605
FXUS65 KTFX 151812
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1112 AM MST MON DEC 15 2025
AVIATION SECTION UPDATED.
KEY MESSAGES
- MILD TEMPERATURES CONTINUE EARLY THIS WEEK WITH MULTIPLE HIGH
WIND EPISODES EXPECTED THROUGH THE UPCOMING WEEK.
- STRONG WINDS DEVELOP TODAY ACROSS NORTH-CENTRAL MONTANA WITH
WIND SPEEDS PEAKING ALONG THE ROCKY MOUNTAIN FRONT THIS
AFTERNOON AND LATE THIS AFTERNOON THROUGH TONIGHT FURTHER EAST.
- A STRONG COLD FRONT ON WEDNESDAY WILL BRING ANOTHER PERIOD OF WIDESPREAD
AND POTENTIALLY DAMAGING WINDS TO MUCH OF THE AREA AS WELL AS
THE POTENTIAL FOR LOCALLY INTENSE SNOW SHOWERS.
UPDATE
/ISSUED 854 AM MST MON DEC 15 2025/
THE PRIMARY CONCERN FOR TODAY WILL CONTINUE TO BE PERIODS OF
STRONG, GUSTY WINDS THROUGH TUESDAY MORNING. H700 FLOW WILL
ROUGHLY RUN BETWEEN 60 AND 85 KTS WITH MOUNTAIN WAVES TRANSFERRING
THE STRONGEST WINDS TO THE SURFACE ALONG THE ROCKY MOUNTAIN FRONT
THIS AFTERNOON AND A SHORTWAVE PASSAGE BRINGING PEAK WINDS OVER
THE PLAINS THIS EVENING THROUGH EARLY TUESDAY.
WIND GUSTS LOOK TO EXCEED THE 75 TO 85 MPH RANGE AT TIMES ALONG
THE ROCKY MOUNTAIN FRONT AND THE PLAINS ALONG AND WEST OF HIGHWAY
89. SOME OF THE NORMALLY HIGHER WIND PRONE LOCATIONS SUCH AS THE
BYNUM, DEEP CREEK, AND EAST GLACIER AREAS MAY SEE GUSTS EXCEEDING
90 MPH. FARTHER EAST, WINDS WILL BE STRONGEST ALONG THE CENTRAL
MONTANA HIGHWAY 87/200 CORRIDOR IN CASCADE AND JUDITH BASIN
COUNTIES UNTIL THE EJECTING SHORTWAVE TROUGH BRINGS MORE
WIDESPREAD GUSTS IN THE 50 TO 70 MPH RANGE LATER THIS EVENING
THROUGH EARLY TUESDAY.
IMPACTS WILL INCLUDE DIFFICULT TO DANGEROUS TRAVEL FOR HIGH
PROFILE VEHICLES, LOCALIZED BLOWING DUST NEAR OPEN FIELDS, AND THE
MOVEMENT OF UNSECURED OUTDOOR ITEMS, INCLUDING CHRISTMAS
DECORATIONS. SOME ISOLATED POWER OUTAGES ALSO CAN'T RULED OUT,
PARTICULARLY FOR AREAS THAT OBSERVE THE HIGHER END GUSTS. - RCG
DISCUSSION
/ISSUED 854 AM MST MON DEC 15 2025/
- METEOROLOGICAL OVERVIEW:
FLAT UPPER LEVEL RIDGING EXISTS ACROSS THE WESTERN US DOWNSTREAM OF
TROUGHING IN THE NE PACIFIC WITH FAST MID-UPPER LEVEL WESTERLY FLOW
ACROSS THE NORTHERN ROCKIES AND MT. A PAIR OF SHORTWAVE DISTURBANCES
EJECTING OUT OF THE OFFSHORE TROUGH WILL PROGRESSIVELY FLATTEN THE
RIDGE THROUGH WEDNESDAY WITH SIGNIFICANT WIND EVENTS EXPECTED WITH
THE PASSAGE OF EACH WAVE, PARTICULARLY ON WEDNESDAY WITH THE MOST
WIDESPREAD/IMPACTFUL WINDS.
