Area Forecast Discussion
Issued by NWS Great Falls, MT

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000
FXUS65 KTFX 140557
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1050 PM MST SAT FEB 13 2016

AVIATION SECTION UPDATED.

.UPDATE... CURRENT SATELLITE IMAGERY SHOWS INITIAL PUSH OF MOISTURE
FROM NEXT PACIFIC SHORTWAVE TROF HAS MADE IT EAST OF THE DIVIDE AND
IS GENERATING A CHINOOK-ARCH TYPE CLOUD BAND THAT EXTENDS FROM NORTH
OF CUT BANK ALL THE WAY TO YELLOWSTONE NP. CLOUDS WILL CONTINUE TO
INCREASE ACROSS OUR REGION TONIGHT AS ADDITIONAL MOISTURE IN THE ID
PANHANDLE/WESTERN MT MAKES ITS WAY EASTWARD.  PRECIPITATION WILL
GENERALLY BE CONFINED TO THE ROCKY MTN FRONT AND PARTS OF SOUTHWEST
MT THROUGH MIDNIGHT AND THEN SPREAD INTO THE CENTRAL COUNTIES
OVERNIGHT, MAINLY SOUTH AND EAST OF GREAT FALLS.

CURRENT FORECAST IN GOOD SHAPE.  JUST MADE A FEW TWEAKS TO CLOUD
COVER TO BETTER MATCH SATELLITE AND SURFACE OBSERVATIONS.
WARANAUSKAS

&&

.DISCUSSION...

TONIGHT THROUGH MONDAY...A SHORTWAVE HAS MOVED EAST OF THE REGION
AND THE UPPER LEVEL FLOW HAS BECOME NORTHWEST. THIS FLOW HAS
SEVERAL DISTURBANCES MOVING THROUGH IT AND THESE WILL GENERATE
PRECIPITATION OVER MAINLY THE NORTHERN ROCKIES AND SOUTHWEST
MONTANA SUNDAY AND MONDAY. A WINTER WEATHER ADVISORY HAS BEEN
ISSUED FOR THE HIGHER ELEVATIONS OF THE NORTHERN AND SOUTHERN
ROCKY FRONT ZONES, INCLUDING MARIAS PASS BEGINNING LATER TONIGHT.
THE UPPER LEVEL DISTURBANCES WILL ALSO BRING PERIODS OF STRONG,
GUSTY WINDS TO THE REGION. THE FIRST DISTURBANCE WILL STRENGTHEN
WINDS TONIGHT AND EARLY MONDAY. A SECOND, STRONGER DISTURBANCE
WILL STRENGTHEN WINDS AGAIN SUNDAY NIGHT THROUGH MONDAY. THIS
PERIOD MAY REQUIRE HIGHLIGHTS, ESPECIALLY ACROSS THE ROCKIES AND
CENTRAL PORTIONS OF THE CWA, ALTHOUGH AT THIS TIME CONFIDENCE IN
MODEL SOLUTIONS IS NOT HIGH. THIS SECOND DISTURBANCE WILL ALSO
BRING INCREASED CHANCES OF SNOW ACROSS PORTIONS SOUTHWEST MONTANA
INCLUDING WEST YELLOWSTONE. TEMPERATURES THROUGH THIS PERIOD WILL
REMAIN WELL ABOVE SEASONAL NORMALS. ZELZER

MONDAY NIGHT THROUGH SATURDAY...MEDIUM RANGE PERIOD BEGINS ON A
WINDY NOTE AS A LEE SIDE TROF WILL ENHANCE A TIGHT SURFACE GRADIENT
RESULTING IN THE POSSIBILITY OF STRONG WINDS ACROSS THE NORTHERN
PLAINS. 00Z MODEL DATA APPEARS TO BE BACKING OFF A BIT ON THE WIND
SPEEDS FROM EARLIER RUNS BUT ENOUGH CONFIDENCE REMAINS THAT GUSTY
WINDS WILL CONTINUE MONDAY NIGHT THROUGH THE DAY TUESDAY. ISOLATED
SHOWERS ARE ALSO POSSIBLE TUESDAY AS SHORT WAVE ENERGY BRINGS A
PLUME OF PACIFIC MOISTURE THROUGH THE AREA. BY WEDNESDAY, THE UPPER
RIDGE REBUILDS OVER THE AREA WITH ITS AXIS ALONG THE CONTINENTAL
DIVIDE, RESULTING IN DRY AND MILD CONDITIONS. THURSDAY FINDS THE
RIDGE MOVING EAST AS AN UPPER TROF PUSHES INTO THE AREA. THE 12Z
RUNS OF THE GFS AND ECMWF ARE IN BETTER AGREEMENT THAN THEIR 00Z
RUNS REGARDING THE TROF MOVING THROUGH THE STATE. THEY BOTH HAVE
IT OVER CENTRAL MONTANA BY LATE THURSDAY AFTERNOON. AS A RESULT,
SCATTERED SHOWERS THURSDAY WILL LIKELY OCCUR OVER THE WESTERN
MOUNTAINS AND OVER SOUTHWEST MONTANA. A TIGHT SURFACE GRADIENT
THURSDAY WILL ALLOW WINDS TO INCREASE AND BECOME GUSTY AGAIN OVER
THE NORTHERN PLAINS. THE UPPER RIDGE STRONGLY AMPLIFIES OVER THE
AREA FRIDAY BUT IS SHORT- LIVED AS ANOTHER SHORT WAVE APPROACHES
FROM THE WEST FRIDAY NIGHT INTO EARLY SATURDAY. TEMPERATURES WILL
CONTINUE ABOVE SEASONAL AVERAGES.
EMANUEL/COULSTON

&&

.AVIATION...
UPDATED 0550Z.

VFR CONDITIONS ARE EXPECTED ACROSS CENTRAL/SOUTHWEST MT THROUGH
TONIGHT. PACIFIC MOISTURE IS SPREADING MID-LEVEL CEILINGS INTO
WESTERN MT. PRECIPITATION WILL DEVELOP EARLY SUNDAY MORNING OVER THE
ROCKY MOUNTAINS AND INTO SOUTHWEST MT...AFFECTING MAINLY KBZN/KLWT
AS VCSH OR -SHRA. WINDS INCREASE AGAIN SUNDAY MID-MORNING ACROSS THE
NORTH-CENTRAL PLAINS WITH GUSTS OF 25-35 KTS EXPECTED FROM KGTF TO
KCTB. PN

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  34  53  39  54 /  10  10  30  60
CTB  33  50  37  52 /  10  10  20  40
HLN  32  46  36  49 /  20  30  30  40
BZN  26  41  31  44 /  30  40  30  60
WEY  22  33  26  37 /  80  80  80  80
DLN  29  42  35  47 /  20  40  20  30
HVR  30  50  32  50 /  10  10  20  50
LWT  30  45  34  45 /  20  30  40  60

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 11 AM MST
SUNDAY FOR MTZ009-048.

&&

$$

WEATHER.GOV/GREATFALLS


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