993
FXUS65 KTFX 240050
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
650 PM MDT FRI OCT 23 2026
KEY MESSAGES
- WET SNOW AND WIND IMPACTS THROUGH EARLY THIS EVENING WILL
DIMINISH OVERNIGHT.
- GREATEST POTENTIAL FOR MODERATE SNOWFALL RATES AND WINDY CONDITIONS
THROUGH EARLY THIS EVENING ACROSS AREAS NEAR THE CENTRAL
MONTANA MOUNTAINS
- STRONG WINDS ACROSS PORTIONS OF NORTH-CENTRAL MT DIMINISH
FROM WEST TO EAST TONIGHT.
- DRIER BUT CONTINUED COOLER THAN AVERAGE CONDITIONS ARE
EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK.
UPDATE
THE CORE OF THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE COLD
FRONT AND ASSOCIATED WINTER WEATHER IS BEGINNING TO SHIFT TOWARD
EASTERN MT THIS EVENING. IN THE MEANTIME, A BAND OF SNOW CONTINUES
TO SHIFT EASTWARD, ACROSS NORTH-CENTRAL THROUGH SW MT, DIMINISHING
OR EXITING EAST OF THE AREA BY EARLY SATURDAY MORNING. SNOWFALL
RATES IN EXCESS OF A HALF INCH PER HOUR WILL CONTINUE WITH THIS
BAND AS IT MOVES EASTWARD. AREAS NEAR PASS LEVEL CONTINUE TO BE
THE MOST IMPACTED FROM THIS EVENT, BUT IMPACTS ARE FORECAST TO
INCREASE THIS EVENING AT LOWER ELEVATIONS WITH THE LOSS OF DAYTIME
HEATING. LEWISTOWN STILL LOOKS TO SEE GREATEST ACCUMULATIONS AT
LOWER ELEVATIONS, WITH ISOLATED AMOUNTS APPROACHING 6 INCHES IN
THE FOOTHILLS TO THE SOUTH AND EAST OF TOWN.
STRONG WIND GUSTS CONTINUE IN AREAS LEE OF TERRAIN IN FERGUS
COUNTY. THE HIGH WIND WARNING IS IN EFFECT UNTIL 9 PM FOR THIS
AREA, BUT IT WILL BE MONITORED FOR THE POTENTIAL TO BE EXTENDED A
BIT LONGER.
OTHERWISE THE CONCERN HEADING INTO SATURDAY WILL BE FOR FOG IN
AREAS THAT CLEAR OUT AND HAVE SUFFICIENTLY WEAK WINDS. AT THIS
POINT THE SW MT VALLEYS ARE MOST FAVORED FOR THE FOG. -AM
DISCUSSION
/ISSUED 527 PM MDT FRI OCT 23 2026/
- METEOROLOGICAL OVERVIEW:
A FAIRLY VIGOROUS MID LEVEL WAVE ACCOMPANIED BY ANOMALOUS MOISTURE
CONTINUES TO LIFT NORTH ACROSS CENTRAL MT THIS AFTERNOON AHEAD OF
AN UPPER LEVEL TROUGH TRACKING EAST ACROSS THE ROCKIES. THIS WILL
CONTINUE TO SUPPORT WIDESPREAD PRECIPITATION ACROSS MUCH OF THE
AREA INTO EARLY THIS EVENING BEFORE DRYING BEHIND THE EASTWARD
MOVING TROUGH BRINGS AN END TO PRECIPITATION FROM WEST TO EAST
LATE THIS EVENING/OVERNIGHT.
POTENTIAL FOR EMBEDDED ISOLATED THUNDERSTORMS AND BRIEF MODERATE-
HEAVY PRECIPITATION RATES WILL DECREASE LATE THIS AFTERNOON AS THE
STRONGEST LIFT MOVES OUT OF THE AREA AND STABILITY INCREASES. THE
RISK FOR IMPACTS FROM LOCALIZED INTENSE PRECIPITATION HAS ALSO
DECREASED AS SNOW LEVELS CONTINUE TO LOWER, LEADING TO REDUCED
RUNOFF.
SURGE OF COLDER AIR FROM CANADA WILL CONTINUE TO SPREAD EAST ACROSS
REMAINING EASTERN PORTIONS OF NORTH-CENTRAL MT AND SOUTH THROUGH THE
VALLEYS OF SW MT THROUGH THE REST OF THIS AFTERNOON AND EVENING,
BRINGING A TRANSITION TO WET SNOW TO EVEN THE LOWEST ELEVATIONS
BEFORE PRECIPITATION ENDS LATER THIS EVENING. STRONGEST NORTH/NORTHWEST
WINDS WITH THE INITIAL SURGE OF THE COOLER AIRMASS ACROSS WESTERN
PORTIONS OF NORT-CENTRAL MT WILL BEGIN TO GRADUALLY DECREASE LATE
THIS AFTERNOON, WHILE EASTERN PORTIONS OF NORTH-CENTRAL MT WILL
HAVE WINDS PEAK LATE THIS AFTERNOON BUT NOT LIKELY TO NOTICEABLY
DIMINISH UNTIL LATER TONIGHT.
