099
FXUS65 KTFX 120000
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
500 PM MST THU DEC 11 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- TEMPERATURES WELL BELOW NORMAL OVER THE PLAINS OF CENTRAL AND
NORTH CENTRAL MONTANA ON FRIDAY, WITH ABOVE NORMAL HIGHS IN THE
VALLEYS OF SOUTHWEST MONTANA.
- MODERATE TO HEAVY SNOW DEVELOPS OVERNIGHT TONIGHT AND THROUGH
THE DAY ON FRIDAY OVER CENTRAL AND NORTH CENTRAL, ESPECIALLY
EAST OF THE I-15 CORRIDOR.
- SEVERAL DAYS OF WINDY CONDITIONS ARE EXPECTED NEXT WEEK OVER
NORTH CENTRAL MT.
DISCUSSION
/ISSUED 246 PM MST THU DEC 11 2025/
- METEOROLOGICAL OVERVIEW:
THE ARCTIC FRONT, WHICH SURGED SOUTH ACROSS THE PLAINS OF NORTH
CENTRAL AND CENTRAL MONTANA BETWEEN 15-18Z THIS MORNING, WILL
CONTINUE TO PROGRESS (ALBEIT SLOWER AND MODIFIED WITH RESPECT TO
TEMPERATURES) SOUTH TOWARDS THE US HWY 12 CORRIDOR IN CENTRAL
MONTANA THROUGH THE REMAINDER OF THE AFTERNOON AND EARLY EVENING
HOURS BEFORE STALLING. STRONG LOW LEVEL FRONTOGENESIS ASSOCIATED
WITH THIS FRONT COMBINED WITH PACIFIC MOISTURE OVERRUNNING THE
ARCTIC AIRMASS WAS HELPING TO SUPPORT SCATTERED BANDS OF
PRECIPITATION LARGELY IN THE FORM OF SNOW OVER THE PLAINS AND
MOUNTAINS OF NORTH CENTRAL AND CENTRAL MONTANA; HOWEVER, BRIEF
PERIODS OF RAIN OR FREEZING RAIN WERE OCCURRING ALONG THE IMMEDIATE
FRONTAL BOUNDARY. THIS FREEZING RAIN THREAT WILL GRADUALLY SUBSIDE
THROUGH THE REMAINDER OF THE AFTERNOON HOURS AS TEMPERATURES ALOFT
COOL AND THE ARCTIC AIRMASS DEEPENS.
AS THE BEST FORCING SHIFTS SOUTH WITH THE FRONT PRECIPITATION WILL
TEMPORARY END FROM NORTH TO SOUTH THROUGH THE AFTERNOON HOURS TODAY,
WITH MOST OF PRECIPITATION BEING FOCUSED SOUTH OF THE MONTANA HWY
200 CORRIDOR AND NORTH OF THE US HWY 12 CORRIDOR THROUGH THE EVENING
HOURS TONIGHT. BY THE LATE EVENING HOURS TONIGHT A MID-LEVEL WARM
FRONT WILL THEN BEGIN TO LIFT NORTH TO NORTHEAST OVER THE ARCTIC
AIRMASS THAT IS IN PLACE. THIS NORTHWARD PROGRESSION OF THE MID-
LEVEL WARM FRONT WILL HELP TO REORIENT THE BAND OF SNOW ACROSS
CENTRAL MONTANA BACK TO THE NORTH AND OVER NORTH CENTRAL MONTANA
IN NORTHWEST TO SOUTHEAST ORIENTATION THROUGH THE DAY ON FRIDAY.
THE NORTHWARD PROGRESSION (I.E. SPEED) OF THIS MID-LEVEL WARM
FRONT WILL STRONGLY DICTATE HOW MUCH SNOW EVENTUALLY FALLS ACROSS
PORTIONS OF CENTRAL AND NORTH CENTRAL MONTANA (I.E. SLOWER
PROGRESSION WILL ALLOW FOR MORE SNOW WHILE A FASTER PROGRESSION
WILL LEAD TO LESS SNOW), ESPECIALLY ALONG AND WEST OF THE I-15
CORRIDOR TO THE ROCKY MOUNTAIN FRONT WHERE LOW-LEVEL DRYING DUE
WESTERLY FLOW ALOFT WILL BE OCCURRING. SNOW WILL GRADUALLY END
FROM SOUTHWEST TO NORTHEAST FROM THE LATE AFTERNOON/EARLY EVENING
(CENTRAL MONTANA) HOURS ON FRIDAY TO THE EARLY MORNING HOURS ON
SATURDAY (NORTH CENTRAL MONTANA). - MOLDAN
- FORECAST CONFIDENCE & SCENARIOS:
ACCUMULATING SNOW THROUGH FRIDAY/FRIDAY NIGHT...
HIGH END SNOWFALL (10% CHANCE OF OCCURRING) : A SLOWER MOVING MID-
LEVEL WARM FRONT HELPS TO SUPPORT A PROLONGED PERIOD OF MODERATE TO
HEAVY SNOW ACROSS ALL OF THE PLAINS OF CENTRAL AND NORTH CENTRAL
MONTANA, WITH SNOWFALL AMOUNTS APPROACHING 12" OVER THE PLAINS OF
CENTRAL AND NORTH CENTRAL MONTANA EAST OF THE I-15 CORRIDOR AND 12-
20" IN THE MOUNTAINS OF CENTRAL AND NORTH CENTRAL MONTANA.
