220
FXUS65 KTFX 091127
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
527 AM MDT WED SEP 9 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- WARMER AND DRIER WEDNESDAY AND THURSDAY.
- NEXT WEATHER SYSTEM ARRIVES FRIDAY, BRINGING COOLER
TEMPERATURES ALONG WITH SOME PERIODS OF RAIN/MOUNTAIN SNOWFALL.
- ANOTHER WEATHER SYSTEM BRINGS EVEN COOLER TEMPERATURES AND
MORE WIDESPREAD PRECIPITATION TO MONTANA, WITH MORE CHANCES FOR
MOUNTAIN SNOWFALL.
DISCUSSION
/ISSUED 227 AM MDT WED SEP 9 2026/
- METEOROLOGICAL OVERVIEW:
IN THE WAKE OF A SERIES OF UPPER LEVEL SYSTEMS EARLIER THIS WEEK,
A WEAK RIDGE EMBEDDED IN NORTHWESTERLY FLOW WILL BRING A PERIOD
OF WARMER BUT BREEZY WEATHER TO NORTH CENTRAL MONTANA WEDNESDAY
AND THURSDAY. THIS PERIOD OF WARMER WEATHER WILL COME TO A QUICK
END ON FRIDAY AS A DECAYING UPPER LEVEL TROUGH MOVES THROUGH
SOUTHERN BRITISH COLUMBIA AND ALBERTA INTO MONTANA, WHICH WILL
BRING COOLER TEMPERATURES, ALONG WITH SOME SHOWERS OF RAIN AND
MOUNTAIN SNOWFALL AS IT PUSHES THROUGH. THE COOLER TEMPERATURES
WILL LINGER BEHIND THIS SYSTEM, WHICH WILL SET UP THE NEXT,
STRONGER SYSTEM TO PRODUCE WIDESPREAD PRECIPITATION WITH SNOW
EXPECTED ABOVE 7000 FEET, WHICH WOULD INCLUDE SOME OF THE HIGHER
MOUNTAIN PASSES. A BRIEF PERIOD OF WARMER AND DRIER WEATHER IS
EXPECTED LATE SUNDAY AND MONDAY BEFORE THE UNSETTLED PATTERN
RESUMES BY THE MIDDLE OF NEXT WEEK.
- FORECAST CONFIDENCE & SCENARIOS:
WINDS TODAY AND THURSDAY: WESTERLY, CROSS BARRIER FLOW WILL BRING
SOME GUSTY WINDS TO NORTH CENTRAL AND SOUTHWESTERN MONTANA
WEDNESDAY AND THURSDAY. WHILE WINDS ARE NOT EXPECTED TO BE STRONG
ENOUGH TO REACH HIGH WIND CRITERIA (58 MPH FOR MOST, 75 MPH ALONG
THE ROCKY MOUNTAIN FRONT), GUSTS TO 35-50 MPH WILL BE POSSIBLE
ACROSS THE AREA, ESPECIALLY ON THURSDAY WHEN WINDS WILL BE
STRONGEST.
MOUNTAIN SNOWFALL THIS WEEKEND: A STRONG UPPER LEVEL LOW WILL MOVE
INTO THE TREASURE STATE OVER THE WEEKEND, BRINGING WELL BELOW
AVERAGE TEMPERATURES ALONG WITH COPIOUS AMOUNTS OF MOISTURE. THE
COOLER TEMPERATURES WILL BRING SNOW LEVELS DOWN TO 7000 FEET ABOVE
SEA LEVEL, WHICH WILL RESULT IN WIDESPREAD MOUNTAIN SNOWFALL TO
AREAS ABOVE 7000 FEET. CURRENT FORECASTS KEEP SNOWFALL AMOUNTS
UNDER 6 INCHES AT THE MOMENT, BUT SOME OF THE HIGHEST TERRAIN
STILL HAVE AROUND A 10 PERCENT CHANCE OF SNOWFALL AMOUNTS OVER A
FOOT OVER THE WEEKEND. LUDWIG
AVIATION
09/12Z TAF PERIOD
HIGH CONFIDENCE IN VFR CONDITION ACROSS ALL TERMINALS THROUGH THE
ENTIRETY OF THE TAF PERIOD. A RIDGE OF HIGH PRESSURE WILL CONTINUE
TO PUSH EAST INTO MONTANA BRINGING WARMER TEMPERATURES AND BREEZY
CONDITIONS. THE TIMING IS CONSISTENT ACROSS ALL TERMINAL WITH
WINDS BEGINNING TO INCREASE AND TURN MORE SOUTHWESTERLY BETWEEN
16Z AND 19Z. CONDITIONS REMAIN CLEAR WITH WIDESPREAD CLEAR TO
MOSTLY CLEAR SKY AND HIGH CLOUD BASES. WINDS ARE OF GREATEST
ACROSS NORTH CENTRAL MONTANA SPECIFICALLY TERMINALS KCTB, KHLN,
KGTF, AND KHVR WHERE GUSTS OF 25-30KTS ARE EXPECTED FROM A
WEST/SOUTHWEST DIRECTION. REGION WIDE, GUSTS FROM THE SW UP TO
20KT ARE EXPECTED.
-JR
FOR KGTF: WINDS WILL BEGIN TO INCREASE 09/14Z OFFERING A BRIEF
PERIOD OF FAVORABLE WIND DIRECTION FROM THE SOUTHWEST. WINDS WILL
QUICKLY RAMP UP TO 10G20KT WITH A LOW (30%) CHANCE OF CROSSWINDS
EXCEEDING THE 15KT THRESHOLD. BY 09/17Z WINDS BECOME MORE
WESTERLY (240-260 DEGREES) WITH HIGH CONFIDENCE (>60%) OF GUSTS
WITH A CROSSWIND COMPONENT OF 15-18KT. WINDS BECOME NEARLY DUE
WEST (270 DEGREES) BY 09/20Z INCREASING THE CROSSWIND COMPONENT OF
SUSTAINED WINDS NEAR/ABOVE THE 15KT THRESHOLD. WINDS REMAIN
CONSISTENT TILL 10/02Z WHEN THEY BEGIN TO WANE/SHIFT SOUTHWEST.
-JR
PRELIMINARY POINT TEMPS/POPS
GTF 76 54 81 47 / 0 0 0 70
CTB 69 50 71 41 / 0 0 0 60
HLN 75 49 83 52 / 0 0 0 60
BZN 76 44 83 47 / 0 0 0 10
WYS 69 29 71 35 / 0 0 0 0
DLN 77 41 81 44 / 0 0 0 0
HVR 75 49 81 43 / 0 0 0 30
LWT 72 49 83 45 / 0 0 0 60
TFX WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH IN EFFECT FOR FIRE WEATHER ZONE 123 IN EFFECT
THURSDAY AFTERNOON.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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