TEMPERATURES REMAIN WELL ABOVE AVERAGE TODAY WITH A FEW LOCATIONS
POTENTIALLY REACHING DAILY RECORDS AGAIN. IT'S WORTH MENTIONING
THAT DILLON IS NOW UP TO A 5 DAY STRETCH OF DAILY RECORD MAXIMUM
TEMPS WITH ANOTHER POSSIBLE TODAY. MAIN STORY HOWEVER WILL BE THE
DEVELOPMENT OF STRONG WINDS TODAY AS MID-LEVEL FLOW INCREASES
AHEAD OF THE INITIAL SHORTWAVE DISTURBANCE MOVING ONSHORE WITH
SURFACE LOW PRESSURE EMERGING IN CENTRAL AB LATE THIS AFTERNOON
AND TRACKING EAST WHILE THE SHORTWAVE TRANSLATES EAST ALONG THE
US/CANADIAN BORDER TONIGHT. AS MID-LEVEL FLOW INCREASES TODAY
STRONG WINDS WILL REDEVELOP ALONG THE ROCKY MOUNTAIN FRONT BEFORE
SPREADING EAST ACROSS MUCH OF NORTH-CENTRAL MT TONIGHT.
THERE IS A PERIOD OF SOMEWHAT DECREASED WINDS ON TUESDAY BEFORE THE
SECOND AND STRONGER WAVE APPROACHES THE AREA TUESDAY NIGHT. 700MB
WIND SPEEDS INCREASED TO 65-85KTS AS THIS WAVE MOVES ACROSS THE AREA
WEDNESDAY, SUPPORTING THE POTENTIAL FOR WIDESPREAD STRONG WINDS.
MEANWHILE, PACIFIC MOISTURE EMEBEDDED IN THE FLOW WILL INITIALLY BRING
PRECIPITATION TO AREAS ALONG THE CONTINENTAL DIVIDE NEAR GNP TODAY AND
TOMORROW WITH SNOW LEVELS REMAINING RELATIVELY HIGH. ADDITIONAL
MOISTURE ARRIVES WITH A PACIFIC COLD FRONT ON WEDNESDAY ALONG WITH
LOWERING SNOW LEVELS THROUGH SIGNIFICANT SNOWFALL IS MAINLY
LIMITED TO AREAS ALONG THE CONTINENTAL DIVIDE NORTH OF ROGERS PASS
TO THE CANADIAN BORDER. RAIN AND SNOW SHOWERS SPREAD EAST WITH
THE COLD FRONT ON WEDNESDAY WITH COOLING ALOFT PROVIDING ENOUGH
INSTABILITY FOR LOCALLY INTENSE SHOWERS. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
VERY FAVORABLE CONDITIONS FOR MOUNTAIN WAVE WIND ENHANCEMENT ARE
EXPECTED THIS AFTERNOON ALONG THE ROCKY MTN FRONT, INCLUDING A
STABLE/CRITICAL TEMP/WIND PROFILE ABOVE MOUNTAIN TOPS, WHICH WILL
SUPPORT THE POTENTIAL FOR GUST IN EXCESS OF 85 MPH THERE AND
POSSIBLY A FEW ISOLATED GUSTS TO AROUND 100 MPH IN THE MOST
TERRAIN FAVORED LOCATIONS ON THE EAST SLOPES. AS THIS INITIAL WIND
MAXIMUM TRANSLATES EAST THIS EVENING/OVERNIGHT, STRONGER GUSTS
SPREAD ACROSS NORTH-CENTRAL MT WITH ENOUGH LINGERING MOUNTAIN WAVE
SUPPORT FOR THE RISK OF ISOLATED GUSTS IN EXCESS OF 65-75 MPH
ACROSS AREAS DOWNSTREAM OF THE LITTLE BELTS INCLUDING JUDITH
BASIN COUNTY.
COOLING ALOFT ON WEDNESDAY WILL ALLOW FOR EFFECTIVE ATMOSPHERIC
MIXING ACROSS THE ENTIRE AREA WHICH WILL ALSO AID IN WEDNESDAY'S
STRONG WINDS BEING MORE WIDESPREAD AND OF LONGER DURATION (MULTIPLE
HOURS OF VERY WINDY CONDITIONS VS THE TYPICAL 1-3 HR PEAK PERIOD).
