528
FXUS65 KTFX 051752
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1152 AM MDT SAT SEP 5 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS WILL PUSH THROUGH MONTANA ON SUNDAY,
SOME OF WHICH MAY BRING SOME GUSTY WINDS.
- WIDESPREAD SOAKING RAINFALL EXPECTED SUNDAY THROUGH TUESDAY, WITH
SOME AREAS ON THE HI-LINE HAVING A 40-60 PERCENT CHANCE OF SEEING
2 INCHES OF RAINFALL.
- TEMPERATURES START NEXT WEEK BELOW AVERAGE, BEFORE RETURNING
TO NEAR AVERAGE FOR THE SECOND HALF OF THE WEEK.
UPDATE
CURRENT FORECAST IS ON TRACK, NO UPDATES PLANNED FOR THIS MORNING.
LIGHT RAIN SHOWERS CONTINUE TO MOVE NORTHWARD THROUGH MOSTLY THE
NORTHERN PORTIONS OF THE CWA THIS MORNING. RAINFALL IS LIGHT,
GENERALLY LESS THAN 0.05 INCHES. TEMPERATURES WILL BE A BIT COOLER
TODAY. EVEN COOLER TEMPERATURES FOR SUN/MON, ALONG WITH A BETTER
CHANCE FOR MORE WIDESPREAD RAIN AND THUNDERSTORMS. BRUSDA
DISCUSSION
/ISSUED 200 AM MDT SAT SEP 5 2026/
- METEOROLOGICAL OVERVIEW:
A DEEP AND SLOW MOVING UPPER LEVEL TROUGH OVER THE EASTERN
PACIFIC/WESTERN US WILL SLOWLY MOVE EASTWARD OVER THE COMING DAYS.
AS IT MOVES EASTWARD, EXPECT RAIN ALONG THE CONTINENTAL DIVIDE
TODAY TO SLOWLY SHIFT EASTWARD AND EXPAND, WITH MORE WIDESPREAD
SHOWERS AND THUNDERSTORMS SUNDAY, MONDAY, AND EARLY TUESDAY BEFORE
THIS SYSTEM DEPARTS LATE TUESDAY MORNING AND WEDNESDAY. BEHIND
THIS SYSTEM, DRIER WEATHER IS EXPECTED WEDNESDAY AND THURSDAY AS
WEAK UPPER LEVEL RIDGING TRANSITS THE AREA, WHICH WILL ALSO BRING
TEMPERATURES BACK CLOSER TO AVERAGE AFTER A COOL START TO THE
WEEK. HOWEVER, MORE UNSETTLED WEATHER LOOKS LIKELY TO CLOSE OUT
THE WEEK AS YET ANOTHER UPPER LEVEL TROUGH PUSHES INTO THE WESTERN
US.
- FORECAST CONFIDENCE & SCENARIOS:
THUNDERSTORMS SUNDAY: RECENT HI RES MODEL GUIDANCE HAS BEGUN TO
HINT AT THE POSSIBILITY OF A ROUND OF THUNDERSTORMS ON SUNDAY
CAPABLE OF PRODUCING SOME STRONG TO SEVERE WIND GUSTS. WHILE IT
DOES NOT CURRENTLY LOOK QUITE AS DAMAGING AS WEDNESDAY’S EVENT
WAS, THERE ARE STILL A FEW THINGS TO NOTE ABOUT THE SEVERE THREAT.
MODEL SOUNDINGS AND HODOGRAPHS (TEMPERATURE/HUMIDITY PROFILES AND
WIND PROFILES, RESPECTIVELY) SHOW QUITE A BIT OF INSTABILITY IN
THE MID/UPPER LEVELS, ALONG WITH AMPLE SHEAR TO HELP STORMS FORM
AND THEN ORGANIZE AND STRENGTHEN AS THEY RACE NORTHEASTWARD THANKS
TO RELATIVELY STRONG WINDS (IN EXCESS OF 50 KNOTS/60 MPH). GIVEN
THE WET ENVIRONMENT, IT WILL BE DIFFICULT FOR ANY LARGER HAIL TO
REACH THE SURFACE, BUT SOME SMALLER HAIL MAY STILL REACH THE
SURFACE. WINDS ARE A BIT TRICKY AS WELL, AS WHILE THERE IS BOTH
SUFFICIENT DRY AIR NEAR THE SURFACE AND WINDS ALOFT TO RESULT IN
SOME STRONG WIND GUSTS, THERE ARE ALSO HINTS OF SOME CAPPING WHICH
MAY LIMIT TRANSPORT OF THE WINDS TO THE SURFACE. GIVEN THE
UNCERTAINTY, SPC HAS PLACED MUCH OF NORTH CENTRAL AND CENTRAL
MONTANA ON SUNDAY, WHICH SEEMS REASONABLE AT THE MOMENT GIVEN THE
UNCERTAINTY.
