Area Forecast Discussion
Issued by NWS Glasgow, MT

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000
FXUS65 KGGW 270403 AAB
AFDGGW

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GLASGOW MT
1003 PM MDT THU MAR 26 2015

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

THE STATIONARY FRONTAL BOUNDARY IS DRAPED NW TO SE ACROSS
NORTHEAST MONTANA THIS EVENING. THE UPPER RIDGE AXIS IS CENTERED
OVER THE INTER-MOUNTAIN WEST. THEREFORE FLOW ALOFT IS
NORTHWESTERLY. MOISTURE RIDING OVER THE TOP OF THE RIDGE IS
INTERACTING WITH THE BOUNDARY AND A SURFACE TROUGH FOR LIGHT
SHOWERS AND MID-LEVEL CLOUDS LOCALLY. BOTH THE TROUGH AND THE
BOUNDARY WILL SHIFT EAST TONIGHT TO BRING IN WARMER AIR...WHICH IS
VERY EVIDENT ON THE 00Z KGGW SOUNDING. WITH TEMPERATURES STILL IN
THE 40S AND UPPER 30S...EXPECT LOWS TONIGHT AROUND 10 DEGREES
ABOVE LAST NIGHT. CONDITIONS ARE GENERALLY MATCHING THE FORECAST.
THEREFORE FEW CHANGES WERE MADE...MAINLY TO WIND GRIDS. ALSO
TRIMMED BACK POPS AND QPF SINCE RADAR ECHOES ARE WEAK. SCT

PREVIOUS DISCUSSION...
SYNOPTIC SET UP...A LARGE COLD TROUGH SETS OVER THE MISSISSIPPI
VALLEY AND GREAT LAKES...WHILE A LARGE WARM RIDGE RESIDES OVER
THE WESTERN THIRD OF THE CONUS AND CANADA. NORTHEAST MONTANA LIES
IN BETWEEN THESE TWO FEATURES UNDER THE WARMER SIDE OF NORTHWEST
FLOW ALOFT.

TONIGHT...MOISTURE HANGING IN TOUGH THIS AFTERNOON MAY CONTINUE
TO PLAGUE THE MISSOURI RIVER VALLEY FROM THE DAM TO THE ND BORDER
AND AREAS NORTH OF IT AS EXTRA SNOW ON THE GROUND FROM EARLIER
MELTS THIS AFTERNOON.

FRIDAY TO FRIDAY NIGHT...850 MB TEMPERATURES WILL ENTER INTO THE
DOUBLE DIGITS CELSIUS. THIS WILL TRANSLATE DOWN INTO VERY WARM
TEMPERATURES IN THE 60S AND 70S FOR HIGHS AND OVERNIGHT LOWS ABOVE
FREEZING FOR MOST LOCATIONS. AREAS WHERE SNOW COVER PERSISTS INTO
FRIDAY MORNING MAY NOT QUITE TOP OUT AS EXPECTED THOUGH.

SATURDAY...INITIALLY A WARM DAY. BUT WHEN THE RIDGE EXITS TO THE
EAST...THIS WILL RAPIDLY CHANGE. A WEAK SHORTWAVE HOT ON THE
RIDGE HEALS WILL SPIRAL UP A SURFACE LOW OVER SOUTHERN CANADA AND
700 MB LOW OVER NORTHEAST MONTANA. A COLD FRONT WILL FORM...
STRENGTHEN...AND THEN MOVE THROUGH THE AREA BY THE AFTERNOON
HOURS. WINDS BEHIND THE FRONT WILL QUICKLY BECOME VERY STRONG DUE
TO THE TIGHT PGF AND EXTRA CAA BEHIND IT. POST FRONTAL RAIN
SHOWERS ARE ALSO ANTICIPATED WITH THIS FRONT BUT TOTALS ARE ANEMIC
WITH LESS THAN A TENTH OF AND INCH FOR MOST AREAS WITH THE QUICK
PASSAGE. GAH


.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
NOT TOO MANY CHANGES WERE MADE BUT HONED IN ON WINDS SATURDAY
NIGHT...GETTING MORE DETAILED. DIDN/T MAKE ANY CHANGES TO THINGS
WITH TUESDAY SYSTEM. BLENDED TEMPS/WINDS AND SKY A BIT TO NEW
MODEL GUIDANCE. TFJ

PREVIOUS DISCUSSION... SHORTWAVE TROF PUSHING THROUGH THE REGION
THIS WEEKEND WITH SOME LINGERING SHOWERS AND WINDY CONDITIONS ON
SATURDAY NIGHT. UPPER RIDGE THEN REBOUNDS FOR WARM AND DRY
CONDITIONS RETURNING FOR EARLY NEXT WEEK. SOME MODEL DIFFERENCES
WITH NEXT SHORTWAVE TO PUSH INTO THE RIDGE BUT THIS WAVE IS
EXPECTED TO SHIFT THE LONGWAVE PATTERN TO A MORE ZONAL/SLIGHTLY
CYCLONIC FLOW ACROSS THE WESTERN STATES THROUGH THE MIDWEEK
PERIOD. RESULT WILL BE COOLER AND MORE UNSETTLED WEATHER FOR
TUESDAY THROUGH THURSDAY WITH INTERMITTENT MIXED PRECIPITATION
CHANCES. EBERT

&&

.AVIATION...
A NW TO SE STATIONARY FRONT OVER THE AREA WILL KEEP MID- LEVEL
CLOUDS IN THE AREA TONIGHT. CIGS WILL BE VFR.

AREA WINDS: SOUTHEAST AT 10 KTS OR LESS THROUGH TONIGHT...THEN
SWITCHING TO THE WEST FRIDAY MORNING.

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW





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