000
FXUS65 KTFX 201705 AAA
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1015 AM MST TUE JAN 20 2009
.UPDATED FOR AVIATION
.UPDATE...NO GRID OR FORECAST CHANGES MADE THIS MORNING. LARGE DOME
OF HIGH PRESSURE PERSISTS OVER MONTANA. THIS WILL KEEP SKIES MOSTLY
CLEAR WITH ABOVE NORMAL TEMPERATURES EXCEPT FOR PORTIONS OF THE
NORTHEAST ZONES WHERE SNOW COVER WILL KEEP TEMPS NEAR FREEZING.
WARANAUSKAS
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1715Z
STRONG UPPER LEVEL RIDGE WILL START TO BREAK DOWN TODAY WITH
DOWNSLOPE WINDS AROUND 15KTS EXPECTED FOR KCTB..KGTF..AND KHVR.
LIGHT WINDS ARE EXPECTED ELSEWHERE WHICH INCLUDES KHLN..KBZN AND
KLWT. VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
WILLIAMSON DC
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...WILLIAMSON DC
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 201704 AAA
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1015 AM MST TUE JAN 20 2009
.UPDATED FOR AVIATION
.UPDATE...NO GRID OR FORECAST CHANGES MADE THIS MORNING. LARGE DOME
OF HIGH PRESSURE PERSISTS OVER MONTANA. THIS WILL KEEP SKIES MOSTLY
CLEAR WITH ABOVE NORMAL TEMPERATURES EXCEPT FOR PORTIONS OF THE
NORTHEAST ZONES WHERE SNOW COVER WILL KEEP TEMPS NEAR FREEZING.
WARANAUSKAS
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1230Z
STRONG UPPER LEVEL RIDGE WILL START TO BREAK DOWN TODAY WITH
DOWNSLOPE WINDS AROUND 15KTS EXPECTED FOR KCTB..KGTF..AND KHVR.
LIGHT WINDS ARE EXPECTED ELSEWHERE WHICH INCLUDES KHLN..KBZN AND
KLWT. VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
WILLIAMSON DC
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...WILLIAMSON DC
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 201618
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
915 AM MST TUE JAN 20 2009
.UPDATE...NO GRID OR FORECAST CHANGES MADE THIS MORNING. LARGE DOME
OF HIGH PRESSURE PERSISTS OVER MONTANA. THIS WILL KEEP SKIES MOSTLY
CLEAR WITH ABOVE NORMAL TEMPERATURES EXCEPT FOR PORTIONS OF THE
NORTHEAST ZONES WHERE SNOW COVER WILL KEEP TEMPS NEAR FREEZING.
WARANAUSKAS
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1230Z
STRONG UPPER LEVEL RIDGE WILL START TO BREAK DOWN TODAY WITH
DOWNSLOPE WINDS AROUND 15KTS EXPECTED FOR KCTB..KGTF..AND KHVR.
LIGHT WINDS ARE EXPECTED ELSEWHERE WHICH INCLUDES KHLN..KBZN AND
KLWT. SKIES WILL REMAIN MAINLY CLEAR THROUGH THE AFTERNOON AND
EVENING BEFORE HIGH CLOUDS BEGIN TO STREAM INTO THE REGION OVERNIGHT
AHEAD OF OUR NEXT WEATHER SYSTEM WHICH WILL AFFECT US LATER THIS
WEEK. OVERALL...VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE
NORTHERN ROCKIES OVER THE NEXT 24 HOURS. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 201128
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
430 AM MST TUE JAN 20 2009
UPDATED AVIATION DISCUSSION
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1230Z
STRONG UPPER LEVEL RIDGE WILL START TO BREAK DOWN TODAY WITH
DOWNSLOPE WINDS AROUND 15KTS EXPECTED FOR KCTB..KGTF..AND KHVR.
LIGHT WINDS ARE EXPECTED ELSEWHERE WHICH INCLUDES KHLN..KBZN AND
KLWT. SKIES WILL REMAIN MAINLY CLEAR THROUGH THE AFTERNOON AND
EVENING BEFORE HIGH CLOUDS BEGIN TO STREAM INTO THE REGION OVERNIGHT
AHEAD OF OUR NEXT WEATHER SYSTEM WHICH WILL AFFECT US LATER THIS
WEEK. OVERALL...VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE
NORTHERN ROCKIES OVER THE NEXT 24 HOURS. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 201127
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
430 AM MST TUE JAN 20 2009
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1230Z
STRONG UPPER LEVEL RIDGE WILL START TO BREAK DOWN TODAY WITH
DOWNSLOPE WINDS AROUND 15KTS EXPECTED FOR KCTB..KGTF..AND KHVR.
LIGHT WINDS ARE EXPECTED ELSEWHERE WHICH INCLUDES KHLN..KBZN AND
KLWT. SKIES WILL REMAIN MAINLY CLEAR THROUGH THE AFTERNOON AND
EVENING BEFORE HIGH CLOUDS BEGIN TO STREAM INTO THE REGION OVERNIGHT
AHEAD OF OUR NEXT WEATHER SYSTEM WHICH WILL AFFECT US LATER THIS
WEEK. OVERALL...VFR CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE
NORTHERN ROCKIES OVER THE NEXT 24 HOURS. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 201104
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
404 AM MST TUE JAN 20 2009
.DISCUSSION...
TODAY THROUGH THURSDAY...A STRONG UPPER RIDGE OVER THE AREA WILL
CONTINUE TO BRING MILD AND DRY CONDITIONS THROUGH WEDNESDAY. THE
SUBSIDENCE INVERSION OVER THE AREA HAS KEPT SOMEWHAT OF A LID ON
AFTERNOON TEMPERATURES...PARTICULARLY OVER THE NORTHEAST AND OVER
THE VALLEYS OF SOUTHWEST MONTANA. THIS WILL CONTINUE TODAY AND
HAVE TEMPERED TEMPERATURES ACCORDINGLY. THE UPPER RIDGE BREAKS
DOWN THURSDAY AS AN UPPER TROF BEGINS TO CARVE OUT ACROSS SOUTHERN
CANADA. THE RESULTING NORTHWEST FLOW ALOFT WILL BRING MORE
MOISTURE AND INSTABILITY TO THE AREA WITH ISOLATED SNOW SHOWERS
DEVELOPING DURING THE AFTERNOON. TEMPERATURES WILL CONTINUE ABOVE
SEASONAL AVERAGES TODAY AND WEDNESDAY BEFORE COOLING TO NEAR
SEASONAL AVERAGES THURSDAY. EMANUEL
THURSDAY NIGHT THROUGH SUNDAY NIGHT...MEDIUM RANGE MODELS CONTINUING
TO COME IN BETTER AGREEMENT WITH REGARDS TO ARRIVAL OF BACKDOOR COLD
FRONT AND COLD CANADIAN AIR MASS. ONE NEW FEATURE THAT APPEARED BOTH
ON THE 12Z AND 00Z RUNS OF THE GFS IS A MOIST UPPER-LEVEL SHORTWAVE
EXPECTED TO MOVE OVER SOUTHWEST MONTANA. NOT TOO CONFIDENT ON HOW
THAT WILL PLAY OUT SO KEPT POPS IN SLIGHT CHANCE CATEGORY IN THE
VALLEYS AND CHANCE IN THE MOUNTAINS. DESPITE 500-1000MB THICKNESSES
ABOVE 540 OVER SOUTHWEST MONTANA AS THE SHORTWAVE PASSES THROUGH
THURSDAY NIGHT...THERE SHOULD BE ENOUGH COLD AIR TO SUPPORT MAINLY
LIGHT SNOW. MEANWHILE...A BACK DOOR COLD FRONT WILL SLIDE THROUGH
MAJORITY OF CWA THURSDAY NIGHT BEFORE STALLING OVER FAR SOUTHERN
MONTANA WHERE IT WILL INTERACT WITH A MOIST PACIFIC AIRMASS. THE
INTERACTION OF THE MOIST PACIFIC AIR ALONG THE FRONT AND COLD
CANADIAN AIR BEHIND THE FRONT WILL LIKELY GENERATE WIDESPREAD LIGHT
SNOW FOR FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTH-NORTHEAST WINDS
BEHIND THE FRONT MAY ENHANCE MOUNTAIN SNOW DUE TO UPSLOPING. WILL
CONTINUE TO CLOSELY MONITOR THE PROGRESSION OF THIS SYSTEM AS IT
SEEMS HIGHLIGHTS MAY BE A POSSIBILITY LATER THIS WEEK.
COLD CANADIAN AIR MASS AND ASSOCIATED AREA OF HIGH PRESSURE WILL
PUSH INTO NORTHERN MONTANA SATURDAY NIGHT AND SUNDAY PROVIDING DRIER
CONDITIONS OVER NORTHERN AND NORTH-CENTRAL MONTANA. ECMWF A BIT
SLOWER TO CLEAR THINGS OUT SO KEPT SLIGHT CHANCE OF POPS FROM
GTF-LWT ON SOUTH...HOWEVER AM FAVORING THE GFS A BIT MORE SINCE IT
HAS BEEN MORE CONSISTENT. DRAMATICALLY COLDER TEMPERATURES EXPECTED
BEHIND THE FRONT AS WITH TEMPERATURES FALLING 15 TO 20 DEGREES BELOW
AVERAGE OVER NORTH-CENTRAL MONTANA AND AROUND 10 DEGREES BELOW
AVERAGE FOR SOUTHWEST MONTANA. PREVIOUS RUNS WERE INDICATING MORE OF
A SHALLOW ARCTIC AIR MASS MOVING OVER THE STATE...BUT GFS IS HINTING
AT A SHARPER UPPER LEVEL TROUGH AND DEEPER ARCTIC AIR MASS. MLS
MONDAY THROUGH TUESDAY...MODEL DIFFERENCES DURING THIS PERIOD
CONTINUE TO DETRACT FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND
GFS HAVE A LARGE UPPER LEVEL TROUGH CARVED OUT OVER THE U.S. WITH
AN ARCTIC AIRMASS ENTRENCHED OVER THE FORECAST AREA EARLY
SUNDAY...WITH DIFFERENCES IN THE STRENGTH AND TIMING OF THESE
FEATURES. A BLENDED SOLUTION WAS USED WITH THE ARCTIC AIRMASS
BEGINNING TO MOVE OFF TO THE EAST SUNDAY...AS WEAK DOWNSLOPE FLOW
BEGINS TO SET UP ACROSS MOST AREAS. THIS RESULTS IN A GRADUAL
MODERATION OF TEMPERATURES... BUT READINGS WILL STILL BE WELL
BELOW SEASONAL AVERAGES. WITH PATCHY MOISTURE POSSIBLE IN THE
UPPER LEVEL FLOW...KEPT THE POSSIBILITY OF SNOW NEAR CLIMO VALUES
WITH A SLIGHT CHANCE FOR MOST AREAS...EXCEPT FOR A CHANCE OF SNOW
OVER THE MOUNTAINS. EK
&&
.AVIATION...
STRONG UPPER LEVEL RIDGE REMAINS OVER THE NORTHERN ROCKY MOUNTAINS
FOR CONTINUED CLEAR SKIES AND VFR CONDITIONS TONIGHT THROUGH
TUESDAY AFTERNOON. MPJ
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 31 50 26 / 0 0 0 0
CTB 56 30 50 26 / 0 0 10 0
HLN 39 29 48 28 / 0 0 0 10
BZN 43 26 48 24 / 0 0 0 10
WEY 32 -5 32 16 / 0 0 0 10
DLN 45 19 43 24 / 0 0 0 10
HVR 40 19 40 14 / 0 0 0 0
LWT 54 28 49 23 / 0 0 0 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...MPJ
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 200539
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1040 PM MST MON JAN 19 2009
.UPDATE...
TONIGHTS FORECAST REMAINS UNCHANGED. ONLY MINOR TWEAKS TO MINIMUM
TEMPERATURES IN THE SOUTHWEST VALLEYS THAT WERE FALLING CLOSE TO
OR BELOW FORECAST MINS. NO OTHER SIGNIFICANT CHANGES. GUS
&&
.AVIATION...
STRONG UPPER LEVEL RIDGE REMAINS OVER THE NORTHERN ROCKY MOUNTAINS
FOR CONTINUED CLEAR SKIES AND VFR CONDITIONS TONIGHT THROUGH
TUESDAY AFTERNOON. MPJ
&&
.PREV DISCUSSION...
