776
FXUS65 KTFX 130529
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1129 PM MDT THU MAR 12 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- STRONG WINDS WILL DIMINISH FROM NORTH TO SOUTH ACROSS CENTRAL AND
SOUTHWEST MONTANA THROUGH THE REMAINDER OF THIS AFTERNOON AND
EVENING.
- GUSTY WINDS WILL CONTINUE TO CREATE SOME BLOWING AND DRIFTING SNOW
NEAR THE ROCKY MOUNTAIN FRONT THROUGH THE REST OF THIS
AFTERNOON BEFORE WINDS DECREASE TONIGHT.
- A FEW BRIEF BUT INTENSE SHOWERS WITH RAIN CHANGING TO SNOW WILL
AFFECT PORTIONS OF CENTRAL MONTANA THROUGH EARLY THIS EVENING.
- SNOW BECOMES MORE WIDESPREAD TONIGHT WITH PERIODS OF MODERATE
TO LOCALLY HEAVY SNOW EXPECTED ACROSS PORTIONS OF CENTRAL MT
FRIDAY INTO SATURDAY.
UPDATE
/ISSUED 727 PM MDT THU MAR 12 2026/
CURRENT FORECAST LOOKS TO REMAIN ON TRACK FOR THIS EVENING.
WIDESPREAD HIGH WINDS HAVE DECREASED EARLY THIS EVENING, WHICH
LEAD TO THE EXPIRATIONS OF THE HIGH WIND WARNINGS AT 6PM MDT.MODERATE
BANDS OF SNOW HAS DEVELOPED IN FERGUS AND JUDITH BASIN COUNTIES.
MODERATE AND HEAVY SNOW WILL CONTINUE TO DEVELOP ALONG ON THE
CENTRAL MT ISLAND RANGES AND JUDITH BASIN AND FERGUS COUNTIES THIS
EVENING, SINCE THAT IS WHERE THE BEST MID- LEVEL CONVERGENCE IS
AT THE MOMENT. THE SURFACE COLD FRONT IS CURRENTLY THE HELENA TO
WHITE SULPHUR SPRINGS CORRIDOR. THIS WILL SHIFT SLIGHTLY FARTHER
SOUTH TONIGHT. SNOW WILL SLOWLY FILL IN TONIGHT MOSTLY NORTH OF
I-90 THROUGH FRIDAY MORNING. PERIODS OF HEAVY SNOW WILL CONTINUE
ALONG THE CONTINENTAL DIVIDE TONIGHT. ANYWHERE SOUTH OF THE
FRONT/I-90 CAN STILL SEE LIGHT SNOW, BUT WEAKER FORCING LIMITS
SNOW ACCUMULATIONS OVERALL. -WILSON
DISCUSSION
/ISSUED 727 PM MDT THU MAR 12 2026/
- METEOROLOGICAL OVERVIEW:
A ROBUST PLUME OF PACIFIC MOISTURE EMBEDDED WITHIN A FAST WESTERLY
FLOW ALOFT WILL CONTINUE TO STREAM EAST ACROSS THE NORTHERN ROCKIES
AND MONTANA THROUGH EARLY THIS WEEKEND. THE CORE OF FASTEST WINDS
ALOFT HAS SHIFTED EAST OF THE AREA, AND THE STRONGEST WINDS HAVE
ABATED ACROSS AREAS NORTH OF GREAT FALLS TO LEWISTOWN, BUT STRONG
WINDS WILL CONTINUE TO IMPACT SOUTHERN PORTIONS OF CENTRAL MT AND
SOUTHWEST MT THROUGH THE REST OF THIS AFTERNOON. A PACIFIC FRONTAL
BOUNDARY HAS BECOME ALIGNED E-W WITH THE FLOW ALOFT ACROSS CENTRAL
MT, WHILE A CANADIAN AIRMASS CONTINUES TO GRADUALLY PUSH SOUTH
ACROSS N-CENTRAL MT AND IS EXPECTED TO REACH CENTRAL MT THIS
EVENING. BANDS OF SHOWERS IN THE VICINITY OF THESE FRONTS WILL
CONTINUE INTO THIS EVENING WITH ENOUGH COOLING FOR PRECIPITATION
TYPE TO BE PRIMARILY SNOW BY THIS EVENING AS LOWER LEVELS FURTHER
COOL ACROSS THE AREA. MEANWHILE OROGRAPHICALLY DRIVEN SNOW
CONTINUES ALONG THE CONTINENTAL DIVIDE AND SHOULD RE-INTENSIFY
LATER TONIGHT AS DEEPER PACIFIC MOISTURE ARRIVES. SNOW BECOMES
STEADIER AND MORE WIDESPREAD ACROSS CENTRAL AND NORTH-CENTRAL MT
AS WELL LATER TONIGHT THROUGH FRIDAY AS THE PACIFIC MOISTURE
OVERRUNS THE STALLED E-W FRONTAL BOUNDARY. SNOW INTENSITY LOOKS TO
BE LIGHT INITIALLY THROUGH EARLY FRIDAY BEFORE A SERIES OF
EMBEDDED SHORTWAVE DISTURBANCES BRING SOME ENHANCED FORCING FOR
PERIODS OF MODERATE SNOWFALL IN THE LATE FRIDAY THROUGH SATURDAY
PERIOD. SNOW WILL BEGIN TO DIMINISH SATURDAY NIGHT BUT MAY LINGER
INTO SUNDAY FOR PORTIONS OF NORTH-CENTRAL MT. THE COOLER AIRMASS
ACROSS NORTH-CENTRAL MT WILL CONTINUE THROUGH THE WEEKEND WITH
DAYTIME TEMPERATURES NEAR FREEZING AND OVERNIGHT TEMPERATURES AS
LOW AS THE SINGLE DIGITS ABOVE ZERO SATURDAY NIGHT. TEMPERATURES
ACROSS SOUTHWEST MT REMAIN NEAR TO ABOVE SEASONAL AVERAGES WITH
SOME COOLING THERE BRIEFLY SATURDAY NIGHT THROUGH SUNDAY. UPPER
LEVEL HIGH PRESSURE REMAINS ON TRACK TO BUILDS ACROSS THE INTERIOR
WESTERN US NEXT WEEK FOR A RETURN TO DRIER AND MUCH WARMER
CONDITIONS. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
BANDS OF SHOWERS ACROSS CENTRAL MT MAY BE LOCALLY INTENSE THROUGH
EARLY THIS EVENING. THIS INITIALLY MAY BEGIN AS RAIN OR GRAUPEL AT
LOWER ELEVATIONS, BUT A TRANSITION TO SNOW CAN LOCALLY REDUCE
VISIBILITY AND BRING SOME ACCUMULATION OF SLUSH ON SOME ROAD
SURFACES. WHILE ROAD SURFACES ARE WARM STILL THIS AFTERNOON, COOLING
TEMPERATURES TONIGHT AND THE DEVELOPMENT OF MORE WIDESPREAD AREAS
OF LIGHT SNOW COULD LEAD TO SOME SLICK ROAD SURFACES BY FRIDAY
MORNING.
