863
FXUS65 KTFX 120608
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1108 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.
UPDATE
/ISSUED 733 PM MST THU DEC 11 2025/
SNOWFALL BANDS HAVE BEGUN TO DEVELOP ACROSS NORTH CENTRAL MONTANA,
WITH THE MOST PROMINENT ONE CURRENTLY SOUTH OF GREAT FALLS,
THOUGH THERE ARE SOME ADDITIONAL CONVECTIVE TYPE SNOW SHOWERS
ALONG THE MONTANA HI-LINE THIS EVENING. FURTHER SOUTH, SUBFREEZING
TEMPERATURES HAVE SETTLED INTO THE HELENA VALLEY, THOUGH WARMER
AIR REMAINS ALOFT. A FEW RAIN SHOWERS MAY SURVIVE THE TREK ACROSS
THE CONTINENTAL DIVIDE AND PRODUCE SOME RAIN SHOWERS IN THE
VALLEY, WHICH MAY FREEZE TO TREES, BRIDGES, AND OVERPASSES, BUT
GROUND TEMPERATURES SHOULD REMAIN ABOVE FREEZING LONG ENOUGH TO
PREVENT WIDESPREAD ACCRETIONS OF ICE ON ROADS AND SIDEWALKS. AS
SUCH, I HAVE ADDRESSED THIS WITH A SPECIAL WEATHER STATEMENT
INSTEAD OF ISSUING A WINTER WEATHER ADVISORY AT THIS TIME, BUT
WILL CONTINUE TO EVALUATE THE SITUATION THROUGH THE EVENING.
LUDWIG
DISCUSSION
/ISSUED 733 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
12/06Z TAF PERIOD
THE SHALLOW LEADING EDGE OF A DEEPER COLD AIRMASS IN PLACE ACROSS
THE NORTH-CENTRAL MT PLAINS HAS PUSHED AS FAR SOUTH AS TOSTON WITH
COLDER AIR POTENTIALLY TRICKLING INTO THE GALLATIN VALLEY AND
KBZN BY EARLY FRIDAY MORNING. MVFR CONDITIONS ARE WIDESPREAD
ACROSS AREA TAF SITES WITH IFR CONDITIONS BECOMING MORE LIKELY
LATER TONIGHT THROUGH FRIDAY MORNING ACROSS N-CENTRAL MT AS A
STEADIER AREA OF WIDESPREAD PRECIPITATION LIFTS NORTH AND
INTENSIFIES. WHILE PRECIPITATION TYPE IS PRIMARILY SNOW ACROSS
NORTH-CENTRAL MT, FREEZING RAIN IS OCCURRING IN KHLN AND LIKELY TO
PERSIST INTO FRIDAY MORNING WITH LOWER CONFIDENCE IN POTENTIAL
FOR -FZRA AT KBZN . HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 56 2 11 5 / 80 80 90 50
CTB 51 -4 4 -2 / 40 50 90 90
HLN 57 21 34 26 / 80 90 80 10
BZN 59 33 45 33 / 50 80 70 10
WYS 41 29 37 21 / 30 50 50 10
DLN 57 41 51 33 / 10 10 10 0
HVR 39 -7 0 -8 / 70 60 90 100
LWT 49 5 10 4 / 100 100 100 70
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 UNTIL 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 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 UNTIL 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.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST FRIDAY NIGHT FOR
HELENA VALLEY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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