/ISSUED 417 PM MST MON JAN 19 2009/
TODAY THROUGH WEDNESDAY EVENING. QUIET WEATHER CONDITIONS ACROSS MT
THIS AFTN WITH CURRENT SATELLITE IMAGERY SHOWING LITTLE IF ANY CLOUD
COVER ANYWHERE IN THE STATE. HUGE RIDGE OF HIGH PRESSURE AT THE
SURFACE AND ALOFT PRESENTLY CENTERED FROM THE FOUR CORNERS AREA THRU
WESTERN MT TO THE NORTHERN BC/ALB BORDER WILL DRIFT SLOWLY EASTWARD
TODAY AND TOMORROW RESULTING IN CONTINUED FAIR SKIES AND WELL-ABOVE
NORMAL TEMPERATURES OVER MUCH OF CENTRAL AND SOUTHWEST MT. UPPER
RIDGE BEGINS TO FLATTEN OUT ON WED IN RESPONSE TO DEPARTURE OF VERY
DEEP UPPER TROF OVER EASTERN THIRD OF THE US AND APPROACH OF
RELATIVELY WEAK SHORTWAVES ACROSS WESTERN CANADA. REGION WILL SEE
GRADUAL INCREASE IN HIGH CLOUDS BY LATE WED BUT NO PRECIPITATION IS
EXPECTED UNTIL LATER IN THE WEEK. EVEN WITH THE LARGE RIDGE
OVERHEAD...TEMPERATURE FORECASTS REMAIN A CHALLENGE TODAY. POCKETS
OF COLD AIR FROM SNOW COVER IN NORTH CENTRAL ZONES AND COLD AIR
TRAPPED UNDER INVERSIONS IN THE ELEVATED VALLEYS OF THE SOUTHWEST
ZONES IS KEEPING TEMPS NEAR/BELOW FREEZING THERE WHILE THE PLAINS
WARM TO NEAR-RECORD VALUES. MADE ONLY SLIGHT TWEAKS TO PREVIOUS
TEMP GRIDS SINCE MODELS HAVE TRENDED A BIT TOO WARM PAST FEW DAYS.
WARANAUSKAS
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 35 57 30 50 / 0 0 0 0
CTB 31 55 31 47 / 0 0 0 10
HLN 21 44 30 49 / 0 0 0 0
BZN 18 47 26 48 / 0 0 0 0
WEY 7 38 13 34 / 0 0 0 0
DLN 22 47 19 44 / 0 0 0 0
HVR 19 43 20 39 / 0 0 0 0
LWT 29 57 28 49 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GUSTAFSON
LONG TERM...
AVIATION...MPJ
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 200404
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
904 PM MST MON JAN 19 2009
.UPDATE...
TONIGHTS FORECAST REMAINS UNCHANGED. ONLY MINOR TWEAKS TO MINIMUM
TEMPERATURES IN THE SOUTHWEST VALLEYS THAT WERE FALLING CLOSE TO
OR BELOW FORECAST MINS. NO OTHER SIGNIFICANT CHANGES. GUS
&&
.AVIATION...
STRONG UPPER LEVEL RIDGE REMAINS OVER THE NORTHERN ROCKY MOUNTAINS
FOR CONTINUED CLEAR SKIES AND VFR CONDITIONS TONIGHT THROUGH
TUESDAY AFTERNOON. MPJ
&&
.PREV DISCUSSION...
/ISSUED 417 PM MST MON JAN 19 2009/
TODAY THROUGH WEDNESDAY EVENING. QUIET WEATHER CONDITIONS ACROSS MT
THIS AFTN WITH CURRENT SATELLITE IMAGERY SHOWING LITTLE IF ANY CLOUD
COVER ANYWHERE IN THE STATE. HUGE RIDGE OF HIGH PRESSURE AT THE
SURFACE AND ALOFT PRESENTLY CENTERED FROM THE FOUR CORNERS AREA THRU
WESTERN MT TO THE NORTHERN BC/ALB BORDER WILL DRIFT SLOWLY EASTWARD
TODAY AND TOMORROW RESULTING IN CONTINUED FAIR SKIES AND WELL-ABOVE
NORMAL TEMPERATURES OVER MUCH OF CENTRAL AND SOUTHWEST MT. UPPER
RIDGE BEGINS TO FLATTEN OUT ON WED IN RESPONSE TO DEPARTURE OF VERY
DEEP UPPER TROF OVER EASTERN THIRD OF THE US AND APPROACH OF
RELATIVELY WEAK SHORTWAVES ACROSS WESTERN CANADA. REGION WILL SEE
GRADUAL INCREASE IN HIGH CLOUDS BY LATE WED BUT NO PRECIPITATION IS
EXPECTED UNTIL LATER IN THE WEEK. EVEN WITH THE LARGE RIDGE
OVERHEAD...TEMPERATURE FORECASTS REMAIN A CHALLENGE TODAY. POCKETS
OF COLD AIR FROM SNOW COVER IN NORTH CENTRAL ZONES AND COLD AIR
TRAPPED UNDER INVERSIONS IN THE ELEVATED VALLEYS OF THE SOUTHWEST
ZONES IS KEEPING TEMPS NEAR/BELOW FREEZING THERE WHILE THE PLAINS
WARM TO NEAR-RECORD VALUES. MADE ONLY SLIGHT TWEAKS TO PREVIOUS
TEMP GRIDS SINCE MODELS HAVE TRENDED A BIT TOO WARM PAST FEW DAYS.
WARANAUSKAS
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 35 57 30 50 / 0 0 0 0
CTB 31 55 31 47 / 0 0 0 10
HLN 21 44 30 49 / 0 0 0 0
BZN 18 47 26 48 / 0 0 0 0
WEY 7 38 13 34 / 0 0 0 0
DLN 22 47 19 44 / 0 0 0 0
HVR 19 43 20 39 / 0 0 0 0
LWT 29 57 28 49 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GUSTAFSON
LONG TERM...
AVIATION...MPJ
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 192317
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
417 PM MST MON JAN 19 2009
...UPDATE TO AVIATION...
.DISCUSSION...
TODAY THROUGH WEDNESDAY EVENING. QUIET WEATHER CONDITIONS ACROSS MT
THIS AFTN WITH CURRENT SATELLITE IMAGERY SHOWING LITTLE IF ANY CLOUD
COVER ANYWHERE IN THE STATE. HUGE RIDGE OF HIGH PRESSURE AT THE
SURFACE AND ALOFT PRESENTLY CENTERED FROM THE FOUR CORNERS AREA THRU
WESTERN MT TO THE NORTHERN BC/ALB BORDER WILL DRIFT SLOWLY EASTWARD
TODAY AND TOMORROW RESULTING IN CONTINUED FAIR SKIES AND WELL-ABOVE
NORMAL TEMPERATURES OVER MUCH OF CENTRAL AND SOUTHWEST MT. UPPER
RIDGE BEGINS TO FLATTEN OUT ON WED IN RESPONSE TO DEPARTURE OF VERY
DEEP UPPER TROF OVER EASTERN THIRD OF THE US AND APPROACH OF
RELATIVELY WEAK SHORTWAVES ACROSS WESTERN CANADA. REGION WILL SEE
GRADUAL INCREASE IN HIGH CLOUDS BY LATE WED BUT NO PRECIPITATION IS
EXPECTED UNTIL LATER IN THE WEEK. EVEN WITH THE LARGE RIDGE
OVERHEAD...TEMPERATURE FORECASTS REMAIN A CHALLENGE TODAY. POCKETS
OF COLD AIR FROM SNOW COVER IN NORTH CENTRAL ZONES AND COLD AIR
TRAPPED UNDER INVERSIONS IN THE ELEVATED VALLEYS OF THE SOUTHWEST
ZONES IS KEEPING TEMPS NEAR/BELOW FREEZING THERE WHILE THE PLAINS
WARM TO NEAR-RECORD VALUES. MADE ONLY SLIGHT TWEAKS TO PREVIOUS
TEMP GRIDS SINCE MODELS HAVE TRENDED A BIT TOO WARM PAST FEW DAYS.
WARANAUSKAS
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
STRONG UPPER LEVEL RIDGE REMAINS OVER THE NORTHERN ROCKY MOUNTAINS
FOR CONTINUED CLEAR SKIES AND VFR CONDITIONS TONIGHT THROUGH
TUESDAY AFTERNOON. MPJ
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 35 57 30 50 / 0 0 0 0
CTB 31 55 31 47 / 0 0 0 10
HLN 21 44 30 49 / 0 0 0 0
BZN 18 47 26 48 / 0 0 0 0
WEY 7 38 13 34 / 0 0 0 0
DLN 22 47 19 44 / 0 0 0 0
HVR 19 43 20 39 / 0 0 0 0
LWT 29 57 28 49 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WARANAUSKAS
LONG TERM...SYNER/EK
AVIATION...MPJ
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 192113
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
213 PM MST MON JAN 19 2009
.DISCUSSION...
TODAY THROUGH WEDNESDAY EVENING. QUIET WEATHER CONDITIONS ACROSS MT
THIS AFTN WITH CURRENT SATELLITE IMAGERY SHOWING LITTLE IF ANY CLOUD
COVER ANYWHERE IN THE STATE. HUGE RIDGE OF HIGH PRESSURE AT THE
SURFACE AND ALOFT PRESENTLY CENTERED FROM THE FOUR CORNERS AREA THRU
WESTERN MT TO THE NORTHERN BC/ALB BORDER WILL DRIFT SLOWLY EASTWARD
TODAY AND TOMORROW RESULTING IN CONTINUED FAIR SKIES AND WELL-ABOVE
NORMAL TEMPERATURES OVER MUCH OF CENTRAL AND SOUTHWEST MT. UPPER
RIDGE BEGINS TO FLATTEN OUT ON WED IN RESPONSE TO DEPARTURE OF VERY
DEEP UPPER TROF OVER EASTERN THIRD OF THE US AND APPROACH OF
RELATIVELY WEAK SHORTWAVES ACROSS WESTERN CANADA. REGION WILL SEE
GRADUAL INCREASE IN HIGH CLOUDS BY LATE WED BUT NO PRECIPITATION IS
EXPECTED UNTIL LATER IN THE WEEK. EVEN WITH THE LARGE RIDGE
OVERHEAD...TEMPERATURE FORECASTS REMAIN A CHALLENGE TODAY. POCKETS
OF COLD AIR FROM SNOW COVER IN NORTH CENTRAL ZONES AND COLD AIR
TRAPPED UNDER INVERSIONS IN THE ELEVATED VALLEYS OF THE SOUTHWEST
ZONES IS KEEPING TEMPS NEAR/BELOW FREEZING THERE WHILE THE PLAINS
WARM TO NEAR-RECORD VALUES. MADE ONLY SLIGHT TWEAKS TO PREVIOUS
TEMP GRIDS SINCE MODELS HAVE TRENDED A BIT TOO WARM PAST FEW DAYS.
WARANAUSKAS
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1145Z.
VFR CONDITIONS WILL DOMINATE ALL TAF SITES FOR THE NEXT 24 HOURS.
UPPER LEVEL RIDGE AXIS WILL MOVE ACROSS THE CWA AND YIELD LIGHT
WINDS AT ALL SITES...WITH KHVR AND KGTF EXPECTING THE STRONGEST
SUSTAINED WINDS AT AROUND 15 KNOTS. SUK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 35 57 30 50 / 0 0 0 0
CTB 31 55 31 47 / 0 0 0 10
HLN 21 44 30 49 / 0 0 0 0
BZN 18 47 26 48 / 0 0 0 0
WEY 7 38 13 34 / 0 0 0 0
DLN 22 47 19 44 / 0 0 0 0
HVR 19 43 20 39 / 0 0 0 0
LWT 29 57 28 49 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WARANAUSKAS
LONG TERM...SYNER/KURDY
AVIATION...SUK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 191755
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1055 AM MST MON JAN 19 2009
...UPDATE TO AVIATION...
.UPDATE...NO CHANGES MADE TO CURRENT GRIDS OR FORECAST PRODUCTS THIS
MORNING. DEBATED ABOUT TWEAKING HIGH TEMPS DOWN A BIT FOR
TODAY...BUT MODELS CONTINUED TO SHOW SLIGHT WARM AIR ADVECTION THIS
AFTN AND WINDS SHOULD BE REDUCED TODAY AS UPPER RIDGE AXIS MOVES
OVERHEAD WHICH MAY ALLOW FOR MORE WARMING. THUS RECORD HIGHS STILL
POSSIBLE THIS AFTN FROM BROWNING TO GREAT FALLS TO LEWISTOWN.
WARANAUSKAS
.DISCUSSION...
TODAY THROUGH WEDNESDAY...QUIET WEATHER PATTERN WILL CONTINUE
THROUGH MIDWEEK. A STRONG RIDGE ALOFT WILL CONTINUE TO BRING WARM
AND DRY CONDITIONS TO THE AREA. AS THE RIDGE AXIS MOVES EAST OF
THE CONTINENTAL DIVIDE TODAY...AFTERNOON TEMPERATURES WILL
APPROACH RECORD READINGS ACROSS PORTIONS OF NORTH CENTRAL MONTANA.
