177
FXUS65 KTFX 131040
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
340 AM MST SAT DEC 13 2025
KEY MESSAGES
- LIGHT SNOW ACROSS NORTH-CENTRAL MONTANA ENDS THIS MORNING.
- COLD TEMPERATURES LINGER ACROSS THE NORTH-CENTRAL MONTANA
PLAINS TODAY WITH MILDER TEMPERATURES MOVING IN TONIGHT
THROUGH SUNDAY.
- MILD BUT VERY WINDY CONDITIONS ARE EXPECTED TO DEVELOP BY EARLY NEXT
WEEK WITH STRONG WINDS POSSIBLE AS EARLY AND MONDAY ACROSS
PORTIONS OF NORTH-CENTRAL MONTANA.
- A PARTICULARLY STRONG AND WIDESPREAD PERIOD OF WIND IS POSSIBLE
IN ASSOCIATION WITH A FRONTAL PASSAGE ON WEDNESDAY.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THE SNOW EVENT ACROSS EASTERN PORTIONS OF NORTH-CENTRAL MT IS ENDING
EARLY THIS MORNING AS LARGER SCALE FORCING EXITS THE AREA AND WINTER
WEATHER HAZARD STATEMENTS ARE SET TO EXPIRE AT 5 AM. A FEW AREAS OF
VERY LIGHT SNOW OR FLURRIES MAY PERSIST THROUGH MID-DAY ACROSS NORTH-
CENTRAL MT AS MOISTURE CONTINUES TO OVERRUN THE LOW LEVEL COLD
AIRMASS THAT REMAINS IN PLACE FOR NOW ACROSS THE PLAINS.
UPPER LEVEL RIDGING CENTERED ALONG THE WEST COAST SHIFTS INLAND
LATER TODAY AND ACROSS THE NORTHERN ROCKIES TONIGHT. MILD AIR
ALREADY IN PLACE ACROSS SOUTHWEST MT AND ALONG THE CONTINENTAL DIVIDE
WILL BEGIN TO REPLACE THE COLDER AIRMASS ACROSS NORTH-CENTRAL MT
LATER THIS AFTERNOON AND EVENING WITH A SLOWER EROSION OF THE
SHALLOW COLD AIR LIKELY FOR AREAS ALONG THE HI-LINE.
A WESTERLY FLOW OF PACIFIC AIR MAINTAINS WELL ABOVE AVERAGE
TEMPERATURES ACROSS THE REGION THROUGH EARLY NEXT WEEK WITH
ATTENTION TURNING TO WINDS AS THE ALREADY FAST MID-LEVEL FLOW FLOW
ACROSS THE ROCKIES INCREASES TO SUPPORT STRONG WINDS INITIALLY ALONG
THE ROCKY MTN FRONT AS EARLY AS LATE SUNDAY. SURFACE LOW PRESSURE
AND A MID-LEVEL SHORTWAVE TRACKING ACROSS SOUTHERN AB/SK MONDAY
NIGHT ARE LIKELY TO SPREAD STRONGER WINDS ACROSS A LARGER PORTION OF
NORTH-CENTRAL MT LATER MONDAY AND MONDAY NIGHT. A POTENTIALLY
STRONGER WAVE MOVING ACROSS THE AREA WEDNESDAY LOOKS TO BRING THE
MOST WIDESPREAD POTENTIAL FOR STRONG WINDS ALONG WITH THE PASSAGE OF
PACIFIC COLD FONT. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
AREAS FROM CUT BANK TO GREAT FALLS TO LEWISTOWN ARE LIKELY STAY IN
THE SHALLOW COLD AIR WITH TEMPS ONLY RISING TO THE TEENS THROUGH MID-
AFTERNOON BEFORE A FAIRLY QUICK TRANSITION TO WARMER TEMPS IN THE
30S OCCURS THIS EVENING.
THERE IS SOME POTENTIAL FOR BLOWING/DRIFTING OF SNOW WITH THE ONSET
OF BREEZY/GUSTY SOUTHWEST WINDS ON SUNDAY. THIS WOULD INITIALLY
AFFECT AREAS ALONG THE ROCKY MTN FRONT AND AREAS NORTHEAST OF THE
LITTLE BELTS AND HIGHWOODS BY SUNDAY AFTERNOON. FORTUNATELY, ABOVE
FREEZING TEMPERATURES ARE LIKELY TO SETTLE THE SNOWPACK ACROSS MOST
AREAS BEFORE STRONGER WINDS DEVELOP SUNDAY NIGHT AND MONDAY.
