Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 141748
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1048 AM MST SUN FEB 14 2016

AVIATION SECTION UPDATED

.DISCUSSION...

THE REGION IS CURRENTLY BETWEEN UPPER LEVEL DISTURBANCES,THE
AIRMASS HAS DRIED, AND MOST PRECIPITATION IS LIMITED TO THE
ROCKIES. THE WINTER WEATHER ADVISORY FOR THE ROCKIES HAS BEEN
CANCELLED. UPDATED FIRST PERIOD POPS, WX, AND QPF. ZELZER

&&

.AVIATION...UPDATED 1747Z.

STRONG NORTHWEST WINDS ALOFT WILL STRENGTHEN AROUND MIDNIGHT AS A
DISTURBANCE MOVES THROUGH THE FLOW. THESE WINDS WILL REMAIN STRONG
THROUGH MONDAY. GUSTY SURFACE WINDS WILL DIMINISH SOMEWHAT THIS
EVENING BUT BECOME VERY STRONG AND GUSTY MONDAY. MID-LEVEL CLOUDS
WILL INCREASE FROM THE WEST DURING THE NIGHT AS THE UPPER LEVEL
DISTURBANCE APPROACHES. LOCAL MVFR CONDITIONS ARE POSSIBLE AS
PRECIPITATION DEVELOPS OVER THE ROCKIES AND SPREADS EAST. MOUNTAIN
OBSCURATION IS ALSO POSSIBLE AFTER MIDNIGHT.

&&

.PREV DISCUSSION...
/ISSUED 455 AM MST SUN FEB 14 2016/

TODAY THROUGH TUESDAY...MILD AND WINDY CONDITIONS CONTINUE OVER
THE REGION WITH A STRONG WEST-NORTHWEST FLOW ALOFT. PACIFIC
MOISTURE EMBEDDED IN THE FLOW WILL PRODUCE PERIODS OF RAIN AND
MOUNTAIN SNOW. WINDS ARE LIKELY TO CYCLE UP AND DOWN THROUGH THE
PERIOD, WITH PEAKS OCCURRING THIS AFTERNOON, MONDAY MORNING, AND
TUESDAY MORNING. WIND GUSTS MAY REACH UP TO 45 MPH ACROSS NORTH-
CENTRAL MONTANA WITH EACH PASSING WAVE...EXCEEDING 60 MPH ALONG
THE ROCKY MOUNTAIN FRONT. THESE WINDS CAN CAUSE DIFFICULT DRIVING
IN CROSS WINDS. HOWEVER...AT THIS TIME THERE DOES NOT APPEAR TO
BE AN ADEQUATE MECHANISM IN PLACE TO MIX STRONGER WINDS ABOVE THE
FRICTION LAYER DOWN TO THE SURFACE. THUS, WILL TO HOLD OFF ON
ISSUING HIGH WIND HIGHLIGHTS AND ADVISE SUBSEQUENT SHIFTS TO
MONITOR CLOSELY. PRECIPITATION SPREADS THROUGH CENTRAL AND
SOUTHWEST MONTANA LATE SUNDAY NIGHT THROUGH MONDAY NIGHT. SNOW
LEVELS DURING THIS PERIOD WILL REMAIN GENERALLY AROUND 5-6 KFT.
SNOW ACCUMULATIONS OF 5-10 INCHES MAY BE POSSIBLE OVER THE
NORTHERN ROCKIES, KINGS HILL PASS AND INTO THE MADISON RANGE OF
SOUTHERN MADISON AND GALLATIN COUNTY. PN

TUESDAY NIGHT THROUGH SUNDAY...THE PERIOD BEGINS WITH A FLAT UPPER
RIDGE OVER THE AREA. WEAK SHORT WAVE ENERGY, ALONG WITH A PLUME OF
PACIFIC MOISTURE MOVING THROUGH THE RIDGE POSITION, WILL RESULT IN
SCATTERED SNOW OVER THE WESTERN MOUNTAINS AND ISOLATED SNOW OVER THE
BELTS AND SNOWIES. THE RIDGE AMPLIFIES A BIT ON WEDNESDAY IN
RESPONSE TO AN UPPER TROF APPROACHING THE WEST COAST. MODELS IN
FAIRLY DECENT AGREEMENT BRINGING THE UPPER TROF TO WESTERN MONTANA
THURSDAY. A RATHER DEEP SURFACE LOW OVER SOUTHEAST ALBERTA WILL
TIGHTEN THE PRESSURE GRADIENT ALLOWING FOR INCREASING WINDS
THURSDAY AFTERNOON AND LIMITING ANY PRECIPITATION TO JUST ISOLATED
SHOWERS OVER THE PLAINS. THE UPPER RIDGE REBUILDS OVER THE AREA
FRIDAY FOR DRY CONDITIONS. FALLING SURFACE PRESSURE ACROSS CANADA ON
FRIDAY SETS UP A LEE SIDE TROF THAT WILL ALLOW WINDS TO REMAIN GUSTY
INTO THE EVENING. THE PRESSURE GRADIENT RELAXES A BIT SATURDAY BUT
SHORT WAVE ENERGY THAT ONCE AGAIN FLATTENS THE RIDGE WILL BRING
ISOLATED SHOWERS TO THE PLAINS. BY SUNDAY, THE RIDGE REBUILDS
STRONGLY OVER THE WESTERN U.S. AND A DRY NORTHWEST FLOW ALOFT SETS UP
OVER THE AREA. TEMPERATURES WILL REMAIN ABOVE SEASONAL AVERAGES WITH
HIGHS GENERALLY IN THE 50S, THE EXCEPTION BEING THE SOUTHWEST
VALLEYS WHERE IT WILL REMAIN N THE 40S.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  52  38  55  38 /  20  20  70  30
CTB  50  37  52  32 /  10  20  50  30
HLN  46  36  49  35 /  10  30  50  40
BZN  41  30  44  30 /  10  30  50  50
WEY  33  26  36  28 /  30  50  80  40
DLN  42  35  47  34 /  10  20  30  20
HVR  51  32  48  28 /  10  20  60  20
LWT  44  33  44  30 /  30  20  80  30

&&

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

$$

WEATHER.GOV/GREATFALLS


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