SNOWPACK ACROSS THE HI-LINE AND COOLER AIR TRAPPED BELOW
SUBSIDENCE INVERSIONS OVER VALLEYS OF SOUTHWEST MONTANA WILL KEEP
TEMPERATURES COOLER IN THOSE AREAS...WITH READINGS LIKELY TO
REMAIN IN THE 30S AND 40S. SURFACE WINDS WILL ALSO REMAIN LIGHT TO
MODERATE. TEMPERATURES WILL CONTINUE ABOVE SEASONAL AVERAGES. EMANUEL
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1145Z.
VFR CONDITIONS WILL DOMINATE ALL TAF SITES FOR THE NEXT 24 HOURS.
UPPER LEVEL RIDGE AXIS WILL MOVE ACROSS THE CWA AND YIELD LIGHT
WINDS AT ALL SITES...WITH KHVR AND KGTF EXPECTING THE STRONGEST
SUSTAINED WINDS AT AROUND 15 KNOTS. SUK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 60 35 57 30 / 0 0 0 0
CTB 60 36 55 31 / 0 0 0 0
HLN 42 27 44 30 / 0 0 0 0
BZN 45 22 47 26 / 0 0 0 0
WEY 38 8 38 17 / 0 0 0 0
DLN 45 24 47 22 / 0 0 0 0
HVR 44 23 43 16 / 0 0 0 0
LWT 58 32 57 28 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WARANAUSKAS
LONG TERM...SUK
AVIATION...SUK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 191622
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
920 AM MST MON JAN 19 2009
.UPDATE...NO CHANGES MADE TO CURRENT GRIDS OR FORECAST PRODUCTS THIS
MORNING. DEBATED ABOUT TWEAKING HIGH TEMPS DOWN A BIT FOR
TODAY...BUT MODELS CONTINUED TO SHOW SLIGHT WARM AIR ADVECTION THIS
AFTN AND WINDS SHOULD BE REDUCED TODAY AS UPPER RIDGE AXIS MOVES
OVERHEAD WHICH MAY ALLOW FOR MORE WARMING. THUS RECORD HIGHS STILL
POSSIBLE THIS AFTN FROM BROWNING TO GREAT FALLS TO LEWISTOWN.
WARANAUSKAS
.DISCUSSION...
TODAY THROUGH WEDNESDAY...QUIET WEATHER PATTERN WILL CONTINUE
THROUGH MIDWEEK. A STRONG RIDGE ALOFT WILL CONTINUE TO BRING WARM
AND DRY CONDITIONS TO THE AREA. AS THE RIDGE AXIS MOVES EAST OF
THE CONTINENTAL DIVIDE TODAY...AFTERNOON TEMPERATURES WILL
APPROACH RECORD READINGS ACROSS PORTIONS OF NORTH CENTRAL MONTANA.
SNOWPACK ACROSS THE HI-LINE AND COOLER AIR TRAPPED BELOW
SUBSIDENCE INVERSIONS OVER VALLEYS OF SOUTHWEST MONTANA WILL KEEP
TEMPERATURES COOLER IN THOSE AREAS...WITH READINGS LIKELY TO
REMAIN IN THE 30S AND 40S. SURFACE WINDS WILL ALSO REMAIN LIGHT TO
MODERATE. TEMPERATURES WILL CONTINUE ABOVE SEASONAL AVERAGES. EMANUEL
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1145Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL OVER THE NEXT 24 HOURS. AS
UPPER-LEVEL RIDGE AXIS MOVES OVER THE AREA...EXPECT WINDS TO STAY
LIGHT AT MAJORITY OF LOCATIONS. TWO EXCEPTIONS ARE AT KHVR AND KGTF
WHERE SOUTHWEST WINDS ARE HOVERING AROUND 15 KTS. IN GENERAL...WEST
TO SOUTHWEST WINDS OF 15 KTS OR LESS ARE EXPECTED ALONG WITH MAINLY
CLEAR SKIES. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 60 35 57 30 / 0 0 0 0
CTB 60 36 55 31 / 0 0 0 0
HLN 42 27 44 30 / 0 0 0 0
BZN 45 22 47 26 / 0 0 0 0
WEY 38 8 38 17 / 0 0 0 0
DLN 45 24 47 22 / 0 0 0 0
HVR 44 23 43 16 / 0 0 0 0
LWT 58 32 57 28 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 191142
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
445 AM MST MON JAN 19 2009
.DISCUSSION...
TODAY THROUGH WEDNESDAY...QUIET WEATHER PATTERN WILL CONTINUE
THROUGH MIDWEEK. A STRONG RIDGE ALOFT WILL CONTINUE TO BRING WARM
AND DRY CONDITIONS TO THE AREA. AS THE RIDGE AXIS MOVES EAST OF
THE CONTINENTAL DIVIDE TODAY...AFTERNOON TEMPERATURES WILL
APPROACH RECORD READINGS ACROSS PORTIONS OF NORTH CENTRAL MONTANA.
SNOWPACK ACROSS THE HI-LINE AND COOLER AIR TRAPPED BELOW
SUBSIDENCE INVERSIONS OVER VALLEYS OF SOUTHWEST MONTANA WILL KEEP
TEMPERATURES COOLER IN THOSE AREAS...WITH READINGS LIKELY TO
REMAIN IN THE 30S AND 40S. SURFACE WINDS WILL ALSO REMAIN LIGHT TO
MODERATE. TEMPERATURES WILL CONTINUE ABOVE SEASONAL AVERAGES. EMANUEL
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 1145Z.
VFR CONDITIONS WILL CONTINUE TO PREVAIL OVER THE NEXT 24 HOURS. AS
UPPER-LEVEL RIDGE AXIS MOVES OVER THE AREA...EXPECT WINDS TO STAY
LIGHT AT MAJORITY OF LOCATIONS. TWO EXCEPTIONS ARE AT KHVR AND KGTF
WHERE SOUTHWEST WINDS ARE HOVERING AROUND 15 KTS. IN GENERAL...WEST
TO SOUTHWEST WINDS OF 15 KTS OR LESS ARE EXPECTED ALONG WITH MAINLY
CLEAR SKIES. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 60 35 57 30 / 0 0 0 0
CTB 60 36 55 31 / 0 0 0 0
HLN 42 27 44 30 / 0 0 0 0
BZN 45 22 47 26 / 0 0 0 0
WEY 38 8 38 17 / 0 0 0 0
DLN 45 24 47 22 / 0 0 0 0
HVR 44 23 43 16 / 0 0 0 0
LWT 58 32 57 28 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/EK
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 191107
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
407 AM MST MON JAN 19 2009
.DISCUSSION...
TODAY THROUGH WEDNESDAY...QUIET WEATHER PATTERN WILL CONTINUE
THROUGH MIDWEEK. A STRONG RIDGE ALOFT WILL CONTINUE TO BRING WARM
AND DRY CONDITIONS TO THE AREA. AS THE RIDGE AXIS MOVES EAST OF
THE CONTINENTAL DIVIDE TODAY...AFTERNOON TEMPERATURES WILL
APPROACH RECORD READINGS ACROSS PORTIONS OF NORTH CENTRAL MONTANA.
SNOWPACK ACROSS THE HI-LINE AND COOLER AIR TRAPPED BELOW
SUBSIDENCE INVERSIONS OVER VALLEYS OF SOUTHWEST MONTANA WILL KEEP
TEMPERATURES COOLER IN THOSE AREAS...WITH READINGS LIKELY TO
REMAIN IN THE 30S AND 40S. SURFACE WINDS WILL ALSO REMAIN LIGHT TO
MODERATE. TEMPERATURES WILL CONTINUE ABOVE SEASONAL AVERAGES. EMANUEL
WEDNESDAY NIGHT THROUGH SATURDAY NIGHT...UPPER-LEVEL RIDGE BEGINS TO
FLATTEN OUT EARLY IN THE PERIOD AND THIS WILL BE THE START OF
PATTERN SHIFT THAT WILL BRING MOIST AND MUCH COOLER CONDITIONS
ACROSS THE AREA. WEST TO NORTHWESTERLY FLOW DEVELOPING THURSDAY WITH
NEAR AVERAGE HIGH TEMPERATURES. GFS IS HINTING AT SOME PRECIP ACROSS
SOUTHWEST MONTANA LATE THURSDAY INTO THURSDAY NIGHT ASSOCIATED WITH
AN UPPER-LEVEL SHORTWAVE SEPARATE OF OUR MAIN CANADIAN COLD
FRONT...NOT CONFIDENT THAT WILL PAN OUT WILL CONTINUE TO MONITOR AND
SEE HOW LATER RUNS HANDLE IT. MEDIUM RANGE MODELS CONTINUE TO BE
CONSISTENTLY INCONSISTENT AND ARE HAVING DIFFICULTY HANDLING THIS
PATTERN CHANGE. WHILE BOTH THE GFS AND ECMWF ARE SIMILAR IN
TIMING...ARRIVAL OF THE FRONT CONTINUES TO BE PUSHED BACK. ONE OTHER
NOTE OF INTEREST IS THAT ECMWF IS BRINGING MORE COLDER AIR INTO THE
AREA THAN PREVIOUS RUNS WHICH IS MORE IN LINE WITH THE GFS. GFS
CONTINUES TO BE THE WETTER AND COLDER SOLUTION AND WANTS TO DEVELOP
A CLOSED LOW OVER THE PACIFIC NORTHWEST WHILE ECMWF HAS SHALLOW
COLD AIR RETREATING ON SATURDAY BEFORE EVEN REACHING SOUTHWEST
MONTANA. LIKE YESTERDAY...WENT WITH A BLEND OF BOTH OF THESE
SOLUTIONS...IF NORTH-NORTHEAST WINDS DEVELOP BEHIND THE FRONT AND
ENOUGH DEEP COLD AIR PUSHES IN...UPSLOPE PRECIPITATION IN THE FORM
OF SNOW WILL BE LIKELY. WITH THE LOSS OF OUR SNOWPACK...IT MAY BE
DIFFICULT FOR DEEP COLD AIR TO DEVELOP OVER THE CWA BUT ANY NEW SNOW
ACCUMULATION MAY CHANGE THAT SO WILL CONTINUE TO MONITOR AND HOPE
MODELS BECOME MORE ALIGNED OVER FURTHER RUNS. FOR NOW...KEPT POPS IN
CHANCE CATEGORY THURSDAY NIGHT AND FRIDAY WITH WELL BELOW AVERAGE
TEMPERATURES EXPECTED FOR FRIDAY AND SATURDAY. MLS
SUNDAY THROUGH MONDAY...MODEL DIFFERENCES DURING THIS PERIOD DETRACT
FROM FORECAST CONFIDENCE. BOTH THE ECMWF AND GFS INDICATE AN ARCTIC
AIRMASS ENTRENCHED OVER THE FORECAST AREA DURING THIS PERIOD...WITH
DIFFERENCES IN THE STRENGTH OF THIS SYSTEM. A BLENDED SOLUTION WAS
USED WITH TEMPERATURES FALLING TO SINGLE DIGITS BELOW ZERO OVER THE
PLAINS AND SINGLE DIGITS ABOVE ZERO OVER THE REST OF THE FORECAST
AREA. KEPT SNOW NEAR CLIMO VALUES WITH A SLIGHT CHANCE FOR MOST
AREAS...EXCEPT FOR A CHANCE OF SNOW OVER THE MOUNTAINS. EK
&&
.AVIATION...
UPDATED 0540Z.
EXPECT VFR CONDITIONS WITH MOSTLY CLEAR SKIES. CONFIDENT THAT WINDS
AT KHLN AND KBZN WILL BE NO MORE THAN A FEW KNOTS. FOR THE TAF SITES
ON THE PLAINS SOUTHWEST TO WEST WINDS OF GENERALLY 15 KTS OR LESS
ARE LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 60 35 57 30 / 0 0 0 0
CTB 60 36 55 31 / 0 0 0 0
HLN 42 27 44 30 / 0 0 0 0
BZN 45 22 47 26 / 0 0 0 0
WEY 38 8 38 17 / 0 0 0 0
DLN 45 24 47 22 / 0 0 0 0
HVR 44 23 43 16 / 0 0 0 0
LWT 58 32 57 28 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...MLS/EK
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 190536
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1040 PM MST SUN JAN 18 2009
.UPDATE...
THE FORECAST LOOKS GOOD FOR TONIGHT. DID MAKE SOME MINOR TWEAKS TO
MINIMUM TEMPERATURES IN AREAS THAT WERE FALLING CLOSE TO OR BELOW
FORECAST MINS. THESE CHANGES WERE OVER THE NORTHEAST...AND SOME OF
THE SOUTHWEST VALLEYS. OTHERWISE NO CHANGES. DB
&&
.AVIATION...
UPDATED 0540Z.
