AFTER
DARK...WILL CONTINUE THE WINTER WEATHER ADVISORY FOR TRAVELERS DUE
TO THE HAZARDOUS ROAD CONDITIONS MENTIONED EARLIER. WE DO EXPECT
WINDS TO DIMINISH AFTER MIDNIGHT AND MID SHIFT...OR PERHAPS THE
EVENING SHIFT CAN CANCEL THE ADVISORY IF NEEDED.
WINDS MAY BE BREEZY AGAIN...ESPECIALLY IN THE WEST BY SUNDAY
AFTERNOON. BUT OVERALL DO NOT EXPECT THE TRAVEL PROBLEMS THAT WE ARE
SEEING TODAY AS SURFACE GRADIENT IS MUCH MORE RELAXED. WE DO SEE
ANOTHER TIGHTENING ON MONDAY...WITH ANOTHER SHORTWAVE DROPPING SOUTH
SO MONDAY WILL BE BREEZY TO WINDY ONCE AGAIN. HOPEFULLY BY THEN WE
CAN WARM ENOUGH TO SETTLE DOWN THE LOOSE SNOWPACK.
SPEAKING OF /WARM ENOUGH/...TEMPERATURES ACTUALLY DO NOT LOOK WARM
ENOUGH...ESPECIALLY OVERNIGHT LOWS. DID NOT ACTUALLY CHANGE MAX
TEMPERATURES ALL THAT MUCH. DID ADJUST MIN TEMPERATURES UP DUE TO
THE CONTINUED MID LEVEL WARM ADVECTION AND PERSISTENT WINDS.
HAVE KEPT THE SHORT TERM PERIOD DRY...EXCEPT FOR A MENTION OF
FLURRIES TONIGHT...EAST OF A MOT-BIS LINE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
THE UPPER LEVEL RIDGE IS DECIMATED ON WEDNESDAY AS BOTH NORTHERN AND
SOUTHERN STREAM SHORT WAVE ENERGY BREAK IT DOWN. THIS WILL RESULT IN
A RETURN TO COLDER TEMPERATURES ALONG WITH SLIGHT CHANCES FOR SNOW
THROUGH THE EXTENDED. FOR OUR GRIDDED DATABASE...KEPT FRIDAY AND
SATURDAY DRY FOR NOW UNTIL DETAILS BECOME MORE CLEAR. AT THIS TIME
CHANCES FOR A MAJOR STORM ARE LOW AS THE MAIN STORM TRACKS WILL
RESIDE NORTH AND SOUTH OF THE NORTHERN PLAINS. CONFIDENCE IS HIGH
FOR COLDER TEMPERATURES THURSDAY INTO THE WEEKEND...NEAR TO BELOW
NORMAL.
&&
.AVIATION...
VFR FLIGHT CONDITIONS WILL PREVAIL AS ALL WEATHER RELATED PROBLEMS
WILL BE AT GROUND LEVEL THROUGH TONIGHT. THE REGION WILL REMAIN IN
BETWEEN LOW PRESSURE EAST AND HIGH PRESSURE WEST...WHICH WILL RESULT
IN CONTINUED BREEZY NORTHWEST WINDS AND AREAS OF BLOWING SNOW. DO
NOT THINK VISIBILITIES IN BLSN WILL FALL ENOUGH THOUGH TO ADVERSELY
AFFECT AVIATION.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
TWH/NH
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