700
FXUS65 KTFX 121110
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
410 AM MST FRI DEC 12 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- ICY CONDITIONS ARE EXPECTED DUE TO FREEZING RAIN AND SNOW ACROSS
LEWIS AND CLARK AND BROADWATER COUNTIES THIS MORNING.
- SNOW INCREASES ACROSS NORTH-CENTRAL MONTANA THIS MORNING WITH MODERATE
TO HEAVY SNOW EXPECTED ACROSS EASTERN PORTIONS OF NORTH-
CENTRAL MONTANA INTO THIS EVENING.
- A COLD AIRMASS REMAINS OVER THE PLAINS THROUGH SATURDAY BEFORE
WINDY AND WARMER CONDITIONS REDEVELOP LATE THIS WEEKEND INTO
EARLY NEXT WEEK.
DISCUSSION
/ISSUED 346 AM MST FRI DEC 12 2025/
- METEOROLOGICAL OVERVIEW:
DEEP UPPER LEVEL TROUGHING ACROSS CANADA BROUGHT AN ARCTIC AIRMASS
SOUTH ACROSS THE NORTH-CENTRAL MT PLAINS YESTERDAY WITH SHALLOW COLD
AIR TRICKLING SOUTH THROUGH THE HELENA VALLEY AND CANYON FERRY AREA
OVERNIGHT AS WELL AS ACROSS THE CONTINENTAL DIVIDE NEAR ROGERS PASS
THROUGH LINCOLN. MEANWHILE UPPER LEVEL RIDGING REMAINS IN PLACE OFF
THE WEST COAST WITH MILD AIR REMAINING ACROSS SOUTHWEST MT WHILE A
PLUME OF PACIFIC MOISTURE CONTINUES TO STREAM OVER THE RIDGE AND
ACROSS CENTRAL AND NORTH-CENTRAL MT. AN AREA OF WIDESPREAD
PRECIPITATION ACROSS CENTRAL MT EARLY THIS MORNING WILL LIFT NORTH
TODAY AND INTENSIFY AS THE UPPER RIDGE BEGINS TO SHIFT INLAND AND
DEEPER MOISTURE OVERRUNS THE COLD AIRMASS.
FREEZING RAIN THAT OCCURRED OVERNIGHT FROM LINCOLN SOUTHEAST THROUGH
HELENA AND TOWNSEND HAS LARGELY CHANGED TO SNOW EARLY THIS MORNING AS
THE COLD AIR DEEPENED SOMEWHAT, BUT MID LEVEL WARMING IS LIKELY TO
CHANGE PRECIPITATION BACK TO FREEZING RAIN FOR PERIOD THIS MORNING
BEFORE THE PRECIPITATION LIFTS NORTHWARD OF THIS AREA BY THIS
AFTERNOON. FURTHER NORTH, THE BEST FORCING FOR MODERATE TO HEAVY
SNOWFALL IS EXPECTED TO DEVELOP FROM TOOLE COUNTY SOUTHEAST THROUGH
CHOTEAU AND FERGUS COUNTIES THIS AFTERNOON, SHIFTING NORTHWARD HILL
AND BLAINE COUNTIES THIS EVENING.
AS THE UPPER LEVEL RIDGE CONTINUES TO SHIFT INLAND THIS WEEKEND, THE
COLD AIRMASS WILL RETREAT BACK TO THE NORTH WITH MILD AND WINDY
CONDITIONS OVERSPREADING THE ENTIRE AREA BY SUNDAY AND CONTINUING
THROUGH AT LEAST MONDAY. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
AN ICE STORM WARNING HAS BEEN ISSUED FOR THE UPPER BLACKFOOT, HELENA
AND CANYON FERRY AREAS WHERE ROADS MAY BE PARTICULARLY ICY THIS
MORNING. SNOW MAY CONCEAL THE ICE IN SOME AREAS AND ADDITIONAL ICING
IS EXPECTED AS PRECIPITATION CHANGES BACK TO FREEZING RAIN WITH ROAD
AND AIR TEMPERATURES REMAINING IN THE TEENS IN THESE AREAS THIS
MORNING.
FORE SNOWFALL AMOUNTS AND WINTER WEATHER HAZARDS ACROSS NORTH-
CENTRAL MT REMAIN ON TRACK FROM PREVIOUS FORECASTS WITH HEAVIEST
SNOWFALL AMOUNTS LIKELY ALONG AN AXIS FROM LIBERTY AND HILL COUNTIES
SOUTHEAST THROUGH FERGUS COUNTY. HOENISCH
AVIATION
12/12Z TAF PERIOD
MVFR CONDITIONS REMAIN WIDESPREAD ACROSS MOST TAF SITES TODAY WITH
IFR CONDITIONS BECOMING MORE WIDESPREAD THIS 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, A SWITCH BACK TO FREEZING RAIN IS LIKELY
AT KHLN THIS MORNING WITH LOWER CONFIDENCE IN POTENTIAL FOR -FZRA
AT KBZN. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 11 5 37 20 / 100 50 10 0
CTB 4 0 29 13 / 80 70 0 0
HLN 39 25 44 29 / 90 20 10 0
BZN 49 33 48 26 / 60 10 0 0
WYS 40 20 39 12 / 40 0 0 0
DLN 53 33 52 28 / 10 0 0 0
HVR 0 -8 7 0 / 100 100 10 0
LWT 14 2 34 23 / 100 70 20 0
TFX WATCHES/WARNINGS/ADVISORIES
COLD WEATHER ADVISORY UNTIL 10 AM MST THIS MORNING 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 BEARS PAW
MOUNTAINS AND SOUTHERN BLAINE-EASTERN TOOLE AND LIBERTY-FERGUS
COUNTY BELOW 4500FT-HILL COUNTY-JUDITH BASIN COUNTY AND JUDITH
GAP-NORTHERN BLAINE COUNTY-WESTERN AND CENTRAL CHOUTEAU COUNTY.
WINTER WEATHER ADVISORY UNTIL 5 AM MST SATURDAY FOR EASTERN
GLACIER, WESTERN TOOLE, AND CENTRAL PONDERA-EASTERN PONDERA AND
EASTERN TETON-NORTHERN HIGH PLAINS.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR EAST
GLACIER PARK REGION-LITTLE BELT AND HIGHWOOD MOUNTAINS-SNOWY AND
JUDITH MOUNTAINS-SOUTHERN ROCKY MOUNTAIN FRONT.
ICE STORM WARNING UNTIL 10 AM MST THIS MORNING FOR CANYON FERRY
AREA-HELENA VALLEY-UPPER BLACKFOOT AND MACDONALD PASS.
WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR BIG
BELT, BRIDGER AND CASTLE MOUNTAINS-CASCADE COUNTY BELOW 5000FT-
GATES OF THE MOUNTAINS-MEAGHER COUNTY VALLEYS-SOUTHERN HIGH
PLAINS.
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