261
FXUS65 KTFX 040322
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
822 PM MST WED DEC 3 2025
KEY MESSAGES
- WIDESPREAD SNOW EXPECTED THURSDAY EVENING THROUGH SATURDAY
AFTERNOON WITH THE HEAVIEST AMOUNTS IN THE MOUNTAINS.
- AN ACTIVE PATTERN CONTINUES THROUGH NEXT WEEK WITH WARMER AND
WINDIER CONDITIONS POSSIBLE.
UPDATE
TONIGHT, NORTHWEST FLOW ALOFT BRINGING DOWN MINI VORTICITY WAVES
WILL BRING LIGHT SNOW TO THE MOUNTAINS. AT LOWER ELEVATIONS,
PATCHY FOG HAVE DEVELOPED ALONG THE HI-LINE. WITH WINDS PICKING UP
OVERNIGHT, I AM NOT TOO CONCERNED WITH MUCH MORE DEVELOPMENT OF
FOG. ANY CURRENT FOG WILL DISSIPATE LATER IN THE NIGHT WHEN
BREEZY WINDS SETTLE IN. GUSTY WINDS DEVELOP ALONG THE ROCKY
MOUNTAIN FRONT OVERNIGHT AND CONTINUE THROUGH THE DAY THURSDAY.
THE FIRST MINI SHORTWAVE MOVES THROUGH THURSDAY MORNING,
INCREASING CHANCES FOR LIGHT SNOW ACROSS THE REGION. -WILSON
DISCUSSION
/ISSUED 426 PM MST WED DEC 3 2025/
- METEOROLOGICAL OVERVIEW:
CALM CONDITIONS WILL CONTINUE THROUGH THE REST OF TODAY WITH
INCREASING CLOUD COVER EXPECTED AS THE EVENING PROGRESSES.
THURSDAY WILL START OFF DRY BEFORE THE FIRST SHORTWAVE TROUGH
MOVES OVER THE AREA IN THE AFTERNOON KICKING OFF THE INITIAL
SNOWFALL THAT WILL PRIMARILY FOCUS ON THE MOUNTAINS. ON FRIDAY,
A SECOND, STRONGER SHORTWAVE WILL MOVE INTO THE REGION BRINGING A
CHANCE FOR MORE WIDESPREAD SNOW AT LOWER ELEVATIONS FRIDAY NIGHT
INTO SATURDAY AFTERNOON. THE COMBINATION OF THESE TWO SHORTWAVES
OVER THE TWO DAY PERIOD WILL ALLOW FOR HEAVY SNOW IN THE MOUNTAINS
AND LIGHTER BUT STILL IMPACTFUL SNOW AT LOWER ELEVATIONS ACROSS
MOST OF THE REGION.
NORTHWEST FLOW ALOFT CONTINUES THROUGH THE START OF NEXT WEEK
ALLOWING FOR UNSETTLED CONDITIONS TO CONTINUE THROUGH AT LEAST
LAST WEDNESDAY. ADDITIONALLY, THERE IS GROWING CONFIDENCE IN
STRONGER CHINOOK WINDS ALONG THE ROCKY MOUNTAIN FRONT EARLY NEXT
WEEK WHICH IS EXPECTED TO BRING SOME WARMER TEMPERATURES BACK TO
THE LOWER ELEVATIONS OF NORTH-CENTRAL MONTANA.
- FORECAST CONFIDENCE & SCENARIOS:
LOWER ELEVATION SNOW THURSDAY THROUGH SATURDAY:
LIGHT LOWER ELEVATION SNOW IS POSSIBLE WITH THE THURSDAY SHORTWAVE
BUT THE MAIN EVENT FOR LOWER ELEVATIONS WILL BE FRIDAY AFTERNOON
THROUGH SATURDAY AFTERNOON WITH THE ARRIVAL OF THE SECOND
SHORTWAVE. WITH THE SECOND SYSTEM, A WIDESPREAD 1-2 INCHES IS
POSSIBLE ACROSS A GOOD PORTION OF NORTH-CENTRAL MONTANA EXCEPT THE
GOLDEN TRIANGLE WHICH IS SET TO MISS MOST OF THE SNOWFALL WITH
THIS EVENT. AS OF RIGHT NOW, THERE ARE A COUPLE AREAS ALONG THE
LOWER ELEVATIONS WHICH WOULD BE CANDIDATES FOR HIGHER SNOWFALL
AMOUNTS, PARTICULARLY ALONG THE HIGHWAY 200 CORRIDOR BETWEEN GREAT
FALLS AND LEWISTOWN, THE SMITH RIVER VALLEY, AND THE GALLATIN
VALLEY. CONFIDENCE WAS NOT HIGH ENOUGH TO ADD THEM TO THE INITIAL
WINTER STORM WATCH BUT THESE AREAS WILL NEED TO BE MONITORED WITH
FUTURE UPDATES AS INCREASES IN SNOWFALL AMOUNTS COULD JUSTIFY
ADDING THESE ZONES TO THE WATCH OR EVENTUAL WARNING. BUT OTHERWISE
MOST OF THE LOWER ELEVATION SNOWFALL LOOKS TO BE ADVISORY LEVEL
AT THIS POINT WITH ONLY MINOR IMPACTS EXPECTED.