AFTERNOON TEMPERATURES IN THE 40S AND 50S SUNDAY AND MONDAY WILL
LIKELY LEAD TO A FAIRLY RAPID MELTING OF THE THE RECENT SNOW ACROSS
EASTERN PORTIONS OF NORTH-CENTRAL MT. THE MAIN IMPACT HERE WOULD BE
THE DEVELOPMENT OF STANDING WATER AND MUDDY CONDITIONS, ESPECIALLY
CONSIDERING INITIALLY FROZEN GROUND THAT WILL TAKE A BIT LONGER TO
THAW AND INITIALLY PREVENT INFILTRATION OF THE SNOWMELT.
HIGH WIND HAZARD PRODUCTS ARE LIKELY FOR WESTERN PORTIONS OF NORTH-
CENTRAL MT MONDAY AND TUESDAY WITH LATEST BLENDED MODEL GUIDANCE
GIVING A 50-70% PROBABILITY OF GUSTS IN EXCESS OF 55 MPH TO AREAS
WEST OF I-15 AND ALONG THE US-87 CORRIDOR FROM CASCADE COUNTY EAST
THROUGH JUDITH BASIN COUNTY.
THE WEDNESDAY SYSTEM BEARS WATCHING WITH MODELS TRENDING TOWARD A
FAIRLY POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW PRESSURE MOVING
BY NORTH OF THE BORDER. WINDS ALOFT MAY SUPPORT A FAIRLY WIDESPREAD
WIND EVENT WITH INDICATIONS OF A STRONGER PACIFIC FRONTAL PASSAGE
THAT WOULD PROMOTE MIXING OF THE FAIRLY STRONG WINDS ALOFT AND
SUPPORT THE POTENTIAL FOR CONVECTIVE SNOW SHOWERS. HOENISCH
AVIATION
13/06Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS THE KBZN, KEKS, KHLN, AND KGTF
TERMINALS DURING THIS TAF PERIOD. AT THE KHVR, KCTB, AND KLWT
TERMINALS SNOW AND/OR LOW CEILINGS WILL REDUCE FLIGHT CATEGORY TO
AT LEAST MVFR-LEVELS FOR AT LEAST THE FIRST 8 HOURS OF THIS TAF
PERIOD. AT THE KGTF TERMINAL THERE IS A 20 - 30% CHANCE FOR SNOW
BETWEEN 13/07Z AND 13/18Z. THERE WILL BE ISOLATED INSTANCES OF
LOW-LEVEL WIND SHEAR AND MOUNTAIN WAVE TURBULENCE THROUGH 13/18Z
ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THERE
WILL ALSO BE INSTANCES OF MOUNTAIN OBSCURATION ACROSS NORTH-
CENTRAL MONTANA THROUGH AT LEAST 13/18Z. -IG
PRELIMINARY POINT TEMPS/POPS
GTF 25 21 49 39 / 20 0 0 0
CTB 18 14 45 32 / 10 0 0 0
HLN 43 28 50 32 / 10 0 0 0
BZN 49 27 53 28 / 0 0 0 0
WYS 39 12 44 14 / 0 0 0 0
DLN 51 29 53 29 / 0 0 0 0
HVR 5 1 44 30 / 10 0 0 0
LWT 32 22 48 34 / 30 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
WINTER STORM WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR BEARS
PAW MOUNTAINS AND SOUTHERN BLAINE-EASTERN TOOLE AND LIBERTY-
FERGUS COUNTY BELOW 4500FT-HILL COUNTY-NORTHERN BLAINE COUNTY-
WESTERN AND CENTRAL CHOUTEAU COUNTY.
WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
EASTERN GLACIER, WESTERN TOOLE, AND CENTRAL PONDERA-NORTHERN
HIGH PLAINS.
COLD WEATHER ADVISORY UNTIL 10 AM MST THIS MORNING FOR NORTHERN
BLAINE COUNTY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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