EXPECT VFR CONDITIONS WITH MOSTLY CLEAR SKIES. CONFIDENT THAT WINDS
AT KHLN AND KBZN WILL BE NO MORE THAN A FEW KNOTS. FOR THE TAF SITES
ON THE PLAINS SOUTHWEST TO WEST WINDS OF GENERALLY 15 KTS OR LESS
ARE LIKELY.
&&
.PREV DISCUSSION...
/ISSUED 415 PM MST SUN JAN 18 2009/
TONIGHT THROUGH TUESDAY...THE WEATHER PATTERN WILL REMAIN QUIET
THROUGH TUESDAY. HIGH PRESSURE ALOFT WILL CONTINUE TO MOVE INTO
THE AREA FROM THE WEST...CONTINUING MOSTLY CLEAR SKIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ACROSS MOST AREAS OF
THE TFX CWA THROUGH THE PERIOD...WITH NEAR RECORD HIGH
TEMPERATURES ALONG THE EAST SLOPES OF THE ROCKIES AND ACROSS
CENTRAL MONTANA. HOWEVER...THE SUBSIDENCE FROM THE HIGH PRESSURE
ALOFT IS SUPPRESSING COOLER AIR IN THE VALLEYS OF SOUTHWEST
MONTANA...WHICH WILL KEEP TEMPERATURES THERE CLOSER TO NORMAL. IN
FACT...SOME HIGHER VALLEYS WILL HAVE TEMPERATURES FALLING TO NEAR
ZERO OVERNIGHT. LINGERING SNOWPACK ACROSS HILL AND BLAINE COUNTIES
WILL KEEP TEMPERATURES CLOSER TO NORMAL THERE AS WELL. PATCHY
FREEZING FOG WILL ALSO REMAIN A POSSIBILITY TONIGHT IN SOME OF
THOSE HIGHER SOUTHWEST VALLEYS. TEMPERATURES WILL COOL A FEW
DEGREES ON TUESDAY AS THE HIGH PRESSURE AREA ALOFT BEGINS EXITING
THE AREA.
TEMPERATURES HAVE AND WILL CONTINUE TO ONLY BE WARM ENOUGH TO
PROMOTE MINOR SNOWMELT AT THE LOWER AND MID ELEVATIONS THROUGH
EARLY THIS WEEK. THEREFORE...ELEVATED RIVER AND STREAM LEVELS
REMAIN POSSIBLE...BUT THERE IS LITTLE EXPECTATION FOR HYDROLOGIC
HIGHLIGHTS AT THIS TIME. WILL CONTINUE TO REFER TO THIS IN THE
HAZARDOUS WEATHER OUTLOOK. WILL ALSO CONTINUE TO MENTION THINNING
ICE...AS THIS WILL REMAIN A HAZARD. COULSTON
TUESDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO
DOMINATE WITH MILD TEMPS. PATTERN CHANGE WILL START TO TAKE EFFECT
ON THURSDAY AS AN ARCTIC AIRMASS APPROACHES FROM CANADA. DUE TO
MEDIUM TERM DIFFERENCES IN STRENGTH...WENT WITH A BLEND OF GFS AND
ECMWF. UPGRADED POPS ACROSS THE REGION WHERE NORTH WINDS AND
SATURATED AIR AT 850MB WILL PROMOTE UPSLOPING. COLD AIR APPEARS TO
BE SHALLOW BEHIND THE FRONT SO THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT APPEARS MORE LIKELY INTO THE WEEKEND AT THIS
TIME. EXPECT SEASONAL TEMPS THURSDAY AND SLIGHTLY BELOW AVERAGE
TEMPS ON FRIDAY.
SATURDAY AND SUNDAY...MODELS ARE IN FAIR AGREEMENT WITH A BROAD
LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
TEMPERATURES ARE EXPECTED TO STAY AT OR BELOW SEASONAL AVERAGES
FOR MUCH OF THE REGION. GUS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 59 35 57 / 0 0 0 0
CTB 35 61 36 56 / 0 0 0 0
HLN 24 44 27 45 / 0 0 0 0
BZN 18 44 21 46 / 0 0 0 0
WEY -2 38 2 39 / 0 0 0 0
DLN 20 44 24 46 / 0 0 0 0
HVR 24 46 26 45 / 0 0 0 0
LWT 30 58 31 57 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DB
LONG TERM...GUS
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 190338
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
838 PM MST SUN JAN 18 2009
.UPDATE...
THE FORECAST LOOKS GOOD FOR TONIGHT. DID MAKE SOME MINOR TWEAKS TO
MINIMUM TEMPERATURES IN AREAS THAT WERE FALLING CLOSE TO OR BELOW
FORECAST MINS. THESE CHANGES WERE OVER THE NORTHEAST...AND SOME OF
THE SOUTHWEST VALLEYS. OTHERWISE NO CHANGES. DB
&&
.AVIATION...
UPDATED 2315Z.
EXPECT VFR CONDITIONS WITH ONLY VARIABLE CLOUDINESS ABOVE 25000 FT
MSL. CONFIDENT THAT WINDS AT KHLN AND KBZN WILL BE NO MORE THAN A
FEW KNOTS. OVER THE TAF SITES ON THE PLAINS SOUTHWEST TO WEST WINDS
OF GENERALLY 15 KTS OR LESS ARE LIKELY.
&&
.PREV DISCUSSION...
/ISSUED 415 PM MST SUN JAN 18 2009/
TONIGHT THROUGH TUESDAY...THE WEATHER PATTERN WILL REMAIN QUIET
THROUGH TUESDAY. HIGH PRESSURE ALOFT WILL CONTINUE TO MOVE INTO
THE AREA FROM THE WEST...CONTINUING MOSTLY CLEAR SKIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ACROSS MOST AREAS OF
THE TFX CWA THROUGH THE PERIOD...WITH NEAR RECORD HIGH
TEMPERATURES ALONG THE EAST SLOPES OF THE ROCKIES AND ACROSS
CENTRAL MONTANA. HOWEVER...THE SUBSIDENCE FROM THE HIGH PRESSURE
ALOFT IS SUPPRESSING COOLER AIR IN THE VALLEYS OF SOUTHWEST
MONTANA...WHICH WILL KEEP TEMPERATURES THERE CLOSER TO NORMAL. IN
FACT...SOME HIGHER VALLEYS WILL HAVE TEMPERATURES FALLING TO NEAR
ZERO OVERNIGHT. LINGERING SNOWPACK ACROSS HILL AND BLAINE COUNTIES
WILL KEEP TEMPERATURES CLOSER TO NORMAL THERE AS WELL. PATCHY
FREEZING FOG WILL ALSO REMAIN A POSSIBILITY TONIGHT IN SOME OF
THOSE HIGHER SOUTHWEST VALLEYS. TEMPERATURES WILL COOL A FEW
DEGREES ON TUESDAY AS THE HIGH PRESSURE AREA ALOFT BEGINS EXITING
THE AREA.
TEMPERATURES HAVE AND WILL CONTINUE TO ONLY BE WARM ENOUGH TO
PROMOTE MINOR SNOWMELT AT THE LOWER AND MID ELEVATIONS THROUGH
EARLY THIS WEEK. THEREFORE...ELEVATED RIVER AND STREAM LEVELS
REMAIN POSSIBLE...BUT THERE IS LITTLE EXPECTATION FOR HYDROLOGIC
HIGHLIGHTS AT THIS TIME. WILL CONTINUE TO REFER TO THIS IN THE
HAZARDOUS WEATHER OUTLOOK. WILL ALSO CONTINUE TO MENTION THINNING
ICE...AS THIS WILL REMAIN A HAZARD. COULSTON
TUESDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO
DOMINATE WITH MILD TEMPS. PATTERN CHANGE WILL START TO TAKE EFFECT
ON THURSDAY AS AN ARCTIC AIRMASS APPROACHES FROM CANADA. DUE TO
MEDIUM TERM DIFFERENCES IN STRENGTH...WENT WITH A BLEND OF GFS AND
ECMWF. UPGRADED POPS ACROSS THE REGION WHERE NORTH WINDS AND
SATURATED AIR AT 850MB WILL PROMOTE UPSLOPING. COLD AIR APPEARS TO
BE SHALLOW BEHIND THE FRONT SO THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT APPEARS MORE LIKELY INTO THE WEEKEND AT THIS
TIME. EXPECT SEASONAL TEMPS THURSDAY AND SLIGHTLY BELOW AVERAGE
TEMPS ON FRIDAY.
SATURDAY AND SUNDAY...MODELS ARE IN FAIR AGREEMENT WITH A BROAD
LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
TEMPERATURES ARE EXPECTED TO STAY AT OR BELOW SEASONAL AVERAGES
FOR MUCH OF THE REGION. GUS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 59 35 57 / 0 0 0 0
CTB 35 61 36 56 / 0 0 0 0
HLN 24 44 27 45 / 0 0 0 0
BZN 18 44 21 46 / 0 0 0 0
WEY -2 38 2 39 / 0 0 0 0
DLN 20 44 24 46 / 0 0 0 0
HVR 24 46 26 45 / 0 0 0 0
LWT 30 58 31 57 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DB
LONG TERM...GUS
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 182313
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
415 PM MST SUN JAN 18 2009
.DISCUSSION...
TONIGHT THROUGH TUESDAY...THE WEATHER PATTERN WILL REMAIN QUIET
THROUGH TUESDAY. HIGH PRESSURE ALOFT WILL CONTINUE TO MOVE INTO
THE AREA FROM THE WEST...CONTINUING MOSTLY CLEAR SKIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ACROSS MOST AREAS OF
THE TFX CWA THROUGH THE PERIOD...WITH NEAR RECORD HIGH
TEMPERATURES ALONG THE EAST SLOPES OF THE ROCKIES AND ACROSS
CENTRAL MONTANA. HOWEVER...THE SUBSIDENCE FROM THE HIGH PRESSURE
ALOFT IS SUPPRESSING COOLER AIR IN THE VALLEYS OF SOUTHWEST
MONTANA...WHICH WILL KEEP TEMPERATURES THERE CLOSER TO NORMAL. IN
FACT...SOME HIGHER VALLEYS WILL HAVE TEMPERATURES FALLING TO NEAR
ZERO OVERNIGHT. LINGERING SNOWPACK ACROSS HILL AND BLAINE COUNTIES
WILL KEEP TEMPERATURES CLOSER TO NORMAL THERE AS WELL. PATCHY
FREEZING FOG WILL ALSO REMAIN A POSSIBILITY TONIGHT IN SOME OF
THOSE HIGHER SOUTHWEST VALLEYS. TEMPERATURES WILL COOL A FEW
DEGREES ON TUESDAY AS THE HIGH PRESSURE AREA ALOFT BEGINS EXITING
THE AREA.
TEMPERATURES HAVE AND WILL CONTINUE TO ONLY BE WARM ENOUGH TO
PROMOTE MINOR SNOWMELT AT THE LOWER AND MID ELEVATIONS THROUGH
EARLY THIS WEEK. THEREFORE...ELEVATED RIVER AND STREAM LEVELS
REMAIN POSSIBLE...BUT THERE IS LITTLE EXPECTATION FOR HYDROLOGIC
HIGHLIGHTS AT THIS TIME. WILL CONTINUE TO REFER TO THIS IN THE
HAZARDOUS WEATHER OUTLOOK. WILL ALSO CONTINUE TO MENTION THINNING
ICE...AS THIS WILL REMAIN A HAZARD. COULSTON
TUESDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO
DOMINATE WITH MILD TEMPS. PATTERN CHANGE WILL START TO TAKE EFFECT
ON THURSDAY AS AN ARCTIC AIRMASS APPROACHES FROM CANADA. DUE TO
MEDIUM TERM DIFFERENCES IN STRENGTH...WENT WITH A BLEND OF GFS AND
ECMWF. UPGRADED POPS ACROSS THE REGION WHERE NORTH WINDS AND
SATURATED AIR AT 850MB WILL PROMOTE UPSLOPING. COLD AIR APPEARS TO
BE SHALLOW BEHIND THE FRONT SO THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT APPEARS MORE LIKELY INTO THE WEEKEND AT THIS
TIME. EXPECT SEASONAL TEMPS THURSDAY AND SLIGHTLY BELOW AVERAGE
TEMPS ON FRIDAY.
SATURDAY AND SUNDAY...MODELS ARE IN FAIR AGREEMENT WITH A BROAD
LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
TEMPERATURES ARE EXPECTED TO STAY AT OR BELOW SEASONAL AVERAGES
FOR MUCH OF THE REGION. GUS
&&
.AVIATION...
UPDATED 2315Z.
