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378
FXUS65 KGGW 161532
AFDGGW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
932 AM MDT WED APR 16 2014

.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH FRIDAY...
NORTHWEST FLOW ALOFT THIS MORNING OVER NORTHEAST MONTANA WITH WEAK
SHORT WAVE DISTURBANCES SWEEPING A CROSS SOUTHERN SASKATCHEWAN
AND CENTRAL MONTANA. MOST OF NORTHEAST MONTANA LIES BETWEEN THESE
SHORT WAVES AND THEIR ASSOCIATED MOISTURE. AS A RESULT EXPECT
SCATTERED SHOWERS MAINLY OVER PETROLEUM AND GARFIELD COUNTIES THIS
MORNING AND DECREASING AFTER NOON. ADJUSTED POPS DOWNWARD SLIGHTLY
OVER NORTH CENTRAL PORTION OF CWA THIS MORNING TO REFLECT THIS.
OTHERWISE...CURRENT FORECAST SEEMS TO HANDLE SITUATION WELL SO NO
OTHER UPDATES. BRITTON

.PREVIOUS DISCUSSION...
SHORTWAVES ON NORTHWEST FLOW ALOFT AND A QUASI-STATIONARY FRONT TO
THE WEST WILL BRING CHANCES FOR RAIN AND SNOW SHOWERS TO NORTHEAST
MONTANA TODAY AND TONIGHT ALONG WITH COLDER THAN NORMAL TEMPERATURES.
HOWEVER...A DRY SLOT BETWEEN THE WAVES MAY PROVIDE DRY WEATHER FOR
PART OF THE DAY.

AN UPPER RIDGE MOVES INLAND FROM THE PACIFIC TONIGHT AND INTO
MONTANA ON THURSDAY. THIS WILL BRING THE FRONT BACK EAST AS A WARM
FRONT. A SHORTWAVE IN NW FLOW ALOFT AHEAD OF THE RIDGE WILL BRING
A CHANCE OF RAIN AND SNOW SHOWERS TO THE AREA ON THURSDAY.

THE RIDGE QUICKLY MOVES THROUGH EASTERN MONTANA THURSDAY NIGHT AND
A SHORTWAVE TROUGH AND COLD FRONT FOLLOWS ON FRIDAY WITH A CHANCE
OF RAIN SHOWERS. FORRESTER


.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
SYNOPTIC SET UP...A WEAK RIDGE EXTENDS FROM THE SOUTHERN US HIGH
PLAINS UP THROUGH THE DAKOTAS WHILE A SECOND RIDGE RUNS UP THE
COAST OF CALIFORNIA...THE PACIFIC NORTHWEST...AND BRITISH
COLUMBIA. A WEAK TROUGH LIES BETWEEN THESE TWO FEATURES OVER
MONTANA AND THE HIGH PLAINS OF ALBERTA. FARTHER WEST...A LARGE
TROUGH EXISTS OVER THE BEARING SEA AND IS EJECTING INTO THE GULF
OF ALASKA.

FRIDAY NIGHT...THE TROUGH ALOFT WILL FORM A SURFACE LOW OVER
ALBERTA AND MOVE IT EAST INTO SASKATCHEWAN. A COLD FRONT
EXTENDING DOWN WITH PACIFIC MOISTURE WILL QUICKLY EXIT THE AREA
BUT NOT BEFORE LEAVING RAIN SHOWERS BEHIND THAT EVENING.

SATURDAY THROUGH MONDAY NIGHT...COASTAL RIDGE WILL MOVE INTO THE
AREA AND DRY CONDITIONS OUT WITH WEAK DOWN-SLOPING EFFECT IN THE
SURFACE LAYER THROUGH SATURDAY. THEN THE RIDGE WILL FLATTEN
SLIGHTLY ALLOWING FOR THE WARMER SIDE OF ZONAL FLOW AND SLIGHTLY
UNSTABLE AFTERNOONS. HIGH TEMPERATURES WILL RISE INTO THE 60S AND
70S HELPING TO DESTABILIZE THE SURFACE LAYER A BIT MORE.

TUESDAY ONWARD...SURPRISINGLY...MODELS SEEM TO BE HOLDING TOGETHER
DURING THESE PERIODS WITH FAIRLY WELL MATCHED SYNOPTIC FEATURES
FROM RUN TO RUN AND MODEL TO MODEL. THE MAIN PLAYER IS THE LARGE
TROUGH OVER THE BEARING SEA AND GULF OF ALASKA DROPPING DOWN OVER
THE WESTERN THIRD OF THE CONUS. MODELS HAVE NOT RESOLVED THE
BASE/SOUTHERN COMPONENT OF THIS TROUGH...HOWEVER THEY DO APPEAR TO
BREAK THE TROUGH INTO A NORTHERN AND SOUTHERN COMPONENT WITH THE
NORTHERN COMPONENT BRINGING INCREASED CHANCES FOR PRECIPITATION TO
NORTHEAST MONTANA IN MULTIPLE MODELS. FOR THIS REASON...RAISED
POPS CONSIDERABLY ABOVE THE NORMAL CLIMO OF 15 TO 20 PERCENT
DURING THESE PERIODS. GAH

&&

.AVIATION...
A COLD FRONT AND UPPER LEVEL DISTURBANCE WILL BRING MVFR CEILINGS
TO NORTHEAST MONTANA TODAY. THIS SHORT-WAVE TROUGH/DISTURBANCE
COULD GENERATE PERIODS OF LIGHT SNOW OR RAIN TODAY AND THIS
EVENING. THE INTERMITTENT PRECIPITATION COULD LIMIT VISIBILITIES
AT TIMES TO MVFR/IFR. EXPECT NORTHEAST WIND AT 10-15KT.

THURSDAY...A WARM FRONT PUSHING COULD BRING IN ANOTHER ROUND OF
INTERMITTENT SNOW IN THE MORNING...CHANGING TO OCCASIONAL RAIN
SHOWERS IN THE AFTERNOON. AGAIN EXPECT MVFR CEILINGS...AND MVFR
VISIBILITIES AT TIMES. WIND WILL BE MORE SOUTHEASTERLY AT 10-15KT.
SCT

&&

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

&&

$$

WEATHER.GOV/GLASGOW






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