Area Forecast Discussion
Issued by NWS Great Falls, MT

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000
FXUS65 KTFX 062127
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
327 PM MDT WED MAY 6 2015

.DISCUSSION...

TONIGHT THROUGH FRIDAY...THE UPPER LEVEL LOW PRESSURE AREA OVER
THE PACIFIC NORTHWEST WILL SEPARATE FROM THE MAIN UPPER TROUGH
OVER WESTERN CANADA THROUGH THE PERIOD AND MOVE INTO THE
SOUTHWESTERN UNITED STATES. AS A RESULT, MOISTURE FROM OFF THE
CALIFORNIA COAST AND THE GULF OF MEXICO WILL BE DRAWN INTO
SOUTHWEST MONTANA BY AN INCREASINGLY DIFFLUENT SOUTHERLY FLOW
ALOFT THROUGH MOST OF THE DAY ON THURSDAY. THIS WILL FOCUS
NUMEROUS RAIN/SNOW SHOWERS WITH ISOLATED AFTERNOON/EVENING
THUNDERSTORMS OVER SOUTHWEST MONTANA. TEMPERATURES THERE WILL
LIKELY REMAIN ABOVE FREEZING IN THE VALLEYS, SO SNOW ACCUMULATION
IS NOT EXPECTED THERE. HOWEVER, LIGHT MEASURABLE SNOW IS LIKELY
ABOVE MOUNTAIN PASS LEVEL. NORTH CENTRAL MONTANA WILL REMAIN DRY
WITH PARTLY TO MOSTLY CLOUDY SKIES THROUGH THIS PERIOD. THE UPPER
LOW WILL THEN LINGER OVER THE SOUTHWESTERN CONUS INTO FRIDAY, WITH
ITS MAIN INFLUENCE BEING A CONTINUED, THOUGH NOT AS SUBSTANTIAL,
FEED OF GULF MOISTURE. THE MAIN TROUGH WILL MOVE EAST ACROSS
CANADA DURING THIS TIME, SPREADING THE CHANCE FOR SHOWERS FROM
SOUTHWEST MONTANA INTO CENTRAL MONTANA. THE MORE NORTHERLY FLOW
ALOFT IN THE WAKE OF THE TROUGH WILL ALSO BRING A SLIGHT CHANCE OF
SHOWERS TO THE ROCKY MOUNTAIN FRONT AND HI-LINE AREAS.
TEMPERATURES WILL CONTINUE TO BE COOL THROUGH THE PERIOD, AS HIGHS
WILL MOSTLY BE AROUND 10 DEGREES BELOW NORMAL, WHILE OVERNIGHT
LOWS REMAIN IN THE MID 20S AND 30S.  COULSTON

FRIDAY NIGHT THRU WEDNESDAY...EXPECT SCATTERED SHOWERS TO
CONTINUE TO AFFECT MUCH OF SOUTHWEST MT THRU THE PERIOD...AS A
SLOW MOVING UPPER LEVEL LOW MOVES THRU THE CENTRAL ROCKIES.
PRECIPITATION AMOUNTS WILL GENERALLY BE LIGHT THRU THE PERIOD.
ADDITIONALLY...THE AIRMASS WILL BE COLD ENOUGH THAT SNOW WILL
OCCUR IN THE MOUNTAINS. MOST OF THE ACCUMULATING SNOW WILL OCCUR
ABOVE 6500 FEET FRIDAY NIGHT AND SATURDAY. SNOW ACCUMULATIONS OF 1
TO 2 INCHES WILL BE POSSIBLE IN THE KINGS HILL AND BIG SKY AREAS
DURING THIS TIME. OTHERWISE...LITTLE TO NO PRECIPITATION IS
EXPECTED OVER MUCH OF NORTH CENTRAL MT UNTIL NEXT WEDNESDAY. AT
THAT TIME...THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM IS EXPECTED
TO MOVE INLAND FROM THE PACIFIC NORTHWEST. THUS POPS HAVE BEEN
INCREASED A BIT CLOSER TO CLIMO FOR THIS PERIOD. IN TERMS OF
TEMPERATURES...IT WILL REMAIN COOL THRU THE WEEKEND...THEN A SLOW
WARMING TREND IS EXPECTED FOR MONDAY THROUGH WEDNESDAY. BRUSDA

&&

.AVIATION...
UPDATED 1750Z.

ISOLATED TO SCATTERED SHOWERS WILL CONTINUE TO AFFECT MUCH OF
SOUTHWEST MONTANA THROUGH THURSDAY MORNING. EXPECT MVFR/VFR
CEILINGS AND MOUNTAIN OBSCURATIONS ACROSS SOUTHWEST MONTANA
THROUGH THE FORECAST PERIOD. SCATTERED TO BROKEN MID LEVEL CLOUDS
WILL LINGER ACROSS NORTH CENTRAL MONTANA WITH WIDESPREAD VFR
CONDITIONS PREVAILING THROUGH THE PERIOD. HOWEVER, AREAS OF MVFR
CEILINGS REMAIN POSSIBLE, ESPECIALLY AFTER 00Z THURSDAY. MPJ

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  34  52  34  53 /  10  10  10  20
CTB  29  53  28  54 /  10  10  10  20
HLN  39  54  35  56 /  30  40  20  30
BZN  37  51  32  52 /  40  60  20  40
WEY  31  51  28  52 /  60  70  30  60
DLN  37  49  33  53 /  70  70  20  30
HVR  30  56  31  57 /   0   0   0  20
LWT  32  50  34  51 /  10  10  10  40

&&

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

$$

WEATHER.GOV/GREATFALLS


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