201
FXUS65 KTFX 280900
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
300 AM MDT MON SEP 28 2026
AVIATION SECTION UPDATED.
FORECAST SECTION UPDATED.
KEY MESSAGES
- ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE IN SOUTHWEST
MONTANA THROUGH THIS EVENING.
- WINDY AND DRY CONDITIONS ARE EXPECTED ON TUESDAY.
- COOL AND BREEZY CONDITIONS EXPECTED ON WEDNESDAY WITH A CHANCE
FOR RAIN ALONG THE NORTHERN ROCKIES AND ACROSS THE NORTHERN
PORTIONS OF NORTH CENTRAL MT.
UPDATE
UPDATED MORNING FORECAST TO ADD SOME THUNDER OVER PORTIONS OF
SOUTHWEST MT EARLY THIS MORNING. BRUSDA
DISCUSSION
/ISSUED 1203 AM MDT MON SEP 28 2026/
- METEOROLOGICAL OVERVIEW:
A WEAK SHORTWAVE WILL MOVE ACROSS THE REGION TODAY WITH WARMING
TEMPERATURES, BREEZY CONDITIONS ALONG THE ROCKY MOUNTAIN FRONT, AND
SCATTERED SHOWERS IN FAR SOUTHWESTERN MONTANA EXPECTED.
THE UPPER-LEVEL FLOW BECOMES MORE ZONAL TUESDAY INTO WEDNESDAY WITH
TWO ROUNDS OF STRONG WINDS EXPECTED TO MOVE OVER THE NORTHERN HALF
OF THE STATE. THE FIRST AND STRONGER WAVE OF WINDS IS EXPECTED ON
TUESDAY WITH WIDESPREAD GUSTS OVER 30 MPH ACROSS THE NORTHERN
PLAINS, GUSTS UP TO 50 MPH CLOSER TO THE ROCKY MOUNTAIN FRONT, AND
GUSTS UP TO 75 MPH POSSIBLE ALONG THE PORTION OF THE NORTHERN
ROCKIES HIGHLIGHTED IN THE HIGH WIND WATCH. THE SECOND WAVE OF WINDS
ON WEDNESDAY WILL BE MUCH WEAKER COMPARATIVELY WITH WIND GUSTS
GENERALLY STAYING IN THE 25 TO 35 MPH RANGE ACROSS MUCH OF CENTRAL
AND NORTH-CENTRAL MONTANA. THE MOISTURE PLUME ASSOCIATED WITH THIS
ZONAL FLOW REACHES THE CONTINENTAL DIVIDE IN THE EARLY MORNING HOURS
ON WEDNESDAY WITH A CHANCE FOR LIGHT RAIN ALONG THE NORTHERN ROCKIES
THROUGH THE MID-AFTERNOON HOURS. A FEW SHOWERS MAY DEVELOP ACROSS
NORTH-CENTRAL MONTANA, PARTICULARLY ALONG THE HI-LINE, BUT RAINFALL
AMOUNTS ARE EXPECTED TO REMAIN LIGHT.
WEAK UPPER-LEVEL RIDGING BRIEFLY BUILDS ON THURSDAY INTO FRIDAY
MORNING. THIS WILL ALLOW FOR A SLIGHT WARMUP ACROSS THE REGION
BEFORE THE MODELS START HINTING AT THE POTENTIAL FOR ANOTHER WEAK
SHORTWAVE TROUGH MOVING ACROSS THE REGION FRIDAY AFTERNOON INTO
SATURDAY.
- FORECAST CONFIDENCE & SCENARIOS:
THUNDERSTORMS IN SOUTHWEST MONTANA TODAY:
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON
ALONG THE MONTANA/IDAHO BORDER INTO CENTRAL MADISON AND GALLATIN
COUNTIES. PRECIPITATION AMOUNTS ARE NOT EXPECTED TO BE HIGH WITH
GENERALLY A COUPLE HUNDREDTHS OF AN INCH POSSIBLE. SEVERE WEATHER IS
NOT EXPECTED WITH ANY OF THESE THUNDERSTORMS WITH ONLY GUSTS IN THE
30-40 MPH RANGE EXPECTED.
STRONG WIND ON TUESDAY:
THE HIGHEST CONFIDENCE FOR HIGH WINDS REMAINS IN THE PORTION OF THE
NORTHERN ROCKIES AND GLACIER NATIONAL PARK HIGHLIGHTED IN THE HIGH
WIND WATCH. ACROSS THE REST OF THE NORTHERN PLAINS, THERE IS UPPER-
LEVEL SUPPORT FOR HIGH WINDS BUT NO GOOD MECHANISM TO BRING THOSE
WINDS TO THE SURFACE. THE ONE EXCEPTION MIGHT BE CUT BANK WHICH IS
DEPENDENT ON WHERE MOUNTAIN WAVE ACTIVITY SETS UP. BUT EVEN SO,
CONFIDENCE IS LESS THAN 50% ACROSS ALL ZONES WHICH MEANS THAT, FOR
NOW, NO EXPANSIONS WILL BE MADE TO THE HIGH WIND WATCH.
ELEVATED FIRE WEATHER CONCERNS ON TUESDAY:
WITH GUSTY WINDS, MINIMUM RH VALUES IN THE 20S, AND HIGHS IN THE 70S
ACROSS MUCH OF CENTRAL AND NORTH-CENTRAL MONTANA, THERE IS A CONCERN
FOR ELEVATED FIRE WEATHER CONDITIONS THROUGH THE AFTERNOON AND
EVENING HOURS. CONDITIONS ARE NOT CRITICAL ENOUGH TO PUT OUT ANY
FIRE WEATHER PRODUCTS BUT THEY ARE ELEVATED ENOUGH THAT ONGOING
FIRES OR NEW STARTS MAY BE DIFFICULT TO CONTAIN AT TIMES. FOLKS
SHOULD CONTINUE TO TAKE ALL PREVENTATIVE MEASURES TO REDUCE SPARKS.
-THOR
AVIATION
28/12Z TAF PERIOD.
MOSTLY CLOUDY SKIES ARE EXPECTED ACROSS THE CWA THROUGH THE
PERIOD. EXPECT SOME SHOWERS/THUNDERSTORMS THIS MORNING OVER
SOUTHWEST MT, WITH A CHANCE FOR THUNDERSTORMS THIS AFTERNOON
MOSTLY IN THE WEST YELLOWSTONE AREA. BREEZY WINDS THIS AFTERNOON
WILL DIMINISH THIS EVENING. MOUNTAINS/PASSES COULD BE OBSCURED AT
TIMES ACROSS THE CWA BY PRECIPITATION/CLOUDS. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 72 46 72 51 / 0 0 0 0
CTB 67 42 64 42 / 0 0 0 10
HLN 71 40 73 49 / 0 0 0 0
BZN 68 37 72 42 / 10 0 0 0
WYS 61 27 64 29 / 50 30 0 0
DLN 68 37 72 41 / 0 0 0 0
HVR 71 42 75 45 / 0 0 0 0
LWT 70 42 75 46 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING FOR
EAST GLACIER PARK REGION-NORTHERN HIGH PLAINS.
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