HEAVY MOUNTAIN SNOW THURSDAY THROUGH SATURDAY:
CONFIDENCE CONTINUES TO INCREASE IN THE POTENTIAL FOR SIGNIFICANT
SNOWFALL ALONG THE MOUNTAINS OF CENTRAL AND SOUTHWEST MONTANA WITH
THE GREATEST IMPACTS EXPECTED ALONG THE CONTINENTAL DIVIDE AND
RANGES OF CENTRAL AND SOUTHWEST MONTANA. AS SUCH A WINTER STORM
WATCH HAS BEEN ISSUED FOR THURSDAY EVENING THROUGH SATURDAY
AFTERNOON. BROADLY SPEAKING, 6 TO 12 INCHES IS POSSIBLE WITH THE
RIDGETOPS POTENTIALLY SEEING AMOUNTS GREATER THAN A FOOT.
TRAVEL IMPACTS THURSDAY THROUGH SATURDAY:
BY FAR, ONE OF THE BIGGEST CONCERNS WITH THIS SYSTEM WILL BE THE
TIMING AND HOW IT IMPACTS THE THURSDAY EVENING, FRIDAY MORNING,
AND FRIDAY EVENING COMMUTES. WITH THE INITIAL SNOWFALL ON
THURSDAY, DEPENDING ON ROAD TEMPERATURES, THERE WILL LIKELY BE
SOME INITIAL MELTING OF THE FIRST FEW FLAKES. WHEN THIS MOISTURE
REFREEZES AS THE NIGHT GOES ON THE CONCERN WILL BE PATCHES OF ICE
FORMING AND THEN RECEIVING MORE SNOW AS THE EVENT CONTINUES
CREATING VERY SLICK ROADS. ADDITIONALLY, SOME PERIODS OF MODERATE
TO HEAVY SNOWFALL ARE POSSIBLE PARTICULARLY WITH THE INITIAL PUSH
ON THURSDAY EVENING AND AGAIN WITH THE ARRIVAL OF THE SECOND
SHORTWAVE ON FRIDAY AFTERNOON/EVENING. THIS COULD LEAD TO PERIODS
OF REDUCED VISIBILITY WHICH WILL ADD TO THE POTENTIAL FOR
HAZARDOUS DRIVING CONDITIONS.
IN PARTICULAR, THERE IS GREAT CONCERN REGARDING THE IMPACTS
POSSIBLE ALONG I-90 FROM BELGRADE TO BOZEMAN PASS. SNOWFALL
PROBABILITIES IN BOZEMAN PROPER WERE NOT ENOUGH TO WARRANT
INCLUDING GALLATIN VALLEY IN THE WINTER STORM WATCH BUT MINOR TO
MODERATE IMPACTS ARE STILL POSSIBLE IN THE AREA DUE TO SLICK ROADS
AND BRIEF PERIODS OF MODERATE TO HEAVY SNOWFALL, PARTICULARLY ON
THE FAR EASTERN SIDE OF THE GALLATIN VALLEY HEADING TOWARDS THE
PASS.
ADDITIONAL MOUNTAIN PASSES AND ROADS THAT MIGHT EXPERIENCE
SIGNIFICANT IMPACTS INCLUDE, BUT ARE NOT LIMITED TO, MARIAS PASS,
KINGS HILL PASS, DEEP CREEK PASS, AND HIGHWAY 191 SOUTH OF BOZEMAN
TO THE IDAHO BORDER. IF HEADING OUT, MOTORISTS NEED TO BE PREPARED
FOR RAPIDLY CHANGING AND DETERIORATING ROAD AND WEATHER
CONDITIONS AND IT IS ADVISED TO CARRY CHAINS AS WELL AS AN
EMERGENCY KIT. -THOR
AVIATION
04/00Z TAF PERIOD
VFR CONDITIONS WILL LARGELY PREVAIL THROUGH THE 0400/0500 TAF
PERIOD, BUT INCREASING MID-LEVEL CLOUDINESS IS EXPECTED ACROSS
SOUTHWEST AND INTO PORTIONS OF CENTRAL MONTANA BEYOND 03Z THIS
EVENING AND THEN ACROSS THE REMAINDER OF CENTRAL MONTANA BY
FRIDAY MORNING/AFTERNOON. SNOW WILL BEGIN TO INCREASE IN AREAL
COVERAGE FRIDAY AFTERNOON OVER AND NEAR THE MOUNTAINS, MOST
NOTABLY NEAR THE KBZN, KEKS, KHLN, AND KGTF TERMINALS. FINALLY,
SOME INSTANCES OF LOW LEVEL WIND SHEAR CAN'T BE RULED OUT AS LOW
TO MID-LEVEL FLOW INCREASES, ESPECIALLY AT THE KLWT TERMINAL
BEYOND 06Z THURSDAY.
PRELIMINARY POINT TEMPS/POPS
GTF 23 38 24 35 / 0 30 30 50
CTB 21 35 20 30 / 0 20 10 40
HLN 21 36 26 38 / 10 40 40 60
BZN 14 33 23 36 / 10 50 50 50
WYS 9 24 15 30 / 30 80 80 80
DLN 18 36 23 40 / 0 20 30 40
HVR 10 35 18 30 / 10 20 20 40
LWT 18 36 21 34 / 0 30 40 40
TFX WATCHES/WARNINGS/ADVISORIES
WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH SATURDAY
AFTERNOON FOR EAST GLACIER PARK REGION-NORTHWEST BEAVERHEAD
COUNTY-SOUTHERN ROCKY MOUNTAIN FRONT.
WINTER STORM WATCH FROM THURSDAY AFTERNOON THROUGH LATE FRIDAY
NIGHT FOR BIG BELT, BRIDGER AND CASTLE MOUNTAINS-GALLATIN AND
MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS-LITTLE BELT
AND HIGHWOOD MOUNTAINS.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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