FXUS65 KTFX 050540
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1040 PM MST SAT FEB 4 2012
.DISCUSSION...
GENERALLY QUIET NIGHT AND GOING FORECAST ON TRACK. MADE SOME
MODEST ADJUSTMENTS TO LOWER TEMPERATURES IN SOME OF THE COLDER
SOUTHWEST VALLEYS...TEMPERATURES WERE QUICKLY APPROACHING THOSE
FORECASTED OVERNIGHT LOWS...AND TEMPERATURES LAST NIGHT QUITE A
BIT COLDER IN A COUPLE OF LOCATIONS. WITH GENERALLY CLEAR SKIES
AND AN ONLY SLIGHTLY WARMER AIR MASS...FEEL TEMPERATURES WILL DROP
SEVERAL DEGREES MORE BEFORE MORNING. PATCHY FREEZING FOG IS STILL
POSSIBLE LATER TONIGHT IN SOME OF THE COLDER SOUTHWEST VALLEYS.
&&
.AVIATION...
UPDATED 0540Z.
HIGH PRESSURE ALOFT CONTINUES TO PROVIDE DRY AND STABLE CONDITIONS.
SURFACE WINDS WILL BE LIGHT. VFR CONDITIONS PREVAIL WITH ISOLATED
MVFR CONDITIONS OVER THE HIGH VALLEYS OF SOUTHWEST MONTANA DUE TO
FOG.
&&
.PREV DISCUSSION...
/ISSUED 545 PM MST SAT FEB 4 2012/
TONIGHT THROUGH MONDAY...FAIRLY QUIET WEATHER IS EXPECTED OVER
MONTANA TONIGHT THROUGH SUNDAY EVENING. AN UPPER LEVEL HIGH
PRESSURE SYSTEM WILL REMAIN OVER THE STATE THROUGH THIS PERIOD FOR
MOSTLY CLEAR SKIES AND GENERALLY LIGHT WINDS. THE HIGH PRESSURE
ALOFT WILL ALLOW FOR AREAS OF DENSE FOG IN THE HIGHER SOUTHWEST
VALLEYS EACH NIGHT AND MORNING BUT THE REMAINDER OF THE FORECAST
AREA SHOULD CONTINUE TO SEE FAIRLY PLEASANT WEATHER WITH
TEMPERATURES CLIMBING WELL ABOVE SEASONAL AVERAGES FOR SUNDAY
AFTERNOON HIGHS. THE SITUATION CHANGES LATE SUNDAY NIGHT AND
THROUGH THE DAY ON MONDAY. DURING THIS TIME FRAME AN UPPER LEVEL
SHORTWAVE WILL SWING SOUTH THROUGH ALBERTA AND SASKATCHEWAN
BRINGING A SURFACE COLD FRONT INTO NORTH CENTRAL MONTANA. WINDS
SHIFT TO THE NORTH AND NORTHEAST BEHIND THE FRONT FOR UPSLOPE FLOW
ON NORTHERN AND EASTERN SLOPES OF THE VARIOUS MOUNTAIN RANGES
ACROSS THE NORTHERN HALF OF MY CWA. MOISTURE CURRENTLY LOOKS
FAIRLY LIMITED BUT BELIEVE THERE WILL BE ENOUGH TO SQUEEZE OUT
SCATTERED SNOW SHOWERS IN THIS AREA. AT THIS TIME IT APPEARS THAT
ANY SNOW ACCUMULATIONS WILL LIKELY REMAIN LESS THAN AN INCH.
HIGH TEMPERATURES ON MONDAY WILL ALSO DROP TO NEAR OR BELOW
SEASONAL AVERAGES. MPJ
MONDAY NIGHT THROUGH SATURDAY...A WEAK SHORTWAVE WILL MOVE SOUTH
FROM CANADA AND CROSS THE BORDER EARLY MONDAY EVENING. A COLD FRONT
ASSOCIATED WITH THIS FEATURE WILL BRING COOLER AIR ACROSS THE REGION
BY MONDAY EVENING. MOISTURE WILL BE AVAILABLE AT LOWER LEVELS
ALTHOUGH THE STRENGTH OF THE COLD FRONT AND UPSLOPE FLOW WILL BE
WEAK. THUS...POPS MAY INDICATE WIDESPREAD PRECIP ALTHOUGH PRECIP
AMOUNTS MONDAY NIGHT WILL BE ON THE LOW SIDE. THE AIR MASS WILL BE
DRY BY WEDNESDAY ALTHOUGH ANOTHER SHORTWAVE WILL MOVE THROUGH THE
NORTHWEST FLOW ALOFT. THIS WILL TIGHTEN THE SURFACE PRESSURE
GRADIENT SOMEWHAT AND BREEZY CONDITIONS WILL DEVELOP ACROSS THE
ROCKIES AND ADJACENT PLAINS. UNSETTLED NORTHWEST FLOW ALOFT WILL
CONTINUE THROUGH FRIDAY NIGHT AND KEEP A CHANCE OF SHOWERS IN THE
FORECAST...MAINLY OVER THE WESTERN AND SOUTHWESTERN MOUNTAINS. THE
MODELS SHOW A BIT OF A DIFFERENCE THURSDAY WHEN THE ECMWF BRINGS A
SHARPER SHORTWAVE ACROSS THE CANADIAN BORDER THAN THE GFS...AND THE
ASSOCIATED COLD FRONT IS STRONGER AS WELL. THIS LOOKS REASONABLE AND
WILL KEEP TEMPS CLOSER TO NORMALS. A HIGH PRESSURE RIDGE WILL BE
OVER THE ZONES SATURDAY AND KEEP TEMPS WELL ABOVE NORMALS. ZELZER
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 26 49 24 31 / 0 0 0 30
CTB 20 46 19 28 / 0 0 10 30
HLN 14 41 17 34 / 0 0 0 20
BZN 8 44 16 40 / 0 0 0 10
WEY -14 30 3 29 / 0 0 0 0
DLN 12 44 18 39 / 0 0 0 0
HVR 15 47 19 34 / 0 0 10 20
LWT 19 49 20 30 / 0 0 0 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...LOSS
LONG TERM...ZELZER
AVIATION...EMANUEL
WEATHER.GOV/GREATFALLS
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