393
FXUS65 KTFX 292354
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
554 PM MDT SAT AUG 29 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS OVERNIGHT, SOME OF WHICH COULD
PRODUCE GUSTY WINDS AND BRIEF DOWNPOURS.
- COOL AND BREEZY SUNDAY WITH HIGHS IN THE 60S FOR MOST LOWER
ELEVATION LOCATIONS, WITH 50S IN THE MOUNTAINS.
- DRIER MONDAY, BUT SHOWERS AND THUNDERSTORMS RETURN BY TUESDAY.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A DEEP UPPER LEVEL LOW MOVING INTO THE PACIFIC NORTHWEST WILL
CONTINUE TO FUNNEL MOISTURE INTO NORTH CENTRAL AND SOUTHWESTERN
MONTANA TODAY ON SOUTHWESTERLY FLOW ALOFT. EARLY AFTERNOON RADAR
HAS SHOWN NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS
SOUTHWESTERN MONTANA, WITH A FEW ALSO DEVELOPING OVER THE ROCKY
MOUNTAIN FRONT AND LITTLE BELT AND SNOWY MOUNTAINS. WHILE SEVERE
WIND GUSTS ARE NOT EXPECTED TODAY, I CAN’T ENTIRELY RULE OUT A
STRONGER STORM PRODUCING A ROGUE GUST OVER 50 MPH OR SO, ALONG
WITH SOME HEAVIER DOWNPOURS, ESPECIALLY IF THEY CAN GET A BIT MORE
ORGANIZED. THE MOST LIKELY AREA FOR THE WINDS TO GET GUSTY WILL
BE ACROSS THE PLAINS, WHERE CLOUDS WILL HOLD OFF JUST LONG ENOUGH
TO ALLOW FOR SOME BETTER THERMAL MIXING AND DEEPENING OF THE MIXED
LAYER. WHILE STORMS SHOULD WEAKEN AFTER SUNSET, SHOWERS WITH A
FEW RUMBLES OF THUNDER WILL REMAIN POSSIBLE THROUGH MUCH OF THE
OVERNIGHT THANKS TO PERSISTENTLY STRONG UPPER LEVEL DYNAMICS.
AS WE HEAD INTO THE DAY ON SUNDAY, WINDS SHIFT TO THE WEST AS THE
UPPER LEVEL LOW MOVES OVERHEAD, WHICH WILL BRING A SURFACE COLD
FRONT ALONG WITH IT LATE TONIGHT/EARLY SUNDAY MORNING. BEHIND THIS
FRONT, EXPECT TEMPERATURES TO BE NOTABLY COOLER TOMORROW, WITH
MOST LOCATIONS ONLY RISING INTO THE 60S, ALONG WITH A BREEZY
WESTERLY WIND WITH MOST AREAS ON THE PLAINS GUSTING TO 25-40 MPH
AND 15-30 MPH ACROSS THE SOUTHWEST.
WHILE IT WILL REMAIN BREEZY ON THE PLAINS/ROCKY MOUNTAIN FRONT
OVERNIGHT SUNDAY NIGHT INTO MONDAY MORNING, EXPECT MORE PLEASANT
CONDITIONS TO ARRIVE FOR THE DAYTIME ON MONDAY AS UPPER LEVEL
RIDGING BEGINS TO BUILD BACK ACROSS THE NORTHERN ROCKIES. WHILE
THIS RIDGE WILL KEEP US DRY ON MONDAY, IT WILL QUICKLY MOVE EAST
AS A STRONG TROUGH MOVES TOWARDS THE WEST COAST. AS THIS TROUGH
APPROACHES, SOUTHWESTERLY FLOW ALOFT WILL BRING A SURGE OF
MOISTURE INTO THE AREA, RESULTING IN AFTERNOON THUNDERSTORM
DEVELOPMENT TUESDAY AND WEDNESDAY. A STRONGER UPPER LEVEL LOW WILL
LIKELY MOVE TOWARDS THE PACIFIC NORTHWEST LATE NEXT WEEK, WHICH
WOULD ALLOW FOR ADDITIONAL SHOWERS AND THUNDERSTORMS THURSDAY AND
FRIDAY.