EXPECT VFR CONDITIONS WITH ONLY VARIABLE CLOUDINESS ABOVE 25000 FT
MSL. CONFIDENT THAT WINDS AT KHLN AND KBZN WILL BE NO MORE THAN A
FEW KNOTS. OVER THE TAF SITES ON THE PLAINS SOUTHWEST TO WEST WINDS
OF GENERALLY 15 KTS OR LESS ARE LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 59 35 57 / 0 0 0 0
CTB 35 61 36 56 / 0 0 0 0
HLN 24 44 27 45 / 0 0 0 0
BZN 18 44 21 46 / 0 0 0 0
WEY -2 38 2 39 / 0 0 0 0
DLN 20 44 24 46 / 0 0 0 0
HVR 24 46 26 45 / 0 0 0 0
LWT 30 58 31 57 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...SYNER/SAUCIER/GUSTAFSON
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 182215
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
315 PM MST SUN JAN 18 2009
.DISCUSSION...
TONIGHT THROUGH TUESDAY...THE WEATHER PATTERN WILL REMAIN QUIET
THROUGH TUESDAY. HIGH PRESSURE ALOFT WILL CONTINUE TO MOVE INTO
THE AREA FROM THE WEST...CONTINUING MOSTLY CLEAR SKIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL ACROSS MOST AREAS OF
THE TFX CWA THROUGH THE PERIOD...WITH NEAR RECORD HIGH
TEMPERATURES ALONG THE EAST SLOPES OF THE ROCKIES AND ACROSS
CENTRAL MONTANA. HOWEVER...THE SUBSIDENCE FROM THE HIGH PRESSURE
ALOFT IS SUPPRESSING COOLER AIR IN THE VALLEYS OF SOUTHWEST
MONTANA...WHICH WILL KEEP TEMPERATURES THERE CLOSER TO NORMAL. IN
FACT...SOME HIGHER VALLEYS WILL HAVE TEMPERATURES FALLING TO NEAR
ZERO OVERNIGHT. LINGERING SNOWPACK ACROSS HILL AND BLAINE COUNTIES
WILL KEEP TEMPERATURES CLOSER TO NORMAL THERE AS WELL. PATCHY
FREEZING FOG WILL ALSO REMAIN A POSSIBILITY TONIGHT IN SOME OF
THOSE HIGHER SOUTHWEST VALLEYS. TEMPERATURES WILL COOL A FEW
DEGREES ON TUESDAY AS THE HIGH PRESSURE AREA ALOFT BEGINS EXITING
THE AREA.
TEMPERATURES HAVE AND WILL CONTINUE TO ONLY BE WARM ENOUGH TO
PROMOTE MINOR SNOWMELT AT THE LOWER AND MID ELEVATIONS THROUGH
EARLY THIS WEEK. THEREFORE...ELEVATED RIVER AND STREAM LEVELS
REMAIN POSSIBLE...BUT THERE IS LITTLE EXPECTATION FOR HYDROLOGIC
HIGHLIGHTS AT THIS TIME. WILL CONTINUE TO REFER TO THIS IN THE
HAZARDOUS WEATHER OUTLOOK. WILL ALSO CONTINUE TO MENTION THINNING
ICE...AS THIS WILL REMAIN A HAZARD. COULSTON
TUESDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE CONTINUES TO
DOMINATE WITH MILD TEMPS. PATTERN CHANGE WILL START TO TAKE EFFECT
ON THURSDAY AS AN ARCTIC AIRMASS APPROACHES FROM CANADA. DUE TO
MEDIUM TERM DIFFERENCES IN STRENGTH...WENT WITH A BLEND OF GFS AND
ECMWF. UPGRADED POPS ACROSS THE REGION WHERE NORTH WINDS AND
SATURATED AIR AT 850MB WILL PROMOTE UPSLOPING. COLD AIR APPEARS TO
BE SHALLOW BEHIND THE FRONT SO THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT APPEARS MORE LIKELY INTO THE WEEKEND AT THIS
TIME. EXPECT SEASONAL TEMPS THURSDAY AND SLIGHTLY BELOW AVERAGE
TEMPS ON FRIDAY.
SATURDAY AND SUNDAY...MODELS ARE IN FAIR AGREEMENT WITH A BROAD
LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
TEMPERATURES ARE EXPECTED TO STAY AT OR BELOW SEASONAL AVERAGES
FOR MUCH OF THE REGION. GUS
&&
.AVIATION...
UPDATED 1724Z.
AN UPPER LEVEL HIGH PRESSURE RIDGE WILL REMAIN OVER THE WESTERN
US THROUGH MONDAY. THIS WILL KEEP THE AIRMASS DRY AND RELATIVELY
WARM WITH MODERATE NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE
GUSTY DURING THE AFTERNOON ACROSS THE PLAINS. VFR CONDITIONS WILL
PREVAIL DURING THE NEXT 24 HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 59 35 57 / 0 0 0 0
CTB 35 61 36 56 / 0 0 0 0
HLN 24 44 27 45 / 0 0 0 0
BZN 18 44 21 46 / 0 0 0 0
WEY -2 38 2 39 / 0 0 0 0
DLN 20 44 24 46 / 0 0 0 0
HVR 24 46 26 45 / 0 0 0 0
LWT 30 58 31 57 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...SYNER/SAUCIER/GUSTAFSON
AVIATION...ZELZER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 181748
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1048 AM MST SUN JAN 18 2009
.UPDATE...
ONLY MINOR UPDATES DONE TO ZONE AND STATE FORECASTS THIS MORNING.
GENERALLY INCREASED HIGH CLOUDINESS ACROSS THE AREA IN THE
FORECAST...ALONG WITH BREEZIER WINDS. TEMPERATURES ARE GENERALLY
RUNNING A FEW DEGREES COOLER THAN PREVIOUSLY EXPECTED AS WELL...SO
HAVE LOWERED HIGHS FOR TODAY BY 3 TO 5 DEGREES. HAVE ALSO ADJUSTED
HEADLINES REGARDING RECORD HIGHS ACCORDINGLY. COULSTON
&&
.AVIATION...
UPDATED 1724Z.
AN UPPER LEVEL HIGH PRESSURE RIDGE WILL REMAIN OVER THE WESTERN
US THROUGH MONDAY. THIS WILL KEEP THE AIRMASS DRY AND RELATIVELY
WARM WITH MODERATE NORTHWEST FLOW ALOFT. SURFACE WINDS WILL BE
GUSTY DURING THE AFTERNOON ACROSS THE PLAINS. VFR CONDITIONS WILL
PREVAIL DURING THE NEXT 24 HOURS.
&&
.PREV DISCUSSION...
/ISSUED 445 AM MST SUN JAN 18 2009/
TODAY THROUGH TUESDAY...BENIGN WEATHER PATTERN WILL CONTINUE. A
STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY EAST
OVER THE AREA THROUGH THE FIRST PART OF THE NEW WEEK. AFTERNOON
TEMPERATURES WILL CLIMB TO NEAR RECORD VALUES OVER A PORTION OF
NORTH CENTRAL MONTANA TODAY AND AGAIN ON MONDAY AS THE RIDGE AXIS
PUSHES THROUGH. THE EXCEPTION TO THE WARM TEMPERATURES WILL BE
THE HIGH VALLEYS OF SOUTHWEST MONTANA WHERE STRONG INVERSIONS
WILL CONTINUE TO INHIBIT TEMPERATURES FROM GETTING TOO WARM.
SURFACE WINDS WILL REMAIN LIGHT AND NO PRECIPITATION IS EXPECTED.
EMANUEL
TUESDAY NIGHT THROUGH FRIDAY NIGHT...UPPER-LEVEL RIDGE AXIS
FINALLY SHIFTS EASTWARD TUESDAY NIGHT WITH WEST WINDS CONTINUING
TO PROMOTE UNSEASONABLY MILD TEMPS ON WEDNESDAY. PATTERN CHANGE
WILL START TO TAKE EFFECT ON THURSDAY AS BACK DOOR COLD FRONT
APPROACHES. MEDIUM RANGE MODELS ARE NOT IN AGREEMENT IN TERMS OF
DEPTH OF COLDER AIR AND PRECIP...HOWEVER BOTH THE GFS AND ECMWF
AGREE ON TIMING OF THIS SYSTEM. DID NOT FAVOR ONE SOLUTION TOO
HEAVILY OVER THE OTHER BUT AM TEMPTED TO LEAN MORE TOWARDS THE
GFS...WHICH IS THE COLDER AND WETTER SOLUTION. DUE TO THE
DISCREPANCIES BETWEEN MODELS...WENT WITH A BLEND OF BOTH AND
EXPECT COOLER BUT SEASONAL TEMPS THURSDAY AND SLIGHTLY BELOW
AVERAGE TEMPS ON FRIDAY DEPENDING ON HOW FAR SOUTH COLD FRONT AND
RESULTING COLD AIR ARRIVE. ON ANOTHER NOTE...IN TERMS OF UPPER-
LEVEL FEATURES...NO NOTABLE SHORTWAVES APPEAR TO BE ACCOMPANYING
THE SURFACE FEATURES AND THIS MAY LIMIT SNOWFALL POTENTIAL DUE TO
LACK OF LIFT. KEPT SLIGHT CHANCE POPS FOR THE VALLEYS ON THURSDAY
WITH CHANCE POPS IN THE MOUNTAINS WHERE NORTH WINDS BEHIND THE
BACK DOOR COLD FRONT WILL PROMOTE UPSLOPING. GFS WANTS TO KEEP
PRECIP ACROSS SOUTHWEST MONTANA ON FRIDAY WITH COLD CANADIAN HIGH
BUILDING FARTHER NORTH WHILE THE ECMWF FAVORS NORTHWEST FLOW AND
SEASONAL TEMPS. SINCE COLDER AIR APPEARS TO BE RATHER SHALLOW
BEHIND THE FRONT AND MAJORITY OF SNOWPACK HAS MELTED...AM LEANING
MORE TOWARDS THE ECMWF WITH DRIER AIR AND NORTHWEST FLOW ALOFT
DOMINATING ACROSS THE CWA. MLS
SATURDAY AND SUNDAY...LATEST MODELS ARE IN FAIR AGREEMENT WITH A
BROAD LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
USED CLIMATOLOGY FOR PRECIPITATION THROUGH THE PERIOD.
TEMPERATURES ARE EXPECTED TO FALL WELL BELOW SEASONAL AVERAGES
FOR MUCH OF THE REGION. SAUCIER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 55 33 61 31 / 0 0 0 0
CTB 55 35 55 33 / 0 0 0 0
HLN 45 28 45 28 / 0 0 0 0
BZN 40 21 50 25 / 0 0 0 0
WEY 30 15 41 20 / 0 0 0 0
DLN 37 21 50 24 / 0 0 0 0
HVR 42 20 40 18 / 0 0 0 0
LWT 51 32 60 30 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON/EMANUEL
LONG TERM...SYNER/SAUCIER
AVIATION...ZELZER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 181143
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
445 AM MST SUN JAN 18 2009
.DISCUSSION...
TODAY THROUGH TUESDAY...BENIGN WEATHER PATTERN WILL CONTINUE.
A STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY EAST
OVER THE AREA THROUGH THE FIRST PART OF THE NEW WEEK. AFTERNOON
TEMPERATURES WILL CLIMB TO NEAR RECORD VALUES OVER A PORTION OF
NORTH CENTRAL MONTANA TODAY AND AGAIN ON MONDAY AS THE RIDGE AXIS
PUSHES THROUGH. THE EXCEPTION TO THE WARM TEMPERATURES WILL BE THE
HIGH VALLEYS OF SOUTHWEST MONTANA WHERE STRONG INVERSIONS WILL
CONTINUE TO INHIBIT TEMPERATURES FROM GETTING TOO WARM. SURFACE
WINDS WILL REMAIN LIGHT AND NO PRECIPITATION IS EXPECTED. EMANUEL
TUESDAY NIGHT THROUGH FRIDAY NIGHT...UPPER-LEVEL RIDGE AXIS FINALLY
SHIFTS EASTWARD TUESDAY NIGHT WITH WEST WINDS CONTINUING TO PROMOTE
UNSEASONABLY MILD TEMPS ON WEDNESDAY. PATTERN CHANGE WILL START TO
TAKE EFFECT ON THURSDAY AS BACK DOOR COLD FRONT APPROACHES. MEDIUM
RANGE MODELS ARE NOT IN AGREEMENT IN TERMS OF DEPTH OF COLDER AIR
AND PRECIP...HOWEVER BOTH THE GFS AND ECMWF AGREE ON TIMING OF THIS
SYSTEM. DID NOT FAVOR ONE SOLUTION TOO HEAVILY OVER THE OTHER BUT
AM TEMPTED TO LEAN MORE TOWARDS THE GFS...WHICH IS THE COLDER AND
WETTER SOLUTION. DUE TO THE DISCREPANCIES BETWEEN MODELS...WENT WITH
A BLEND OF BOTH AND EXPECT COOLER BUT SEASONAL TEMPS THURSDAY AND
SLIGHTLY BELOW AVERAGE TEMPS ON FRIDAY DEPENDING ON HOW FAR SOUTH
COLD FRONT AND RESULTING COLD AIR ARRIVE. ON ANOTHER NOTE...IN
TERMS OF UPPER-LEVEL FEATURES...NO NOTABLE SHORTWAVES APPEAR TO BE
ACCOMPANYING THE SURFACE FEATURES AND THIS MAY LIMIT SNOWFALL
POTENTIAL DUE TO LACK OF LIFT. KEPT SLIGHT CHANCE POPS FOR THE
VALLEYS ON THURSDAY WITH CHANCE POPS IN THE MOUNTAINS WHERE NORTH
WINDS BEHIND THE BACK DOOR COLD FRONT WILL PROMOTE UPSLOPING. GFS
WANTS TO KEEP PRECIP ACROSS SOUTHWEST MONTANA ON FRIDAY WITH COLD
CANADIAN HIGH BUILDING FARTHER NORTH WHILE THE ECMWF FAVORS
NORTHWEST FLOW AND SEASONAL TEMPS. SINCE COLDER AIR APPEARS TO BE
RATHER SHALLOW BEHIND THE FRONT AND MAJORITY OF SNOWPACK HAS
MELTED...AM LEANING MORE TOWARDS THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT DOMINATING ACROSS THE CWA. MLS
SATURDAY AND SUNDAY...LATEST MODELS ARE IN FAIR AGREEMENT WITH A
BROAD LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
USED CLIMATOLOGY FOR PRECIPITATION THROUGH THE PERIOD. TEMPERATURES
ARE EXPECTED TO FALL WELL BELOW SEASONAL AVERAGES FOR MUCH OF THE
REGION. SAUCIER
&&
.AVIATION...
