700
FXUS65 KTFX 030017
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
617 PM MDT WED SEP 2 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- IT WILL BE WINDY ACROSS NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA THIS AFTERNOON THROUGH FRIDAY.
- SEVERE THUNDERSTORMS WILL CONTINUE THROUGH THIS EVENING WITH
WIND GUSTS IN EXCESS OF 60 MPH.
- IT WILL COOL OFF THROUGH THIS WEEKEND WITH SHOWERS AND
THUNDERSTORMS FRIDAY THROUGH SUNDAY.
DISCUSSION
/ISSUED 200 PM MDT WED SEP 2 2026/
- METEOROLOGICAL OVERVIEW:
THIS AFTERNOON THERE IS AN AN UPPER-LEVEL TROUGH MOVING OVER NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL ALLOW
TEMPERATURES TO COOL DOWN SLIGHTLY WITH SHOWERS AND THUNDERSTORMS
ACROSS THE AREA. DUE TO STRONG SOUTHERLY FLOW ALOFT AND STRONG LOW-
LEVEL WINDS IT WILL BE WINDY ACROSS NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA ON WEDNESDAY WITH THE STRONGEST WINDS ALONG THE
ROCKY MOUNTAIN FRONT AND IN NORTH-SOUTH ORIENTATED VALLEYS. ON
THURSDAY THE UPPER-LEVEL TROUGH REMAINS OVER NORTH-CENTRAL, CENTRAL,
AND SOUTHWESTERN MONTANA. THIS COMBINED WITH STRONG SOUTHERLY FLOW
ALOFT AND STRONG LOW-LEVEL WINDS WILL BRING ANOTHER DAY OF WINDY
CONDITIONS TO THE AREA. ON THURSDAY IT WILL BE MOSTLY DRY.
ON FRIDAY A CLOSED UPPER-LEVEL LOW IS OVER WASHINGTON AND OREGON
WITH SOUTHWEST FLOW OVER NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA. THIS WILL ALLOW TEMPERATURES TO BE AROUND SEASONAL
AVERAGES WITH ANOTHER DAY OF SHOWERS AND THUNDERSTORMS AND BREEZY
CONDITIONS. ON SATURDAY AND SUNDAY THE CLOSED UPPER-LEVEL LOW
REMAINS OVER WASHINGTON AND OREGON WITH SOUTHWEST FLOW OVER NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL BRING
ANOTHER DAY WITH ABOUT SEASONAL AVERAGES FOR TEMPERATURES AND
SHOWERS AND THUNDERSTORMS AROUND EACH DAY THIS WEEKEND. -IG
- FORECAST CONFIDENCE & SCENARIOS:
ON THURSDAY THERE IS A 40 - 60% CHANCE FOR WIND GUSTS OF 45 MPH OR
GREATER ACROSS SOUTHWESTERN MONTANA. ON THURSDAY THERE IS A 30 - 60%
CHANCE FOR WIND GUSTS OF 35 MPH OR GREATER ACROSS NORTH-CENTRAL
MONTANA. ON FRIDAY THERE IS A 40 - 80% CHANCE FOR WIND GUSTS OF 30
MPH OR GREATER ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA WITH THE GREATEST PROBABILITY IN SOUTHWESTERN MONTANA.
TODAY THE STORM PREDICTION CENTER (SPC) ISSUED A SLIGHT RISK (15%
CHANCE FOR WIND GUSTS OF 58 MPH OR GREATER WITHIN 25 MILES OF A
POINT) FOR SEVERE THUNDERSTORMS FOR MOST OF NORTH-CENTRAL MONTANA.
TODAY THE SPC ISSUED A MARGINAL RISK (5% CHANCE FOR WIND GUSTS OF
58 MPH OR GREATER WITHIN 25 MILES OF A POINT) ACROSS MOST OF THE
REST OF CENTRAL AND SOUTHWESTERN MONTANA. ON SATURDAY THERE IS A
15 - 30% CHANCE FOR THUNDERSTORMS ACROSS CENTRAL AND SOUTHWESTERN
MONTANA. ON SUNDAY THERE IS A 15 - 30% CHANCE FOR THUNDERSTORMS
ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. -IG
FIRE WEATHER: MEDIUM CONFIDENCE (50%) IN CRITICAL CONDITIONS ON
TODAY AND THURSDAY. WINDS ARE THE HIGHEST SOURCE OF CONFIDENCE,
HUMIDITY IS OUR LOWEST WITH VALUES BORDERLINE. HOWEVER, DEEP
MIXING ADVERTISED BY THE MODELS DOES SUPPORT VALUES APPROACHING
CRITICAL VALUES.
EXTENDED REGIME: LOW CONFIDENCE (30%) IN THE OVERALL CHANGES IN THE
UPPER-LEVEL PATTERN. CUT OFF LOWS ARE NOTORIOUSLY DIFFICULT TO PIN
POINT IN THE LONG RANGE AS ARE THE RESULTING IMPACTS. -JR
AVIATION
03/00Z TAF PERIOD
TERMINAL KHVR HAS A LOW PROBABILITY OF -TSRA
THROUGH 02Z AS OUT PRIMARY SYSTEM EXITS NORTHEAST. HIGH CONFIDENCE
IN VFR CONDITIONS ACROSS ALL TERMINALS AS REMNANT THUNDERSTORMS
CONTINUE TO PROGRESS NORTHEAST OUT OF THE REGION. SURFACE WINDS
WILL LARGELY CALM DOWN THROUGH THE NIGHT, WITH SOUTHWEST TERMINAL
KWYS, KEKS, AND KBZN REMAINING BREEZY ABOVE 10KTS. WINDS RAMP BACK
UP ACROSS ALL TERMINALS MOVING INTO THURSDAY AFTERNOON AS OUR
SHORTWAVE PROGRESSES ACROSS MONTANA. ISOLATED LIGHT SHOWERS ACROSS
SOUTHWEST MONTANA THURSDAY MORNING. LOW CONFIDENCE IN THESE
ACROSS TERMINAL KEKS, WITH HIGHER CONFIDENCE IN KWYS. IF THESE
STORMS WERE TO IMPACT THE TERMINAL, EXPECTED LOWERED CEILINGS AND
ERRATIC GUSTY WINDS.
FOR KGTF: GUSTY WINDS WILL CONTINUE THROUGH AT LEAST 03/04Z
BEFORE SLOWLY TAPERING OFF AS THE NIGHT CONTINUES. THE THREAT FOR
CROSSWINDS WILL BE LOW BUT THE HEADWINDS MAY BE ABOVE 15KTS
THROUGH AT LEAST 03/05Z. WINDS WILL AGAIN RAMP UP 03/17Z. FOR A
BRIEF PERIOD BETWEEN 17Z AND 20Z PROBABILITY OF CROSS WINDS
MEETING THE 15KT THRESHOLD IS 20% BEFORE WINDS SOLIDLY SHIFT FROM
THE SOUTHWEST WITH LOW PROBABILITY OF CROSS WINDS EXCEEDING THE
15KT THRESHOLD FOR THE REMAINDER OF THE TAF PERIOD.
-JR
PRELIMINARY POINT TEMPS/POPS
GTF 84 50 76 49 / 60 10 0 10
CTB 79 46 66 45 / 90 50 0 30
HLN 81 46 75 47 / 80 10 0 10
BZN 80 47 76 45 / 20 0 0 0
WYS 65 33 64 36 / 10 0 0 0
DLN 77 42 72 41 / 30 10 0 10
HVR 90 50 80 51 / 50 50 0 0
LWT 85 49 77 52 / 40 20 0 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR MADISON RIVER
VALLEY.
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