866
FXUS65 KTFX 122050
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
250 PM MDT FRI SEP 12 2025
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS
NORTH-CENTRAL AND CENTRAL MONTANA THROUGH THE EVENING.
- ABOVE NORMAL TEMPERATURES AND DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THE WEEKEND.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THUNDERSTORMS ARE ALREADY UNDERWAY ACROSS PORTIONS OF CENTRAL AND
NORTH-CENTRAL MONTANA WITH THE STRONGEST STORMS EXPECTED IN JUDITH
BASIN, FERGUS, AND BLAINE COUNTIES. THE LATEST CAMS SHOW MLCAPE IN
THE 1500-2000 J/KG RANGE WHICH IS MORE THAN SUFFICIENT TO KICK OF
STRONGER STORMS. DUE TO A LACK OF SHEAR, THESE STORMS ARE QUASI-
STATIONARY AT THE MOMENT WHICH MAY BECOME A CONCERN FOR LOCALIZED
FLASH FLOODING UNDER STRONGER CELLS.
AN ACTIVE PATTERN WILL CONTINUE THROUGH THE WEEKEND WITH DAILY
CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE REGION. ABOVE
NORMAL TEMPERATURES WILL PERSIST ACROSS NORTH-CENTRAL AND CENTRAL
MONTANA WITH MORE SEASONABLY TEMPERATURES EXPECTED ACROSS
SOUTHWEST MONTANA.
- FORECAST CONFIDENCE & SCENARIOS:
RIGHT NOW THE MAIN CONCERN ARE THE STORMS FIRING OFF OF THE LITTLE
BELT AND BEARS PAW MOUNTAINS. SOME GUSTY WINDS, GENERALLY LESS
THAN 40 MPH, ARE EXPECTED ALONG WITH SMALL HAIL. THERE IS A
CONCERN THAT A COUPLE OF THESE THUNDERSTORMS MAY GET STRONGER AND
PRODUCE LOCALLY STRONGER WIND GUSTS UP TO 50 MPH AND LARGER HAIL
UP TO 1 INCH. AT THIS TIME, WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED WITH THE BIGGEST THREAT FOR SEVERE THUNDERSTORMS OFF TO
THE EAST OF OUR AREA.
OTHERWISE THE PRIMARY CONCERN IS HOW SLOW THESE STORMS ARE
MOVING. QUITE A FEW OF THE STORMS THAT HAVE DEVELOPED HAVE STORM
MOTIONS OF 5 TO 10 MPH WHICH IS EXPECTED GIVEN THE LACK OF SHEAR
BUT IT ALSO MEANS THAT THE THREAT FOR FLOODING STARTS TO SLOWLY
TICK UP THE LONGER THESE STORMS STALL OVER ONE AREA. FOR NOW,
THERE IS LOW CONFIDENCE (<20%) IN ANY SIGNIFICANT FLOODING.
HOWEVER, LOCALIZED MINOR FLASH FLOODING IS POSSIBLE SHOULD THE
STRONGER STORMS PERSIST LONG ENOUGH. THIS WILL BE SOMETHING THAT
IS MONITORED CLOSELY AS THE AFTERNOON AND EVENING PROGRESSES.
-THOR
AVIATION
12/12Z TAF PERIOD
VFR CONDITIONS WILL PREDOMINATELY PREVAIL THROUGHOUT THE 1212/1312
TAF PERIOD; HOWEVER, BRIEF PERIODS OF MVFR/LOW-VFR CONDITIONS ARE
POSSIBLE BENEATH SHOWER AND THUNDERSTORM ACTIVITY IN ADDITION TO
GUSTY AND ERRATIC WINDS. SHOWER AND THUNDERSTORM COVERAGE WILL
LARGELY BE ISOLATED TO WIDELY SCATTERED OVER THE NEXT 18-24 HOURS,
WITH THE GREATEST AREAL COVERAGE OCCURRING BETWEEN 21-24Z THIS
AFTERNOON. WHILE WIDESPREAD MOUNTAIN OBSCURATION IS NOT EXPECTED
THERE WILL BE PERIODS OF OBSCURATION BENEATH/NEAR PRECIPITATION.
- MOLDAN
HYDROLOGY
A FEW HEAVY SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY. WHILE
UNLIKELY, SHOULD ONE OF THE HEAVIEST RAIN SHOWERS HIT A BURN SCAR
SOME FLASH FLOODING MAY BE POSSIBLE. LUDWIG
PRELIMINARY POINT TEMPS/POPS
GTF 48 77 51 80 / 20 10 10 10
CTB 44 77 48 78 / 20 10 10 10
HLN 49 77 50 79 / 20 20 10 10
BZN 44 71 45 77 / 10 30 10 10
WYS 36 63 33 67 / 10 40 10 10
DLN 41 71 43 73 / 10 20 0 10
HVR 49 76 52 79 / 30 20 20 10
LWT 48 69 48 76 / 40 50 20 10
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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