UPDATED 1145Z.
SCATTERED TO BROKEN HIGH CLOUDS ABOVE 15000 FT MSL ARE ROTATING
THROUGH NORTH-CENTRAL MONTANA AS STRONG UPPER-LEVEL RIDGE REMAINS IN
PLACE OVER THE WESTERN U.S. VERY LIGHT TO CALM WINDS EXPECTED AT
KHLN AND KBZN WITH 5 TO 15 KT WINDS ELSEWHERE AT KGTF..KCTB..KHVR
AND KLWT AND WIND DIRECTIONS FLUCTUATING FROM WEST TO SOUTHWEST.
CLEAR TO MAINLY CLEAR SKIES WILL CONTINUE TO DOMINATE THROUGH THE
PERIOD WITH VFR CONDITIONS PERSISTING AS WELL OVER THE NEXT 24
HOURS. MLS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 58 33 61 31 / 0 0 0 0
CTB 58 35 55 33 / 0 0 0 0
HLN 43 28 45 28 / 0 0 0 0
BZN 45 21 50 25 / 0 0 0 0
WEY 38 15 41 20 / 0 0 0 0
DLN 41 21 50 24 / 0 0 0 0
HVR 42 20 40 18 / 0 0 0 0
LWT 56 32 60 30 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/SAUCIER
AVIATION...SYNER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 181058
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
358 AM MST SUN JAN 18 2009
.DISCUSSION...
TODAY THROUGH TUESDAY...BENIGN WEATHER PATTERN WILL CONTINUE.
A STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO MOVE SLOWLY EAST
OVER THE AREA THROUGH THE FIRST PART OF THE NEW WEEK. AFTERNOON
TEMPERATURES WILL CLIMB TO NEAR RECORD VALUES OVER A PORTION OF
NORTH CENTRAL MONTANA TODAY AND AGAIN ON MONDAY AS THE RIDGE AXIS
PUSHES THROUGH. THE EXCEPTION TO THE WARM TEMPERATURES WILL BE THE HIGH
VALLEYS OF SOUTHWEST MONTANA WHERE STRONG INVERSIONS WILL CONTINUE
TO INHIBIT TEMPERATURES FROM GETTING TOO WARM. SURFACE WINDS WILL
REMAIN LIGHT AND NO PRECIPITATION IS EXPECTED. EMANUEL
TUESDAY NIGHT THROUGH FRIDAY NIGHT...UPPER-LEVEL RIDGE AXIS FINALLY
SHIFTS EASTWARD TUESDAY NIGHT WITH WEST WINDS CONTINUING TO PROMOTE
UNSEASONABLY MILD TEMPS ON WEDNESDAY. PATTERN CHANGE WILL START TO
TAKE EFFECT ON THURSDAY AS BACK DOOR COLD FRONT APPROACHES. MEDIUM
RANGE MODELS ARE NOT IN AGREEMENT IN TERMS OF DEPTH OF COLDER AIR
AND PRECIP...HOWEVER BOTH THE GFS AND ECMWF AGREE ON TIMING OF THIS
SYSTEM. DID NOT FAVOR ONE SOLUTION TOO HEAVILY OVER THE OTHER BUT
AM TEMPTED TO LEAN MORE TOWARDS THE GFS...WHICH IS THE COLDER AND
WETTER SOLUTION. DUE TO THE DISCREPANCIES BETWEEN MODELS...WENT WITH
A BLEND OF BOTH AND EXPECT COOLER BUT SEASONAL TEMPS THURSDAY AND
SLIGHTLY BELOW AVERAGE TEMPS ON FRIDAY DEPENDING ON HOW FAR SOUTH
COLD FRONT AND RESULTING COLD AIR ARRIVE. ON ANOTHER NOTE...IN
TERMS OF UPPER-LEVEL FEATURES...NO NOTABLE SHORTWAVES APPEAR TO BE
ACCOMPANYING THE SURFACE FEATURES AND THIS MAY LIMIT SNOWFALL
POTENTIAL DUE TO LACK OF LIFT. KEPT SLIGHT CHANCE POPS FOR THE
VALLEYS ON THURSDAY WITH CHANCE POPS IN THE MOUNTAINS WHERE NORTH
WINDS BEHIND THE BACK DOOR COLD FRONT WILL PROMOTE UPSLOPING. GFS
WANTS TO KEEP PRECIP ACROSS SOUTHWEST MONTANA ON FRIDAY WITH COLD
CANADIAN HIGH BUILDING FARTHER NORTH WHILE THE ECMWF FAVORS
NORTHWEST FLOW AND SEASONAL TEMPS. SINCE COLDER AIR APPEARS TO BE
RATHER SHALLOW BEHIND THE FRONT AND MAJORITY OF SNOWPACK HAS
MELTED...AM LEANING MORE TOWARDS THE ECMWF WITH DRIER AIR AND
NORTHWEST FLOW ALOFT DOMINATING ACROSS THE CWA.
SATURDAY AND SUNDAY...LATEST MODELS ARE IN FAIR AGREEMENT WITH A
BROAD LOW PRESSURE TROUGH MOVING THROUGH THE PACIFIC NORTHWEST.
USED CLIMATOLOGY FOR PRECIPITATION THROUGH THE PERIOD. TEMPERATURES
ARE EXPECTED TO FALL WELL BELOW SEASONAL AVERAGES FOR MUCH OF THE
REGION. SAUCIER
&&
.AVIATION...
UPDATED 0530Z.
EXPECT VFR CONDITIONS WITH ONLY SOME CLOUDS ABOVE 25000 FT MSL FROM
TIME TO TIME. FEEL PRETTY GOOD ABOUT FORECAST WIND SPEEDS AND
DIRECTIONS. AM CONFIDENT IN NEARLY CALM WINDS AT KHLN AND KBZN.
EXPECT WIND DIRECTIONS TO GENERALLY BE WITHIN 30 DEGREES OF THOSE
FORECAST AND WIND SPEEDS TO GENERALLY BE WITHIN A FEW KNOTS OF THOSE
FORECAST. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 58 33 61 31 / 0 0 0 0
CTB 58 35 55 33 / 0 0 0 0
HLN 43 28 45 28 / 0 0 0 0
BZN 45 21 50 25 / 0 0 0 0
WEY 38 15 41 20 / 0 0 0 0
DLN 41 21 50 24 / 0 0 0 0
HVR 42 20 40 18 / 0 0 0 0
LWT 56 32 60 30 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...EMANUEL
LONG TERM...SYNER/SAUCIER
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 180527
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1030 PM MST SAT JAN 17 2009
.UPDATE...
QUIET WEATHER REGIME EXISTS ACROSS THE FORECAST AREA AS A STRONG
RIDGE OF HIGH PRESSURE ALOFT BUILDS EAST INTO THE REGION. SKIES ARE
GENERALLY CLEAR EXCEPT FOR A DISSIPATING AREA OF THIN HIGH CLOUDS
DROPPING SOUTH THROUGH CENTRAL AND EASTERN MT THIS EVENING.
TEMPERATURES WILL REMAIN RELATIVELY MILD FOR THIS TIME OF YEAR ALONG
THE EAST SLOPES OF THE ROCKIES WHERE DOWNSLOPE WINDS AT 10 TO 20 MPH
WILL PERSIST THROUGH THE NIGHT. ELSEWHERE...LIGHT WINDS WILL ALLOW
TEMPS TO FALL INTO THE 20S OR COLDER. STRONG INVERSIONS HAVE
DEVELOPED IN SOME OF THE HIGHER SW MT VALLEYS INCLUDING THE WEST
YELLOWSTONE...LAKEVIEW AREA AND THE BIG HOLE VALLEY...WHERE TEMPS
WILL FALL TO ZERO OR LOWER. THESE SAME COLDER HIGH VALLEYS WILL
LIKELY SEE SOME FOG DEVELOPMENT TONIGHT AS WELL. CURRENT FORECAST
HAS ALL OF THIS HANDLED WELL WITH NO UPDATES NEEDED THIS EVENING.
HOENISCH
&&
.AVIATION...
UPDATED 0530Z.
EXPECT VFR CONDITIONS WITH ONLY SOME CLOUDS ABOVE 25000 FT MSL FROM
TIME TO TIME. FEEL PRETTY GOOD ABOUT FORECAST WIND SPEEDS AND
DIRECTIONS. AM CONFIDENT IN NEARLY CALM WINDS AT KHLN AND KBZN.
EXPECT WIND DIRECTIONS TO GENERALLY BE WITHIN 30 DEGREES OF THOSE
FORECAST AND WIND SPEEDS TO GENERALLY BE WITHIN A FEW KNOTS OF THOSE
FORECAST. BLANK
&&
.PREV DISCUSSION...
/ISSUED 410 PM MST SAT JAN 17 2009/
TONIGHT THROUGH MONDAY...THE QUIET WEATHER PATTERN WILL PERSIST
ACROSS THE TFX CWA THROUGH MONDAY. HIGH PRESSURE ALOFT WILL BUILD
INTO THE AREA FROM THE WEST...FOR A CONTINUED DRY BUT DECREASING
NORTHERLY FLOW ALOFT. ONLY LIGHT WESTERLY SURFACE WINDS WILL
PREVAIL THROUGH THE PERIOD. PATCHY FREEZING FOG WILL DEVELOP IN
THE VALLEYS OF FAR SOUTHWEST MONTANA AGAIN TONIGHT AND SUNDAY
NIGHT...AS THE VALLEY INVERSIONS REMAIN IN PLACE THERE. THE CLEAR
SKIES AND RISING HEIGHTS ALOFT WILL BRING WARMING TEMPERATURES TO
THE AREA THROUGH THE PERIOD AS WELL. TEMPERATURES ON SUNDAY WILL
GENERALLY WARM INTO THE MID 40S TO UPPER 50S...WHICH WILL BE NEAR
RECORD HIGH LEVELS FOR MOST AREAS. TEMPERATURES ON MONDAY WILL
WARM FURTHER INTO THE UPPER 40S TO NEAR 60...WHICH AGAIN WILL BE
NEAR OR AT RECORD LEVELS. HOWEVER...A POCKET OF COLD AIR WILL BE
SLOWER TO ERODE ACROSS HILL AND BLAINE COUNTIES...SO WILL GO WITH
SLIGHTLY COOLER TEMPERATURES THERE. WHERE THERE ARE INVERSIONS IN
THE SOUTHWEST VALLEYS...TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW NORMAL AS WELL.
THE WARMING TEMPERATURES WILL ALSO CAUSE INCREASED SNOWMELT AT THE
LOWER AND MID ELEVATIONS THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
THIS WILL CAUSE RIVER AND STREAM LEVELS TO RISE SOMEWHAT.