- FORECAST CONFIDENCE & SCENARIOS:
RAIN TODAY: SOME OF THE CONVECTION ALLOWING MODELS HAVE WANTED TO
HAVE SOME POCKETS OF HEAVIER RAINFALL (UP TO AN INCH) FROM SOME
OF THE SHOWERS AND THUNDERSTORMS TODAY. WHILE OUR SOILS SHOULD BE
ABLE TO READILY ABSORB THESE HEAVIER RAINFALL AMOUNTS, REPEATED
HEAVY RAINFALL MAY RESULT IN SOME PONDING OF WATER IN POOR
DRAINAGE AREAS.
WINDS SUNDAY: BEHIND THE COLD FRONT MENTIONED ABOVE, EXPECT GUSTY
WINDS TO AFFECT MOST OF NORTH CENTRAL AND SOUTHWESTERN MONTANA ON
SUNDAY. WHILE COOLER TEMPERATURES, RECENT RAINFALL, AND RH VALUES
GENERALLY STAYING ABOVE 25-30% WILL PREVENT CRITICAL FIRE WEATHER
CONDITIONS, WIND GUSTS WILL STILL BE NOTABLE FOR LATE AUGUST.
EXPECT AN 80-90% CHANCE OF SEEING WIND GUSTS OVER 40 MPH ALONG THE
ROCKY MOUNTAIN FRONT, NORTHERN SLOPES OF THE LITTLE BELT AND
SNOWY MOUNTAINS, AND AROUND THE BEARS PAW MOUNTAINS, AND A 30-60%
CHANCE OF SEEING GUSTS OVER 48 MPH. WHILE NOT IMPOSSIBLE, THE RISK
OF SEEING HIGH WIND GUSTS (OVER 58 MPH) APPEARS TO BE LOW,
GENERALLY UNDER 10-20%, I CAN NOT COMPLETELY RULE OUT AN ISOLATED
INSTANCE OF HIGH WINDS TOMORROW. LUDWIG
AVIATION
30/00Z TAF PERIOD
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT THE CWA THROUGH
THE OVERNIGHT HOURS. SOME STORMS WILL PRODUCE GUSTY WINDS. EXPECT
AN AREA OF STEADY RAIN TO DEVELOP OVER SOUTHWEST MT AFTER 8Z SUN
AND THEN MOVE NORTHEASTWARD UP INTO CENTRAL MT. OVERALL, MUCH OF
THE PRECIPITATION WILL EXIT THE CWA BY 18Z SUN. WINDY CONDITIONS,
WITH CLEARING SKIES MOVE IN FROM THE WEST STARTING SUNDAY
AFTERNOON. MOUNTAINS/PASSES WILL BE OBSCURED THROUGH AT LEAST 18Z
SUN.
FOR KGTF: IT WILL BECOME WINDY ON SUNDAY AFTERNOON. SUSTAINED
WINDS OVER 20 KNOTS WITH GUSTS IN THE MID 30 KNOTS WILL BE COMMON
THROUGH THE AFTERNOON HOURS. WINDS SHOULD BEGIN TO DIMINISH AFTER
01Z MONDAY.
PRELIMINARY POINT TEMPS/POPS
GTF 50 65 45 77 / 90 50 0 0
CTB 46 61 44 74 / 60 10 0 0
HLN 46 67 43 78 / 80 20 0 0
BZN 47 67 39 78 / 70 70 0 0
WYS 36 62 30 71 / 70 70 0 0
DLN 44 69 38 79 / 70 30 0 0
HVR 51 68 47 77 / 80 60 10 0
LWT 47 64 42 77 / 80 90 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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