THIS AND THE NOTABLY SIGNIFICANT 850-700MB WIND SPEEDS (>90TH
CLIMATOLOGICAL PERCENTILE) HAS THE POTENTIAL TO PRODUCE A MORE
IMPACTFUL AND WIDESPREAD THAN AVERAGE WIND EVENT FOR THE AREA,
INCLUDING IN THE HELENA AND GALLATIN VALLEYS. HOENISCH
AVIATION
15/18Z TAF PERIOD
VFR CONDITIONS PREVAIL THROUGH THE TAF PERIOD. MOUNTAIN WAVE
TURBULENCE AND INSTANCES OF LOW LEVEL WIND SHEAR WILL INCREASE
TODAY AND TONIGHT AS WESTERLY FLOW ALOFT STRENGTHENS WITH GUSTY
WINDS IMPACTING MOST NORTH-CENTRAL MT TERMINALS THIS AFTERNOON
THROUGH TONIGHT. HOENISCH/THOR
HYDROLOGY
MILD DAYTIME AND OVERNIGHT TEMPERATURES WILL LEAD TO RAPID MELTING
OF THE RECENT SNOW ACROSS EASTERN PORTIONS OF NORTH-CENTRAL MT. WITH
INITIALLY FROZEN GROUND, MUCH OF THE SNOWMELT IS LIKELY TO REMAIN
ON THE SURFACE AND MAY LEAD TO STANDING WATER. WHILE OVERALL
IMPACT TO CREEK/STREAM LEVELS IS LOW, MOST CREEKS ARE LIKELY TO BE
FROZEN WITH POTENTIAL FOR WATER FLOW OVER THE ICE OR POTENTIALLY
BACK UP IN SOME CREEK BOTTOMS. HOENISCH
PRELIMINARY POINT TEMPS/POPS
GTF 60 41 52 41 / 10 0 10 20
CTB 55 34 45 33 / 10 10 10 40
HLN 51 37 52 35 / 10 20 20 40
BZN 54 37 55 36 / 10 10 10 10
WYS 39 24 40 31 / 10 20 30 50
DLN 54 37 54 35 / 10 10 10 20
HVR 44 30 44 30 / 20 0 10 30
LWT 51 34 46 34 / 10 0 10 10
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY EVENING
FOR BEARS PAW MOUNTAINS AND SOUTHERN BLAINE-BIG BELT, BRIDGER
AND CASTLE MOUNTAINS-CANYON FERRY AREA-CASCADE COUNTY BELOW
5000FT-EAST GLACIER PARK REGION-EASTERN GLACIER, WESTERN TOOLE,
AND CENTRAL PONDERA-EASTERN PONDERA AND EASTERN TETON-EASTERN
TOOLE AND LIBERTY-ELKHORN AND BOULDER MOUNTAINS-FERGUS COUNTY
BELOW 4500FT-GALLATIN VALLEY-GATES OF THE MOUNTAINS-HELENA
VALLEY-JUDITH BASIN COUNTY AND JUDITH GAP-LITTLE BELT AND
HIGHWOOD MOUNTAINS-MADISON RIVER VALLEY-MEAGHER COUNTY VALLEYS-
MISSOURI HEADWATERS-NORTHERN HIGH PLAINS-SNOWY AND JUDITH
MOUNTAINS-SOUTHERN HIGH PLAINS-SOUTHERN ROCKY MOUNTAIN FRONT-
UPPER BLACKFOOT AND MACDONALD PASS-WESTERN AND CENTRAL CHOUTEAU
COUNTY.
WINTER STORM WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
EVENING FOR EAST GLACIER PARK REGION-SOUTHERN ROCKY MOUNTAIN
FRONT.
HIGH WIND WARNING UNTIL 11 AM MST TUESDAY FOR BEARS PAW
MOUNTAINS AND SOUTHERN BLAINE-CASCADE COUNTY BELOW 5000FT-
EASTERN PONDERA AND EASTERN TETON-FERGUS COUNTY BELOW 4500FT-
HILL COUNTY-JUDITH BASIN COUNTY AND JUDITH GAP-LITTLE BELT AND
HIGHWOOD MOUNTAINS-NORTHERN BLAINE COUNTY-SNOWY AND JUDITH
MOUNTAINS-UPPER BLACKFOOT AND MACDONALD PASS-WESTERN AND CENTRAL
CHOUTEAU COUNTY.
HIGH WIND WARNING UNTIL 8 AM MST TUESDAY FOR EAST GLACIER PARK
REGION-EASTERN GLACIER, WESTERN TOOLE, AND CENTRAL PONDERA-
EASTERN TOOLE AND LIBERTY-NORTHERN HIGH PLAINS-SOUTHERN HIGH
PLAINS-SOUTHERN ROCKY MOUNTAIN FRONT.
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