HOWEVER...TEMPERATURES WILL COOL TO NEAR TO BELOW FREEZING AT
NIGHT...WHICH WILL HINDER SNOWMELT THEN. ALSO...THE WARMING
TEMPERATURES WILL CAUSE AREAS OF ICE BREAKUP...WHICH MAY LEAD TO
LOCALIZED ICE JAMS. ALTHOUGH THERE IS NO SIGN OF RISING RIVER OR
STREAM LEVELS YET...THE POTENTIAL FOR IT WILL CONTINUE INTO EARLY
NEXT WEEK AND THE SITUATION WILL CONTINUE TO BE MONITORED FOR
POSSIBLE HYDROLOGIC STATEMENTS. COULSTON
TUESDAY THROUGH THURSDAY NIGHT...A BROAD UPPER RIDGE REMAINS OVER
THE AREA TO START THE PERIOD BUT 500MB HEIGHTS BEGIN TO FALL WED
NIGHT AS AN UPPER TROF MOVES IN OVER THE WESTERN US AND CANADA
COAST. A WEAK SHORT WAVE WILL TRANSIT THE AREA THURSDAY NIGHT
BRINGING MOISTURE AND THE CHANCE FOR LIGHT SNOW INTO FRIDAY
MORNING. TEMPERATURES WILL COOL THROUGH THE PERIOD. HIGH TEMPS
WILL BE ABOVE SEASONAL AVERAGES TO START THE PERIOD BUT FALL TO
NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES BY THURSDAY.
FRIDAY AND SATURDAY...GENERAL NORTHWEST FLOW OVER MONTANA IS
EXPECTED TO BRING COOLER AIR FROM CANADA BACK TO THE REGION.
TEMPERATURES SHOULD DROP BACK TO SEASONAL AVERAGES FOR MUCH
OF THE AREA. AT THIS POINT A SLIGHT CHANCE FOR SNOW SHOWERS
SATURDAY FOR THE MOUNTAINS ALONG THE DIVIDE AND CENTRAL PLAINS.
GUS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 58 34 60 / 0 0 0 0
CTB 33 58 35 61 / 0 0 0 0
HLN 24 49 28 52 / 0 0 0 0
BZN 16 47 19 46 / 0 0 0 0
WEY 3 36 7 41 / 0 0 0 0
DLN 21 45 23 48 / 0 0 0 0
HVR 16 44 23 50 / 0 0 0 0
LWT 26 56 31 58 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...EMANUEL/GUSTAFSON
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 180357
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
857 PM MST SAT JAN 17 2009
.UPDATE...
QUIET WEATHER REGIME EXISTS ACROSS THE FORECAST AREA AS A STRONG RIDGE
OF HIGH PRESSURE ALOFT BUILDS EAST INTO THE REGION. SKIES ARE GENERALLY
CLEAR EXCEPT FOR A DISSIPATING AREA OF THIN HIGH CLOUDS DROPPING SOUTH
THROUGH CENTRAL AND EASTERN MT THIS EVENING. TEMPERATURES WILL REMAIN
RELATIVELY MILD FOR THIS TIME OF YEAR ALONG THE EAST SLOPES OF THE
ROCKIES WHERE DOWNSLOPE WINDS AT 10 TO 20 MPH WILL PERSIST THROUGH
THE NIGHT. ELSEWHERE...LIGHT WINDS WILL ALLOW TEMPS TO FALL INTO THE
20S OR COLDER. STRONG INVERSIONS HAVE DEVELOPED IN SOME OF THE HIGHER
SW MT VALLEYS INCLUDING THE WEST YELLOWSTONE...LAKEVIEW AREA AND THE
BIG HOLE VALLEY...WHERE TEMPS WILL FALL TO ZERO OR LOWER. THESE SAME
COLDER HIGH VALLEYS WILL LIKELY SEE SOME FOG DEVELOPMENT TONIGHT AS
WELL. CURRENT FORECAST HAS ALL OF THIS HANDLED WELL WITH NO UPDATES
NEEDED THIS EVENING. HOENISCH
&&
.AVIATION...
UPDATED 2310Z.
EXPECT CLEAR SKIES AT KBZN/KGTF/KHLN/KCTB WITH ONLY SOME CLOUDS
ABOVE 25000 FT MSL FROM TIME TO TIME AT KHVR AND KLWT. FEEL PRETTY
GOOD ABOUT FORECAST WIND SPEEDS AND DIRECTIONS. AM CONFIDENT
IN NEARLY CALM WINDS AT KHLN AND KBZN. EXPECT WIND DIRECTIONS TO
GENERALLY BE WITHIN 30 DEGREES OF THOSE FORECAST AND WIND SPEEDS TO
GENERALLY BE WITHIN A FEW KNOTS OF THOSE FORECAST. BLANK
&&
.PREV DISCUSSION...
/ISSUED 410 PM MST SAT JAN 17 2009/
TONIGHT THROUGH MONDAY...THE QUIET WEATHER PATTERN WILL PERSIST
ACROSS THE TFX CWA THROUGH MONDAY. HIGH PRESSURE ALOFT WILL BUILD
INTO THE AREA FROM THE WEST...FOR A CONTINUED DRY BUT DECREASING
NORTHERLY FLOW ALOFT. ONLY LIGHT WESTERLY SURFACE WINDS WILL
PREVAIL THROUGH THE PERIOD. PATCHY FREEZING FOG WILL DEVELOP IN
THE VALLEYS OF FAR SOUTHWEST MONTANA AGAIN TONIGHT AND SUNDAY
NIGHT...AS THE VALLEY INVERSIONS REMAIN IN PLACE THERE. THE CLEAR
SKIES AND RISING HEIGHTS ALOFT WILL BRING WARMING TEMPERATURES TO
THE AREA THROUGH THE PERIOD AS WELL. TEMPERATURES ON SUNDAY WILL
GENERALLY WARM INTO THE MID 40S TO UPPER 50S...WHICH WILL BE NEAR
RECORD HIGH LEVELS FOR MOST AREAS. TEMPERATURES ON MONDAY WILL
WARM FURTHER INTO THE UPPER 40S TO NEAR 60...WHICH AGAIN WILL BE
NEAR OR AT RECORD LEVELS. HOWEVER...A POCKET OF COLD AIR WILL BE
SLOWER TO ERODE ACROSS HILL AND BLAINE COUNTIES...SO WILL GO WITH
SLIGHTLY COOLER TEMPERATURES THERE. WHERE THERE ARE INVERSIONS IN
THE SOUTHWEST VALLEYS...TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW NORMAL AS WELL.
THE WARMING TEMPERATURES WILL ALSO CAUSE INCREASED SNOWMELT AT THE
LOWER AND MID ELEVATIONS THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
THIS WILL CAUSE RIVER AND STREAM LEVELS TO RISE SOMEWHAT.
HOWEVER...TEMPERATURES WILL COOL TO NEAR TO BELOW FREEZING AT
NIGHT...WHICH WILL HINDER SNOWMELT THEN. ALSO...THE WARMING
TEMPERATURES WILL CAUSE AREAS OF ICE BREAKUP...WHICH MAY LEAD TO
LOCALIZED ICE JAMS. ALTHOUGH THERE IS NO SIGN OF RISING RIVER OR
STREAM LEVELS YET...THE POTENTIAL FOR IT WILL CONTINUE INTO EARLY
NEXT WEEK AND THE SITUATION WILL CONTINUE TO BE MONITORED FOR
POSSIBLE HYDROLOGIC STATEMENTS. COULSTON
TUESDAY THROUGH THURSDAY NIGHT...A BROAD UPPER RIDGE REMAINS OVER
THE AREA TO START THE PERIOD BUT 500MB HEIGHTS BEGIN TO FALL WED
NIGHT AS AN UPPER TROF MOVES IN OVER THE WESTERN US AND CANADA
COAST. A WEAK SHORT WAVE WILL TRANSIT THE AREA THURSDAY NIGHT
BRINGING MOISTURE AND THE CHANCE FOR LIGHT SNOW INTO FRIDAY
MORNING. TEMPERATURES WILL COOL THROUGH THE PERIOD. HIGH TEMPS
WILL BE ABOVE SEASONAL AVERAGES TO START THE PERIOD BUT FALL TO
NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES BY THURSDAY.
FRIDAY AND SATURDAY...GENERAL NORTHWEST FLOW OVER MONTANA IS
EXPECTED TO BRING COOLER AIR FROM CANADA BACK TO THE REGION.
TEMPERATURES SHOULD DROP BACK TO SEASONAL AVERAGES FOR MUCH
OF THE AREA. AT THIS POINT A SLIGHT CHANCE FOR SNOW SHOWERS
SATURDAY FOR THE MOUNTAINS ALONG THE DIVIDE AND CENTRAL PLAINS.
GUS
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 58 34 60 / 0 0 0 0
CTB 33 58 35 61 / 0 0 0 0
HLN 24 49 28 52 / 0 0 0 0
BZN 16 47 19 46 / 0 0 0 0
WEY 3 36 7 41 / 0 0 0 0
DLN 21 45 23 48 / 0 0 0 0
HVR 16 44 23 50 / 0 0 0 0
LWT 26 56 31 58 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...EMANUEL/GUSTAFSON
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 172310
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
410 PM MST SAT JAN 17 2009
.DISCUSSION...
TONIGHT THROUGH MONDAY...THE QUIET WEATHER PATTERN WILL PERSIST
ACROSS THE TFX CWA THROUGH MONDAY. HIGH PRESSURE ALOFT WILL BUILD
INTO THE AREA FROM THE WEST...FOR A CONTINUED DRY BUT DECREASING
NORTHERLY FLOW ALOFT. ONLY LIGHT WESTERLY SURFACE WINDS WILL
PREVAIL THROUGH THE PERIOD. PATCHY FREEZING FOG WILL DEVELOP IN
THE VALLEYS OF FAR SOUTHWEST MONTANA AGAIN TONIGHT AND SUNDAY
NIGHT...AS THE VALLEY INVERSIONS REMAIN IN PLACE THERE. THE CLEAR
SKIES AND RISING HEIGHTS ALOFT WILL BRING WARMING TEMPERATURES TO
THE AREA THROUGH THE PERIOD AS WELL. TEMPERATURES ON SUNDAY WILL
GENERALLY WARM INTO THE MID 40S TO UPPER 50S...WHICH WILL BE NEAR
RECORD HIGH LEVELS FOR MOST AREAS. TEMPERATURES ON MONDAY WILL
WARM FURTHER INTO THE UPPER 40S TO NEAR 60...WHICH AGAIN WILL BE
NEAR OR AT RECORD LEVELS. HOWEVER...A POCKET OF COLD AIR WILL BE
SLOWER TO ERODE ACROSS HILL AND BLAINE COUNTIES...SO WILL GO WITH
SLIGHTLY COOLER TEMPERATURES THERE. WHERE THERE ARE INVERSIONS IN
THE SOUTHWEST VALLEYS...TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW NORMAL AS WELL.
THE WARMING TEMPERATURES WILL ALSO CAUSE INCREASED SNOWMELT AT THE
LOWER AND MID ELEVATIONS THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
THIS WILL CAUSE RIVER AND STREAM LEVELS TO RISE SOMEWHAT.
HOWEVER...TEMPERATURES WILL COOL TO NEAR TO BELOW FREEZING AT
NIGHT...WHICH WILL HINDER SNOWMELT THEN. ALSO...THE WARMING
TEMPERATURES WILL CAUSE AREAS OF ICE BREAKUP...WHICH MAY LEAD TO
LOCALIZED ICE JAMS. ALTHOUGH THERE IS NO SIGN OF RISING RIVER OR
STREAM LEVELS YET...THE POTENTIAL FOR IT WILL CONTINUE INTO EARLY
NEXT WEEK AND THE SITUATION WILL CONTINUE TO BE MONITORED FOR
POSSIBLE HYDROLOGIC STATEMENTS. COULSTON
TUESDAY THROUGH THURSDAY NIGHT...A BROAD UPPER RIDGE REMAINS OVER
THE AREA TO START THE PERIOD BUT 500MB HEIGHTS BEGIN TO FALL WED
NIGHT AS AN UPPER TROF MOVES IN OVER THE WESTERN US AND CANADA
COAST. A WEAK SHORT WAVE WILL TRANSIT THE AREA THURSDAY NIGHT
BRINGING MOISTURE AND THE CHANCE FOR LIGHT SNOW INTO FRIDAY
MORNING. TEMPERATURES WILL COOL THROUGH THE PERIOD. HIGH TEMPS
WILL BE ABOVE SEASONAL AVERAGES TO START THE PERIOD BUT FALL TO
NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES BY THURSDAY.
FRIDAY AND SATURDAY...GENERAL NORTHWEST FLOW OVER MONTANA IS
EXPECTED TO BRING COOLER AIR FROM CANADA BACK TO THE REGION.
TEMPERATURES SHOULD DROP BACK TO SEASONAL AVERAGES FOR MUCH
OF THE AREA. AT THIS POINT A SLIGHT CHANCE FOR SNOW SHOWERS
SATURDAY FOR THE MOUNTAINS ALONG THE DIVIDE AND CENTRAL PLAINS.
GUS
&&
.AVIATION...
UPDATED 2310Z.