MODERATE TO HEAVY SNOWFALL RATES ARE MOST LIKELY TO OCCUR LATE THIS
AFTERNOON WITH LINGERING ANOMALOUS MOISTURE STILL IN PLACE
AHEAD OF THE UPPER TROUGH AXIS, WITH A TRANSITION TO MORE
OROGRAPHIC/UP-SLOPE FORCED SNOWFALL OCCURRING THIS EVENING BEFORE
PRECIPITATION ENDS. HIGH RESOLUTION MODEL ENSEMBLES HAVE THE
HIGHEST PROBABILITIES(80% OR BETTER) FOR 1"/HR RATED ACROSS THE
LITTLE BELT AND N-CENTRAL MT ISLAND RANGES AND NEARBY FOOTHILLS
BETWEEN 4PM AND 7PM WITH A 20-40% PROBABILITY FOR ADJACENT
PORTIONS OF FERGUS AND JUDITH BASIN COUNTIES INCLUDING THE JUDITH
GAP AND LEWISTOWN AREAS.
A DRIER WESTERLY FLOW MOVES ACROSS THE NORTHERN ROCKIES SATURDAY
BEHIND THE DEPARTING SYSTEM WITH A BROAD AREA OF UPPER LEVEL
TROUGHING LINGERING ACROSS WESTERN CANADA AND EXTENDING TO
OFFSHORE OF THE US WEST COAST. THIS HOLDS A COOLER THAN AVERAGE
AIRMASS ACROSS THE REGION INTO EARLY NEXT WEEK WITH SURFACE HIGH
PRESSURE CENTERED OVER THE CANADIAN PRAIRIES AND GENERALLY DRY
CONDITIONS PREVAILING THROUGH MONDAY. MEDIUM RANGE MODELS ARE
CONVERGING ON THE IDEA OF A LOBE OF ENERGY MOVING OUT OF THE
LARGER SCALE TROUGH ACROSS THE NW US AROUND TUESDAY. THIS WOULD BE
A COLDER SYSTEM WITH LOWER SNOW LEVELS TO START, BUT WOULD LIKELY
NOT HAVE AS MUCH DEEP MOISTURE AVAILABLE AS THE CURRENT SYSTEM
AND THERE IS STILL CONSIDERABLE UNCERTAINTY THIS THIS TIME WITH
MORE SPECIFIC DETAILS. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
MAIN CONCERNS FOR WINTER WEATHER IMPACTS THROUGH THE REST OF THIS
AFTERNOON AND EVENING ARE IN AREAS THAT SEE THE HEAVIER SNOWFALL
RATES IN CONJUNCTION WITH WINDY CONDITIONS. THIS IS MOST LIKELY
ACROSS AREAS NEAR THE LITTLE BELTS/SNOWIES AND ADJACENT PORTIONS OF
JUDITH BASIN, FERGUS AND SOUTHEASTERN CASCADE COUNTIES. HOENISCH
AVIATION
24/00Z TAF PERIOD
SNOW WILL CONTINUE FOR THE NEXT FEW HOURS ENDING BY 24/06Z AT ALL OF
THE TERMINALS EXCEPT FOR THE KCTB AND KWYS TERMINALS. AT THE KGTF
AND KLWT TERMINALS SNOW WILL REDUCE VISIBILITY TO A QUARTER MILE FOR
THE NEXT COUPLE OF HOURS. AT THE KBZN, KEKS, AND KHVR TERMINALS SNOW
WILL REDUCE VISIBILITY TO IFR-LEVELS FOR THE NEXT COUPLE OF HOURS.
BY AT LEAST 24/09Z CLOUDS WILL RAISE AND VFR CONDITIONS WILL PREVAIL
AT ALL TERMINALS THROUGH THE END OF THE TAF PERIOD. AT THE KBZN,
KHLN, AND KGTF TERMINALS BETWEEN 24/09Z AND 24/14Z THERE IS A LOW
CHANCE FOR FOG TO FORM. BETWEEN NOW AND 24/06Z THERE WILL BE
ISOLATED INSTANCES OF LOW-LEVEL WIND SHEAR ACROSS NORTH-CENTRAL
MONTANA. THERE WILL BE MOUNTAIN OBSCURATION ACROSS NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA THROUGH AT LEAST 24/06Z.
BETWEEN NOW AND 24/09Z THERE WILL BE GUSTY WINDS AT THE KCTB,
KGTF, KHVR, AND KLWT TERMINALS. -IG
PRELIMINARY POINT TEMPS/POPS
GTF 25 43 25 38 / 100 0 0 0
CTB 21 42 23 39 / 0 0 0 0
HLN 21 44 24 42 / 80 0 0 0
BZN 21 41 20 43 / 100 0 0 0
WYS 15 46 15 50 / 90 0 0 0
DLN 25 44 24 46 / 100 0 0 0
HVR 23 44 22 44 / 100 0 0 0
LWT 21 40 21 39 / 100 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 3 AM MDT SATURDAY FOR BEARS PAW
MOUNTAINS AND SOUTHERN BLAINE-FERGUS COUNTY BELOW 4500FT-JUDITH
BASIN COUNTY AND JUDITH GAP-SNOWY AND JUDITH MOUNTAINS.
WINTER WEATHER ADVISORY UNTIL 9 PM MDT THIS EVENING FOR CASCADE
COUNTY BELOW 5000FT-SOUTHERN HIGH PLAINS-SOUTHERN ROCKY MOUNTAIN
FRONT.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR FERGUS COUNTY
BELOW 4500FT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR BIG BELT,
BRIDGER AND CASTLE MOUNTAINS-ELKHORN AND BOULDER MOUNTAINS-
GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS-
LITTLE BELT AND HIGHWOOD MOUNTAINS-NORTHWEST BEAVERHEAD COUNTY-
RUBY MOUNTAINS AND SOUTHERN BEAVERHEAD MOUNTAINS-UPPER BLACKFOOT
AND MACDONALD PASS.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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