184
FXUS65 KTFX 012050
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
250 PM MDT TUE SEP 1 2026
KEY MESSAGES
- THUNDERSTORMS WITH SEVERE WIND GUSTS IN EXCESS OF 60 MPH
POSSIBLE ON WEDNESDAY, ESPECIALLY ACROSS THE PLAINS.
- WINDS WILL BE GUSTY ACROSS SOUTHWESTERN MONTANA WEDNESDAY AND
THURSDAY, BRINGING ELEVATED TO CRITICAL FIRE WEATHER
CONDITIONS.
- TEMPERATURES NEAR TO SLIGHTLY BELOW AVERAGE EXPECTED THIS
WEEK.
DISCUSSION
SOUTHWESTERLY FLOW ON THE WEST SIDE OF A QUICK MOVING UPPER LEVEL
RIDGE HAS BEGUN TO BRING INCREASING MOISTURE AND WARMTH TO
SOUTHWESTERN AND NORTH CENTRAL MONTANA. MOST LOWER ELEVATIONS
LOCALES HAVE REACHED THE UPPER 70S/LOW 80S, WHICH IS JUST SLIGHTLY
WARMER THAN OUR AVERAGE HIGHS FOR THIS TIME OF YEAR. IN ADDITION
TO THE WARMTH, A FEW SHOWERS AND THUNDERSTORMS HAVE BEGUN TO POP
UP ACROSS BEAVERHEAD COUNTY, AND THESE WILL GRADUALLY DRIFT TO THE
NORTH/NORTHEAST THROUGH THE REMAINDER OF THE EVENING. WHILE
SEVERE WIND GUSTS ARE NOT EXPECTED, A FEW GUSTS TO AROUND 50 MPH
WILL BE POSSIBLE WITH SOME OF THE STRONGER STORMS.
WINDS INCREASE ON WEDNESDAY AS A SHORTWAVE TROUGH EMBEDDED IN THE
FLOW MOVES OVERHEAD. WINDS WILL BE STRONGEST ACROSS SOUTHWESTERN
MONTANA, PARTICULARLY DURING THE LATE MORNING AND AFTERNOON,
ESPECIALLY IN THE NORTH/SOUTH ORIENTED VALLEYS. AS THIS SHORTWAVE
PROGRESSES FURTHER NORTH, SHOWERS AND THUNDERSTORMS WILL DEVELOP
AND MOVE NORTHWARD TOWARDS THE PLAINS. AS THESE STORMS REACH THE
PLAINS, THE COMBINATION OF STRONG WINDS ALOFT, ALONG WITH DRY MID
LEVELS AND A VERY DEEP AND WELL MIXED BOUNDARY LAYER, SOME OF THE
STORMS WILL BEGIN TO PRODUCE STRONG WIND GUSTS, SOME OF WHICH WILL
LIKELY BE OVER 60 MPH. WITH THIS IN MIND, SPC HAS UPGRADED OUR
MARGINAL RISK TO A SLIGHT RISK (1/5 TO 2/5) FOR TOMORROW
AFTERNOON.
WINDS WILL CONTINUE ACROSS SOUTHWESTERN MONTANA AS AN UPPER LEVEL
JET STREAK MOVES OVERHEAD, BUT WINDS ARE LIKELY NOT GOING TO BE
QUITE AS STRONG AS WEDNESDAY. THURSDAY SHOULD ALSO BRING GENERALLY
DRIER CONDITIONS TO THE TREASURE STATE EAST OF THE DIVIDE, ASIDE
FROM A FEW ISOLATED STRAY SHOWERS. LOOKING AHEAD TO THE WEEKEND,
AN UPPER LEVEL LOW SITUATED JUST OFF THE COAST OF OREGON AND
WASHINGTON WILL KEEP US ON THE UNSETTLED SIDE, AND MAY EVENTUALLY
ALLOW SOME MOISTURE FROM WHAT IS CURRENTLY TROPICAL STORM MARIE TO
WORK ITS WAY THROUGH THE WESTERN US AND INTO MONTANA EARLY NEXT
WEEK. LUDWIG
AVIATION
01/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL AT ALL TERMINALS DURING THIS TAF
PERIOD OUTSIDE OF DURING ANY THUNDERSTORMS. SHOWERS AND
THUNDERSTORMS WILL AFFECT THE KBZN, KEKS, KWYS, AND KHLN TERMINALS
BETWEEN 02/01Z AND 02/10Z. DURING ANY THUNDERSTORMS THERE WILL BE
GUSTY, ERRATIC WINDS, LIGHTNING, AND A BRIEF HEAVY DOWNPOUR. THE
HEAVY DOWNPOUR COULD BRIEFLY CAUSE MOUNTAIN OBSCURATION AND A
REDUCTION IN VISIBILITY TO MVFR-LEVELS. WINDS WILL BETWEEN TO
INCREASE ACROSS SOUTHWESTERN MONTANA BY THE END OF THIS TAF
PERIOD. DURING THIS TAF PERIOD SMOKE FROM WILDFIRES WILL REDUCE
SLANTWISE VISIBILITY ACROSS ALL TERMINALS. -IG
FOR KGTF: WINDS WILL BE LIGHT THROUGH AT LEAST 00Z WITH A ZERO
PERCENT CHANCE FOR EXCEEDING THE 15KT CROSSWIND THRESHOLD. BETWEEN
01Z AND 05Z THERE IS A 30% CHANCE FOR WIND GUSTS TO EXCEED THE 15
KT CROSSWIND THRESHOLD. BETWEEN 05Z AND 08Z THERE IS A 20 - 30%
CHANCE FOR A SHOWER AND/OR THUNDERSTORM TO REACH KGTF AND PRODUCE
AN OUTFLOW WIND WHICH WOULD EXCEED THE 15KT CROSSWIND THRESHOLD.
-IG
PRELIMINARY POINT TEMPS/POPS
GTF 57 85 50 78 / 0 40 10 0
CTB 52 80 46 69 / 0 80 50 0
HLN 52 82 48 78 / 40 40 10 0
BZN 50 81 48 78 / 30 10 0 0
WYS 38 66 34 66 / 70 20 0 0
DLN 46 77 44 75 / 50 20 0 0
HVR 54 90 50 82 / 0 30 40 0
LWT 55 85 49 80 / 0 10 10 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING FROM NOON TO 9 PM MDT WEDNESDAY FOR MADISON
RIVER VALLEY.
HIGH WIND WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY EVENING
FOR MADISON RIVER VALLEY.
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