EXPECT CLEAR SKIES AT KBZN/KGTF/KHLN/KCTB WITH ONLY SOME CLOUDS
ABOVE 25000 FT MSL FROM TIME TO TIME AT KHVR AND KLWT. FEEL PRETTY
GOOD ABOUT FORECAST WIND SPEEDS AND DIRECTIONS. AM CONFIDENT
IN NEARLY CALM WINDS AT KHLN AND KBZN. EXPECT WIND DIRECTIONS TO
GENERALLY BE WITHIN 30 DEGREES OF THOSE FORECAST AND WIND SPEEDS TO
GENERALLY BE WITHIN A FEW KNOTS OF THOSE FORECAST. BLANK
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 58 34 60 / 0 0 0 0
CTB 33 58 35 61 / 0 0 0 0
HLN 24 49 28 52 / 0 0 0 0
BZN 16 47 19 46 / 0 0 0 0
WEY 3 36 7 41 / 0 0 0 0
DLN 21 45 23 48 / 0 0 0 0
HVR 16 44 23 50 / 0 0 0 0
LWT 26 56 31 58 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...GUSTAFSON/EMANUEL
AVIATION...BLANK
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 172209
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
309 PM MST SAT JAN 17 2009
.DISCUSSION...
TONIGHT THROUGH MONDAY...THE QUIET WEATHER PATTERN WILL PERSIST
ACROSS THE TFX CWA THROUGH MONDAY. HIGH PRESSURE ALOFT WILL BUILD
INTO THE AREA FROM THE WEST...FOR A CONTINUED DRY BUT DECREASING
NORTHERLY FLOW ALOFT. ONLY LIGHT WESTERLY SURFACE WINDS WILL
PREVAIL THROUGH THE PERIOD. PATCHY FREEZING FOG WILL DEVELOP IN
THE VALLEYS OF FAR SOUTHWEST MONTANA AGAIN TONIGHT AND SUNDAY
NIGHT...AS THE VALLEY INVERSIONS REMAIN IN PLACE THERE. THE CLEAR
SKIES AND RISING HEIGHTS ALOFT WILL BRING WARMING TEMPERATURES TO
THE AREA THROUGH THE PERIOD AS WELL. TEMPERATURES ON SUNDAY WILL
GENERALLY WARM INTO THE MID 40S TO UPPER 50S...WHICH WILL BE NEAR
RECORD HIGH LEVELS FOR MOST AREAS. TEMPERATURES ON MONDAY WILL
WARM FURTHER INTO THE UPPER 40S TO NEAR 60...WHICH AGAIN WILL BE
NEAR OR AT RECORD LEVELS. HOWEVER...A POCKET OF COLD AIR WILL BE
SLOWER TO ERODE ACROSS HILL AND BLAINE COUNTIES...SO WILL GO WITH
SLIGHTLY COOLER TEMPERATURES THERE. WHERE THERE ARE INVERSIONS IN
THE SOUTHWEST VALLEYS...TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY
BELOW NORMAL AS WELL.
THE WARMING TEMPERATURES WILL ALSO CAUSE INCREASED SNOWMELT AT THE
LOWER AND MID ELEVATIONS THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
THIS WILL CAUSE RIVER AND STREAM LEVELS TO RISE SOMEWHAT.
HOWEVER...TEMPERATURES WILL COOL TO NEAR TO BELOW FREEZING AT
NIGHT...WHICH WILL HINDER SNOWMELT THEN. ALSO...THE WARMING
TEMPERATURES WILL CAUSE AREAS OF ICE BREAKUP...WHICH MAY LEAD TO
LOCALIZED ICE JAMS. ALTHOUGH THERE IS NO SIGN OF RISING RIVER OR
STREAM LEVELS YET...THE POTENTIAL FOR IT WILL CONTINUE INTO EARLY
NEXT WEEK AND THE SITUATION WILL CONTINUE TO BE MONITORED FOR
POSSIBLE HYDROLOGIC STATEMENTS. COULSTON
TUESDAY THROUGH THURSDAY NIGHT...A BROAD UPPER RIDGE REMAINS OVER
THE AREA TO START THE PERIOD BUT 500MB HEIGHTS BEGIN TO FALL WED
NIGHT AS AN UPPER TROF MOVES IN OVER THE WESTERN US AND CANADA
COAST. A WEAK SHORT WAVE WILL TRANSIT THE AREA THURSDAY NIGHT
BRINGING MOISTURE AND THE CHANCE FOR LIGHT SNOW INTO FRIDAY
MORNING. TEMPERATURES WILL COOL THROUGH THE PERIOD. HIGH TEMPS
WILL BE ABOVE SEASONAL AVERAGES TO START THE PERIOD BUT FALL TO
NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES BY THURSDAY.
FRIDAY AND SATURDAY...GENERAL NORTHWEST FLOW OVER MONTANA IS
EXPECTED TO BRING COOLER AIR FROM CANADA BACK TO THE REGION.
TEMPERATURES SHOULD DROP BACK TO SEASONAL AVERAGES FOR MUCH
OF THE AREA. AT THIS POINT A SLIGHT CHANCE FOR SNOW SHOWERS
SATURDAY FOR THE MOUNTAINS ALONG THE DIVIDE AND CENTRAL PLAINS.
GUS
&&
.AVIATION...
UPDATED 1754Z.
STRONG HIGH PRESSURE ALOFT AND AT THE SURFACE WILL PERSIST AND
THE AIRMASS WILL REMAIN DRY AND STABLE. SURFACE WINDS WILL BE
GENERALLY LIGHT AND OUT OF THE WEST-SOUTHWEST. VFR CONDITIONS
PREVAIL.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 58 34 60 / 0 0 0 0
CTB 33 58 35 61 / 0 0 0 0
HLN 24 49 28 52 / 0 0 0 0
BZN 16 47 19 46 / 0 0 0 0
WEY 3 36 7 41 / 0 0 0 0
DLN 21 45 23 48 / 0 0 0 0
HVR 16 44 23 50 / 0 0 0 0
LWT 26 56 31 58 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON
LONG TERM...GUSTAFSON/EMANUEL
AVIATION...ZELZER
WEATHER.GOV/GREATFALLS
000
FXUS65 KTFX 171755
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1055 AM MST SAT JAN 17 2009
.UPDATE...
ONLY MINOR UPDATES TO ZONE AND STATE FORECASTS THIS MORNING.
TEMPERATURES IN THE VALLEYS OF FAR SOUTHWEST MONTANA NEAR THE
IDAHO BORDER SHOULD NOT WARM UP AS MUCH AS PREVIOUSLY
EXPECTED DUE TO A STRONG INVERSION THERE THAT ALLOWED FOG TO FORM
OVERNIGHT. ALSO...TEMPERATURES ARE GENERALLY RUNNING A BIT COOLER
THAN PREVIOUSLY FORECAST OVER THE PLAINS OF NORTH CENTRAL AND
CENTRAL MONTANA. THEREFORE...WILL LOWER HIGHS A FEW DEGREES ACROSS
ALL OF THESE AREAS. WINDS ARE ALSO BLOWING SLIGHTLY STRONGER THAN
ORIGINALLY EXPECTED ACROSS NORTH CENTRAL AND CENTRAL MONTANA...SO
WILL INCREASE THEM ABOUT 5 TO 10 MPH FOR TODAY. REMAINDER OF
FORECAST IS IN GOOD SHAPE.
NO SIGN OF RISING RIVER LEVELS YET AT AUTOMATED GAUGES...SO WILL
CONTINUE TO MONITOR THAT SITUATION AND HOLD OFF ON ANY STATEMENTS
OR HIGHLIGHTS AT THIS TIME. HAZARDOUS WEATHER OUTLOOK SEEMS TO
HANDLE THE CURRENT SITUATION WELL. COULSTON
&&
.AVIATION...
UPDATED 1754Z.
STRONG HIGH PRESSURE ALOFT AND AT THE SURFACE WILL PERSIST AND
THE AIRMASS WILL REMAIN DRY AND STABLE. SURFACE WINDS WILL BE
GENERALLY LIGHT AND OUT OF THE WEST-SOUTHWEST. VFR CONDITIONS
PREVAIL.
&&
.PREV DISCUSSION...
/ISSUED 430 AM MST SAT JAN 17 2009/
SATURDAY THROUGH MONDAY...QUIET AND MILD CONDITIONS WILL PERSIST
DURING THE PERIOD AS STRONG UPPER-LEVEL RIDGE AND SURFACE HIGH
PRESSURE REMAINS IN PLACE ACROSS THE WESTERN U.S. SOME PATCHY
FREEZING FOG IS POSSIBLE SATURDAY AND SUNDAY MORNINGS OVER THE
HIGH VALLEYS OF SOUTHWEST MONTANA AS SURFACE INVERSIONS...CLEAR
SKIES AND LIGHT WINDS ENABLE TEMPERATURES TO DROP BUT FOG SHOULD
QUICKLY BURN OFF SHORTLY AFTER SUNRISE BOTH DAYS. WINDS WILL
REMAIN LIGHT OUT OF THE WEST-SOUTHWEST ACROSS OUR CWA ALONG WITH
UNSEASONABLY MILD TEMPERATURES THROUGH THE PERIOD RUNNING
APPROXIMATELY 10 TO 20 DEGREES ABOVE AVERAGE. ON SUNDAY...A VERY
WEAK UPPER-LEVEL WAVE MAY BRING A FEW MORE MID TO HIGH CLOUDS
ACROSS THE AREA...OTHERWISE ABUNDANT SUNSHINE CAN BE EXPECTED.
RIDGE AXIS WILL BE OVER OUR AREA ON MONDAY/TUESDAY...THEN WILL
GRADUALLY SHIFT EAST AND SOUTHEAST.
NEAR RECORD HIGH TEMPERATURES ARE POSSIBLE ACROSS SOUTHWEST AND
CENTRAL MONTANA WITH RECORD HIGH TEMPS POSSIBLE OVER THE NORTHERN
ROCKY MOUNTAIN FRONT AND ADJACENT PLAINS ON SUNDAY...WITH NEAR
RECORD HIGH TEMPS POSSIBLE AGAIN ON MONDAY. IN ADDITION...RISING
RIVER LEVELS DUE TO SNOW MELT AND ICE JAMS ARE POSSIBLE AS
TEMPERATURES WARM. AT THIS TIME...RIVER GAUGES ACROSS THE AREA
ARE INDICATING LOW WATER LEVELS WITH MINIMAL FLOODING
THREAT...HOWEVER GIVEN THE DRAMATIC THAW WILL CONTINUE TO CLOSELY
MONITOR THIS SITUATION FOR POSSIBLE HYDROLOGIC HIGHLIGHTS IF ICE
JAMMING AND FLOODING POTENTIAL INCREASES. MLS
MONDAY NIGHT THROUGH THURSDAY NIGHT...MEDIUM RANGE MODELS
CONTINUE TO BE IN HARMONY DURING THE PERIOD. A BROAD UPPER RIDGE
REMAINS OVER THE AREA TO START THE PERIOD BUT 500MB HEIGHTS BEGIN
TO GET KNOCKED DOWN ON WEDNESDAY AS AN UPPER TROF BEGINS TO CARVE
OUT ACROSS CANADA. SHORT WAVE ENERGY ROTATES ACROSS THE AREA ON
THURSDAY BRINGING MOISTURE AND LIFT AND THE CHANCE FOR LIGHT SNOW
THROUGH THURSDAY NIGHT. TEMPERATURES WILL COOL THROUGH THE PERIOD.
AFTERNOON READINGS WILL BE ABOVE SEASONAL AVERAGES TO START THE
PERIOD BUT FALL TO NEAR OR SLIGHTLY BELOW SEASONAL AVERAGES BY
THURSDAY.
FRIDAY AND SATURDAY...A NORTHWEST FLOW OVER MONTANA IS EXPECTED
TO BRING IN A COLDER AIR MASS FROM CANADA. TEMPERATURES MAY FALL
TO BELOW SEASONAL FOR MUCH OF THE CWA. AT THIS POINT A SLIGHT
CHANCE FOR SNOW SHOWERS ON SATURDAY FOR THE MOUNTAINS ALONG THE
DIVIDE AND CENTRAL PLAINS. SAUCIER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 51 32 56 30 / 0 0 0 0
CTB 49 32 56 30 / 0 0 0 0
HLN 46 24 45 25 / 0 0 0 0
BZN 44 17 47 17 / 0 0 0 0
WEY 31 13 39 13 / 0 0 0 0
DLN 42 20 44 20 / 0 0 0 0
HVR 40 19 44 17 / 0 0 0 0
LWT 47 29 53 29 / 0 0 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COULSTON/SYNER
LONG TERM...EMANUEL/SAUCIER
AVIATION...ZELZER
WEATHER.GOV/GREATFALLS
| 