CONFIDENCE IN SIGNIFICANT SNOW ACCUMULATION CONTINUES TO INCREASE
FOR THE TONIGHT THROUGH SATURDAY PERIOD ACROSS AREAS FROM THE
ROCKY MTN FRONT EAST ACROSS CENTRAL MT WHERE THERE IS A 60% OR
HIGHER PROBABILITY OF 6 INCH OR GREATER SNOWFALL AMOUNTS. THE BEST
CHANCE FOR SNOW ACCUMULATIONS OF A FOOT OR MORE EXISTS ACROSS THE
CENTRAL MT MOUNTAINS AND OVER THE ROCKY MTN FRONT, BUT EVEN LOWER
ELEVATIONS IN JUDITH BASIN AND FERGUS COUNTIES HAVE A 50-60% RISK
OF SNOWFALL AMOUNTS EXCEEDING 12 INCHES.
WINTER WEATHER IMPACTS LOOK TO BE GREATEST IN THE FRIDAY NIGHT
THROUGH SATURDAY PERIOD BUT THIS IS LONGER DURATION SNOWFALL EVENT
WITH SOME AREAS ALREADY DEALING WINTER/SNOWFALL IMPACTS THAT BEGAN
LAST NIGHT. HOENISCH
AVIATION
13/06Z TAF PERIOD
LIGHT SNOW WILL AFFECT MUCH OF NORTH CENTRAL MT THROUGH THE
PERIOD. SOME SHORT BREAKS ARE POSSIBLE, BUT OVERALL EXPECT NEAR
IFR CONDITIONS OR LOWER THROUGH THE PERIOD. FOR SOUTHWEST MT, IT
WILL NOT BE AS BAD. SOME RAIN/SNOW SHOWERS WILL PASS THROUGH THE
TERMINALS, BUT A LONG LASTING PRECIPITATION IS NOT EXPECTED AT
THIS TIME DURING THIS PERIOD OVER SW MT. MOUNTAINS/PASSES WILL BE
OBSCURED ACROSS THE CWA THROUGH THE PERIOD. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 27 34 25 31 / 70 100 90 100
CTB 20 29 18 24 / 70 80 70 100
HLN 33 44 31 42 / 80 100 100 100
BZN 34 55 36 49 / 50 70 60 100
WYS 31 45 30 42 / 40 60 60 100
DLN 37 56 38 49 / 20 30 40 80
HVR 22 35 20 29 / 40 50 60 100
LWT 23 32 21 34 / 100 100 100 100
TFX WATCHES/WARNINGS/ADVISORIES
WINTER STORM WARNING UNTIL 6 PM MDT SATURDAY FOR BIG BELT,
BRIDGER AND CASTLE MOUNTAINS-CASCADE COUNTY BELOW 5000FT-EAST
GLACIER PARK REGION-EASTERN PONDERA AND EASTERN TETON-ELKHORN
AND BOULDER MOUNTAINS-FERGUS COUNTY BELOW 4500FT-GATES OF THE
MOUNTAINS-HELENA VALLEY-JUDITH BASIN COUNTY AND JUDITH GAP-
LITTLE BELT AND HIGHWOOD MOUNTAINS-MEAGHER COUNTY VALLEYS-
NORTHERN HIGH PLAINS-NORTHWEST BEAVERHEAD COUNTY-SNOWY AND
JUDITH MOUNTAINS-SOUTHERN HIGH PLAINS-SOUTHERN ROCKY MOUNTAIN
FRONT-UPPER BLACKFOOT AND MACDONALD PASS.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT SATURDAY FOR BEARS PAW
MOUNTAINS AND SOUTHERN BLAINE-EASTERN GLACIER, WESTERN TOOLE,
AND CENTRAL PONDERA-EASTERN TOOLE AND LIBERTY-WESTERN AND
CENTRAL CHOUTEAU COUNTY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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