Weather Service Report


180 
FXUS65 KTFX 250327
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
927 PM MDT FRI APR 24 2015

.UPDATE...
RAIN IS GRADUALLY CHANGE TO SNOW OVER PORTIONS OF SOUTHWEST
MT...INCLUDING THE VALLEY LOCATIONS. SNOW ACCUMULATIONS OF AN INCH
OR TWO ARE POSSIBLE ON GRASSY AREAS IN THE VALLEYS OF THE
SOUTHWEST...WITH 3 TO 5 INCHES IN THE MOUNTAINS. MOUNTAIN PASS
ROADWAYS HAVE BEEN MELTING MOST OF THE SNOW THIS EVENING...BUT ARE
LIKELY TO BECOME SNOW COVERED AFTER MIDNIGHT. FOR NOW I WILL HOLD
OFF ON AN ADVISORY...BUT CONTINUE TO MONITOR PASS CONDITIONS
OVERNIGHT. OTHERWISE...LIGHT RAIN IS MAINLY AFFECTING AREAS EAST
OF HIGHWAY 87 FROM GREAT FALLS TO HAVRE...WITH JUST A FEW ISOLATED
SHOWERS WEST OF I-15. OVERNIGHT LOWS LOOK ON TRACK. THE REST OF
THE FORECAST IS ON TRACK. BRUSDA

&&

.AVIATION... 
UPDATED 2350Z. 

AN UPPER LEVEL DISTURBANCE WILL CONTINUE TO MOVE NORTHEASTWARD THRU 
THE REGION. EXPECT WIDESPREAD RAIN/SNOW TO AFFECT SOUTHWEST AND 
CENTRAL MT THRU 14Z SATURDAY. MOUNTAINS WILL BE OBSCURED. PRECIP 
BECOMES MORE SCATTERED DURING THE DAY ON SATURDAY. EXPECT IFR/LIFR 
CONDITIONS IN/NEAR AREAS OF PRECIPITATION. A WIND SHIFT TO THE NORTH 
WILL MOVE SOUTHWARD THRU NORTH CENTRAL MT DURING THE AFTERNOON 
HOURS. BRUSDA

&&

.PREV DISCUSSION...
/ISSUED 550 PM MDT FRI APR 24 2015/

TONIGHT THROUGH SUNDAY...UPPER LEVEL TROUGH/LOW CURRENTLY CENTERED OVER
SW BC WILL SLOWLY DRIFT INLAND THROUGH THE WEEKEND WHILE SEVERAL SHORTWAVES
MOVE THROUGH WESTERLY FLOW TO THE S OF THE LOW AND LIFT NE ACROSS
MT. FIRST SHORTWAVE CURRENTLY MOVING INTO EASTERN WA/OR WILL MOVE
INTO WESTERN MT THIS EVENING THEN TRACK NE ACROSS CENTRAL MT INTO
SK LATE TONIGHT THROUGH EARLY SATURDAY MORNING. LIGHT SHOWERS
ALREADY OCCURRING ACROSS MUCH OF SW AND CENTRAL MT THIS AFTERNOON
WILL INCREASE AND TRACK NE TONIGHT AS THE SHORTWAVE APPROACHES AND
THE FRONTOGENIC ZONE FROM SW TO NE ACROSS THE AREA INTENSIFIES.
MODELS REMAIN IN GOOD AGREEMENT FOCUSING A SWATH OF 0.25" TO
0.50" OF PRECIPITATION FROM THE SW AND CENTRAL MT MTNS NORTH
THROUGH THE BEARS PAW AND VICINITY WITH LOCAL AMOUNTS IN EXCESS OF
0.50" LIKELY ACROSS PARTS OF JUDITH BASIN, EASTERN CHOUTEAU,
SOUTHERN HILL, BLAINE AND FERGUS COUNTIES. A BRIEF PERIOD OF
DRYING MOVES ACROSS THE REGION BEHIND THE EXITING SHORTWAVE ON
SATURDAY WITH ADDITIONAL BUT LESS ORGANIZED ENERGY SHIFTING INTO
ID AND SW MT LATE SATURDAY AFTERNOON THROUGH SUNDAY. HOENISCH

SUNDAY NIGHT THROUGH FRIDAY...THE PERIOD BEGINS WITH AN UPPER
TROF...AND ASSOCIATED SHOWERS... EXITING THE AREA TO THE EAST
WHILE A POSITIVE TILT UPPER RIDGE BUILDS INTO WESTERN MONTANA.
DRY AND STABLE CONDITIONS WILL RULE MONDAY AND TUESDAY AS THE
UPPER RIDGE AXIS SHIFTS EAST OF THE CONTINENTAL DIVIDE. MODELS
BEGIN TO DISAGREE WITH THEIR SOLUTIONS WEDNESDAY. BOTH THE GFS
AND CANADIAN MODELS MAINTAIN THE UPPER RIDGE OVER THE AREA WHILE
THE ECMWF MOVES A WEAK SHORTWAVE ACROSS CENTRAL MONTANA. HAVE
GONE WITH THE DRIER SOLUTION. BY THURSDAY...ALL THREE MODELS
BRING SOME MOISTURE THROUGH THE RIDGE AND DEVELOP SCATTERED
SHOWERS OVER PORTIONS OF SOUTHWEST MONTANA. FRIDAY WILL FIND THE
RIDGE AXIS PUSHED TO EASTERN MONTANA WHILE UNSTABLE AND MOIST
SOUTHWEST FLOW ALOFT STRENGTHENS IN ADVANCE OF AN UPPER TROF THAT
MOVES ONSHORE OF THE WEST COAST. THIS WILL RESULT IN SCATTERED
SHOWERS DEVELOPING FRIDAY AFTERNOON. TEMPERATURES WILL REMAIN
ABOVE SEASONAL AVERAGES WITH AFTERNOON READINGS GENERALLY IN THE
70S FROM TUESDAY THROUGH THE REMAINDER OF THE WEEK. 

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  36  56  34  52 / 100  10  30  40 
CTB  33  54  29  53 /  10  10  20  30 
HLN  35  57  36  54 /  60  20  50  70 
BZN  34  54  35  52 / 100  30  50  60 
WEY  30  51  27  50 /  70  40  40  60 
DLN  34  52  35  51 / 100  30  60  60 
HVR  40  61  32  57 / 100  30  10  20 
LWT  36  54  35  51 / 100  30  20  50 

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

WEATHER.GOV/GREATFALLS

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