Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 121155
AFDTFX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
455 AM MST FRI FEB 12 2016

UPDATED AVIATION SECTION

.DISCUSSION...

TODAY THROUGH SUNDAY...HEIGHTS ARE SLOWLY RISING THIS MORNING AS
THE WESTERN U.S. RIDGE AXIS DRIFTS CLOSER TO WESTERN MT. WEAK
ASCENT ASSOCIATED WITH LOW- TO MID- LEVEL WARM ADVECTION IS
SPREADING LIGHT RAIN AND MOUNTAIN SNOW SHOWERS ACROSS CENTRAL AND
SOUTHWEST AREAS OF THE STATE. SURFACE TEMPERATURES ACROSS THE
NORTH CENTRAL PLAINS REMAIN NEAR TO JUST BELOW FREEZING. MOISTURE
OVERRUNNING THIS COLD AIR DOES CREATE THE POSSIBILITY FOR TRACE
AMOUNTS OF LIGHT FREEZING RAIN AT A FEW LOCATIONS MAINLY ALONG THE
MILK RIVER VALLEY FROM AROUND HAVRE TO CHINOOK. PRECIPITATION WILL
CLEAR THE AREA FROM SOUTHWEST TO NORTHEAST THROUGH THE AFTERNOON
WHILE SNOW LEVELS RISE TO NEAR 7000 FT MSL. THE NEXT SHORTWAVE
CROSSES THE PACIFIC NW AND MOVES INTO WESTERN MT EARLY SATURDAY.
RAIN AND SNOW SHOWERS ONCE AGAIN SPREAD THROUGH CENTRAL AND
SOUTHWEST MT WITH THE PASSING PACIFIC FRONT. SNOWFALL AMOUNTS OF
AROUND ONE-HALF TO AN INCH OR TWO WILL BE POSSIBLE IN THE
MOUNTAINS AS SNOW LEVELS DROP BACK DOWN TO AROUND 4000 FT MSL
SATURDAY EVENING. STRONG SUBSIDENCE ALOFT AND SURFACE PRESSURE
RISES ASSOCIATED WITH THE FRONTAL PASSAGE WILL GENERATE WIND GUSTS
OF AROUND 30 TO 40 MPH ON THE NORTH- CENTRAL PLAINS SATURDAY
AFTERNOON AND EVENING. RISING HEIGHTS WITH WEAK WARM ADVECTION
RETURNS ON SUNDAY TO PRODUCE ANOTHER ROUND OF LIGHT SHOWERS ACROSS
CENTRAL AND SOUTHWEST MONTANA. PN

SUNDAY NIGHT THROUGH FRIDAY...A SOMEWHAT ACTIVE WEATHER PATTERN IS
IN STORE FOR THE MEDIUM RANGE PERIOD. WITH AN UPPER RIDGE ALONG THE
WEST COAST, THE PERIOD BEGINS WITH RATHER UNSETTLED NORTHWEST FLOW
ALOFT OVER THE AREA. SHORT WAVE ENERGY MOVING WITHIN THIS FLOW ALOFT
WILL BRING SCATTERED MOUNTAIN SNOW AND ISOLATED RAIN SHOWERS TO THE
PLAINS MONDAY AND TUESDAY. PRECIPITATION AMOUNTS OVER THE PLAINS
WILL BE LIGHT AS A LEE SIDE TROF THAT DEVELOPS MONDAY WILL RESULT IN
INCREASING DOWNSLOPE WINDS. HIGH WINDS MAY DEVELOP ALONG THE ROCKY
MOUNTAIN FRONT AND ADJACENT PLAINS BUT MODEL DIFFERENCES DEPICTING
THE LEE SIDE TROF RESULT IN LOW CONFIDENCE AT THIS TIME REGARDING
ANY POSSIBLE HIGHLIGHTS THAT MAY BE NEEDED. ISOLATED SHOWERS
DECREASE ON WEDNESDAY AS A SOMEWHAT FLATTENED RIDGE MOVES TO THE
CONTINENTAL DIVIDE. MODELS DIVERGE WITH THEIR SOLUTIONS THURSDAY
WITH THE GFS BRINGING AN UPPER TROF ACROSS THE AREA RESULTING IN
RAIN AND/OR SNOW SHOWERS OVER THE WESTERN MOUNTAINS AND SOUTHWEST
MONTANA. MODEL DIFFERENCES CONTINUE FRIDAY WITH THE GFS REBUILDING
THE UPPER RIDGE WHILE THE ECMWF SPINS SHORT WAVE ENERGY OUT OF AN
UPPER TROF APPROACHING WESTERN MONTANA. HAVE LEANED TOWARD A WETTER
EUROPEAN SOLUTION. TEMPERATURES WILL CONTINUE ABOVE SEASONAL
AVERAGES THROUGH THE PERIOD.

&&

.AVIATION...
UPDATED 1155Z.
AREAS OF LIGHT RAIN AND/OR LIGHT SNOW CONTINUE TO SPREAD ACROSS THE
AREA THIS MORNING IN THE WAKE OF A WARM FRONTAL PASSAGE.
PRECIPITATION SHOULD GRADUALLY END FROM WEST TO EAST DURING THE
AFTERNOON WITH PARTIAL CLEARING. VFR CONDITIONS PREVAIL WITH MVFR
CONDITIONS DUE TO LOW CEILINGS IN THE VICINITY OF SHOWERS.
MOUNTAINS OBSCURED AT TIMES THROUGH 18Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  53  38  51  34 /  30  10  20  10
CTB  48  35  49  32 /  30  10  10  10
HLN  48  33  45  31 /  30  10  20  20
BZN  43  26  41  25 /  20  10  40  20
WEY  38  21  34  22 /  20  10  30  40
DLN  46  32  41  28 /  10   0  20  20
HVR  40  29  51  30 /  40  20  20  10
LWT  42  33  45  28 /  30  10  20  10

&&

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

$$

WEATHER.GOV/GREATFALLS


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