RAINFALL THROUGH TUESDAY: MODELS REMAIN FAIRLY CONSISTENT ON A
PERIOD OF WIDESPREAD SOAKING RAINFALL ACROSS NORTH CENTRAL AND
SOUTHWESTERN MONTANA THROUGH TUESDAY. MOST MODELS ALSO REMAIN
CONSISTENT IN PLACING THE HEAVIEST PRECIPITATION NORTH OF A HELENA
TO GREAT FALLS TO LEWISTOWN LINE, WHERE AMOUNTS OF 1TO 2 INCHES
APPEAR LIKELY. HOWEVER, THERE REMAINS SOME POSSIBILITY THAT SOME
AREAS COULD SEE MORE SIGNIFICANT RAINFALL TOTALS (IN EXCESS OF 3 OR
4 INCHES), WHICH COULD RESULT IN SOME INCREASES TO RIVERS AND
STREAMS. WIDESPREAD FLOODING REMAINS UNLIKELY, THOUGH SOME AREAS
COULD SEE SOME PONDING OF POOR DRAINAGE AREAS. LUDWIG
AVIATION
05/18Z TAF PERIOD
THE MAIN CONCERN WILL BE LOW CEILINGS, ALONG WITH
SHOWERS/THUNDERSTORMS THIS AFTERNOON THROUGH TONIGHT. MOST OF THE
PRECIPITATION WILL BE OVER THE WESTERN PORTIONS OF THE CWA. ON
SUNDAY, EXPECT LOWER CEILINGS, WITH MORE A STEADY RAIN DEVELOPING
OVER THE WESTERN PORTIONS OF NORTH CENTRAL MT. THE STEADY RAIN
WILL START TO BE MORE OF AN IMPACT OVER THE EASTERN PORTIONS OF
NORTH CENTRAL MT BY SUNDAY NIGHT. MOUNTAINS/PASSES WILL BE
OBSCURED AT TIMES BY CLOUDS/PRECIP, ESPECIALLY LATER TONIGHT AND
INTO SUNDAY.
FOR KGTF: THE MAIN CONCERN FOR STRONGER WINDS IN GREAT FALLS WILL
BE FROM ABOUT 20Z TODAY THRU 03Z THIS EVENING WITH PASSING
THUNDERSTORMS EXPECTED WEST OF THE GREAT FALLS AIRPORT. THESE
PASSING THUNDERSTORMS COULD PRODUCE OUTFLOW WIND GUSTS THAT COULD
AFFECT THE GREAT FALLS AIRPORT. AT THIS TIME, MOST WIND GUSTS
SHOULD REMAIN LESS THAN 20 KNOTS, BUT WIND DIRECTIONS COULD BE
ERRATIC WITH THE GUSTS. LOWER CEILINGS DEVELOP TONIGHT AND
CONTINUE INTO SUNDAY, WITH A BETTER CHANCE FOR A MORE WIDESPREAD
LIGHT RAIN BY SUNDAY NIGHT. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 73 50 73 51 / 10 30 10 90
CTB 65 46 63 46 / 70 90 80 80
HLN 76 49 77 52 / 10 20 10 70
BZN 79 46 82 49 / 0 0 0 60
WYS 72 38 75 40 / 0 0 0 80
DLN 78 43 80 46 / 0 0 0 70
HVR 79 51 77 51 / 10 10 50 90
LWT 76 49 79 50 / 0 0 20 90
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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