419
FXUS65 KTFX 052044
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
244 PM MDT SAT SEP 5 2026
KEY MESSAGES
- SHOWERS AND THUNDERSTORMS TONIGHT AND SUNDAY, BECOME A MORE
WIDESPREAD RAINFALL SUNDAY NIGHT INTO MONDAY.
- AN ISOLATED SEVERE STORM POSSIBLE SUNDAY.
- COOL TEMPERATURES TO BEGIN THE WEEK, WITH SOME WARMER AFTERNOON
TEMPERATURES FOR A FEW DAYS MID WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A SLOW MOVING UPPER LEVEL LOW WILL REMAIN TO OUR WEST THROUGH
SUNDAY, BEFORE SLOWLY MOVING EASTWARD SUNDAY NIGHT INTO MONDAY.
EXPECT WAVES OF SHOWERS/THUNDERSTORMS TO MOVE THROUGH THE CWA FROM
NOW THROUGH SUNDAY AFTERNOON. THERE IS THE POTENTIAL THAT A FEW
STORMS COULD BECOME SEVERE ON SUNDAY, THUS MUCH OF THE CWA IS IN A
MARGINAL RISK FOR SEVERE STORMS. AS THE UPPER LEVEL LOW MOVES
EASTWARD SUNDAY NIGHT INTO MONDAY, THE SHOWERS WILL CHANGE MORE
INTO A STRATIFORM RAIN, WITH THE HEAVIEST RAINFALL EXPECTED OVER
NORTH CENTRAL MT. THERE IS ALSO A MARGINAL RISK FOR EXCESSIVE
RAINFALL THAT COULD CAUSE FLASH FLOODING SUNDAY NIGHT INTO MON
OVER NORTH CENTRAL MT.
DRIER AND WARMER CONDITIONS DEVELOP MID WEEK, WITH AFTERNOON
TEMPERATURES CLOSE TO 10 DEGREES ABOVE NORMAL BY THURSDAY. BY NEXT
FRIDAY, ANOTHER UPPER LEVEL TROF WILL START TO MOVE SOUTHWARD INTO
THE PACIFIC NORTHWEST, RESULTING IN A MOIST SOUTHWESTERLY FLOW
OVER MONTANA. THUS THE CHANCES FOR PRECIPITATION WILL START TO
INCREASE ONCE AGAIN NEXT FRI/SAT.
- FORECAST CONFIDENCE & SCENARIOS:
THE MAIN CONCERN ON SUNDAY FOR ANY SEVERE STORMS WILL BE STRONG
WIND GUSTS. THIS SYSTEM ON SUNDAY WILL NOT BE AS STRONG AS THE
WEATHER SYSTEM THAT WENT THROUGH THE CWA ON WEDNESDAY, NEVER THE
LESS, AN ISOLATED SEVERE STORM IS POSSIBLE. ADDITIONALLY, SOME
STORMS COULD ALSO PRODUCE HEAVY RAINFALL. BY MONDAY NIGHT, THE
NORTHERN PORTIONS OF NORTH CENTRAL MT COULD HAVE RECEIVED BETWEEN
1 AND 3 INCHES OF RAINFALL, WITH ISOLATED AMOUNTS NEAR 4 INCHES
POSSIBLE. OVERALL, FLOODING IS NOT EXPECTED, BUT IN AREAS THAT
EXCEED 3 INCHES, THE PROBABILITY OF MINOR FLOODING ON SMALL
STREAMS AND CREAKS STARTS TO INCREASE. BRUSDA
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 50 73 51 64 / 30 10 90 100
CTB 46 63 46 58 / 90 80 80 90
HLN 49 77 52 66 / 20 10 70 90
BZN 46 82 49 70 / 0 0 60 70
WYS 38 75 40 59 / 0 0 80 60
DLN 43 80 46 66 / 0 0 70 70
HVR 51 77 51 69 / 10 50 90 100
LWT 49 79 50 70 / 0 20 90 90
TFX WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING FOR PORTIONS OF SOUTHWEST MT ON SUNDAY.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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