LOW END SNOWFALL (10% CHANCE OF OCCURRING) : A FASTER MOVING MID-
LEVEL WARM FRONT LIMITS THE TIME FOR MODERATE TO HEAVY SNOW,
ESPECIALLY ALONG THE I-15 CORRIDOR WHERE DOWNSLOPING WESTERLY WINDS
LEAD TO SNOW ACCUMULATION OF GENERALLY LESS THAN 1". ACROSS THE
REMAINDER OF THE PLAINS TO THE EAST SNOWFALL ACCUMULATIONS GENERALLY
RANGE FROM 2-5", WITH 5-10" IN THE MOUNTAINS. - MOLDAN
STRONG WINDS EARLY NEXT WEEK...THERE IS ALREADY AND 80 PERCENT
CHANCE THAT WINDS COULD EXCEED WARNING CRITERIA ALONG THE ROCKY
MOUNTAIN FRONT AND IN THE CUT BANK AREA MON AND TUE AND A 60 PERCENT
CHANCE ON WED. BRUSDA
AVIATION
12/00Z TAF PERIOD
KGTF/KCTB/KHVR/KLWT
BANDS OF LIGHT TO MODERATE SN WILL CONTINUE TO DRIFT ACROSS THE
PLAINS THIS EVENING AND OVERNIGHT TONIGHT, PARTICULARLY AT KLWT
AND KGTF, BRINGING SOME PERIODS OF IFR TO LIFR CONDITIONS.
SNOWFALL BANDS WILL CONCENTRATE TOMORROW ALONG AN ELEVATED WARM
FRONT, BRINGING A PERIOD OF VERY HEAVY SNOW WITH IT WITH VLIFR
CONDITIONS POSSIBLE. THIS BAND MAY FORM AS EARLY AS 10Z, BUT I
BEGAN IT AROUND 12Z AT KCTB AND KGTF IN A PROB30 GROUP AND
PROGRESSED IT NORTH AND EAST THROUGH THE DAY. KLWT MAY BE IMPACTED
FOR A PARTICULARLY LONG PERIOD OF TIME DURING THE DAY TOMORROW,
BUT THE MOVEMENT OF THIS BAND IS STILL A BIT UNCERTAIN.
KHLN/KBZN/KEKS
EXPECT PERIODS OF MVFR TO IFR CONDITIONS AS RAIN AND SNOW SHOWERS
PROGRESS THROUGH THE AREA. SN IS MOST LIKELY TO BRING IFR
CONDITIONS TO KHLN OVERNIGHT TONIGHT AS A COLD FRONT LINGERS IN
THE AREA. LOWERED CEILINGS (LOW VFR TO HIGH MVFR) WILL BE AROUND
THE AREA THROUGH THE TAF PERIOD, ALONG WITH MOUNTAIN OBSCURATION.
LUDWIG
PRELIMINARY POINT TEMPS/POPS
GTF 2 11 5 29 / 80 90 50 10
CTB -4 4 -2 22 / 50 90 90 0
HLN 21 34 26 43 / 90 80 10 10
BZN 33 45 33 46 / 80 70 10 10
WYS 29 37 21 37 / 50 50 10 10
DLN 41 51 33 49 / 10 10 0 0
HVR -7 0 -8 6 / 60 90 100 10
LWT 5 10 4 29 / 100 100 70 20
TFX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL 10 AM MST FRIDAY FOR EASTERN
GLACIER, WESTERN TOOLE, AND CENTRAL PONDERA-EASTERN TOOLE AND
LIBERTY-HILL COUNTY-NORTHERN BLAINE COUNTY.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 5 AM MST SATURDAY
FOR FERGUS COUNTY BELOW 4500FT-JUDITH BASIN COUNTY AND JUDITH
GAP.
WINTER WEATHER ADVISORY FROM 4 AM FRIDAY TO 5 AM MST SATURDAY
FOR EASTERN GLACIER, WESTERN TOOLE, AND CENTRAL PONDERA-EASTERN
PONDERA AND EASTERN TETON-NORTHERN HIGH PLAINS.
WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR BEARS
PAW MOUNTAINS AND SOUTHERN BLAINE-WESTERN AND CENTRAL CHOUTEAU
COUNTY.
WINTER STORM WARNING FROM 4 AM FRIDAY TO 5 AM MST SATURDAY FOR
BEARS PAW MOUNTAINS AND SOUTHERN BLAINE-EASTERN TOOLE AND
LIBERTY-HILL COUNTY-NORTHERN BLAINE COUNTY-WESTERN AND CENTRAL
CHOUTEAU COUNTY.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM MST FRIDAY
FOR EAST GLACIER PARK REGION-LITTLE BELT AND HIGHWOOD MOUNTAINS-
SNOWY AND JUDITH MOUNTAINS-SOUTHERN ROCKY MOUNTAIN FRONT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR FERGUS
COUNTY BELOW 4500FT-JUDITH BASIN COUNTY AND JUDITH GAP-LITTLE
BELT AND HIGHWOOD MOUNTAINS-SNOWY AND JUDITH MOUNTAINS-SOUTHERN
ROCKY MOUNTAIN FRONT.
WINTER WEATHER ADVISORY UNTIL 6 PM MST FRIDAY FOR BIG BELT,
BRIDGER AND CASTLE MOUNTAINS-CASCADE COUNTY BELOW 5000FT-GATES
OF THE MOUNTAINS-MEAGHER COUNTY VALLEYS-SOUTHERN HIGH PLAINS-
UPPER BLACKFOOT AND MACDONALD PASS.
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