946
FXUS65 KTFX 192343
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
543 PM MDT WED AUG 19 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- MOSTLY DRY THROUGH THURSDAY, WITH THUNDERSTORMS RETURNING TO
SOUTHWESTERN MONTANA FRIDAY.
- ADDITIONAL THUNDERSTORMS EXPECTED SATURDAY, SOME OF WHICH
COULD BE STRONG AND PRODUCE HEAVY RAINFALL.
- TEMPERATURES WILL GENERALLY BE SEASONABLE, THOUGH ABOVE
AVERAGE TEMPERATURES ARE EXPECTED FRIDAY AND SATURDAY.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
UPPER LEVEL RIDGING HAS CONTINUED TO BUILD ACROSS THE WESTERN US
TODAY, WHICH HAS RESULTED IN GENERALLY CLEAR, ALBEIT SLIGHTLY
SMOKY, SKIES ACROSS NORTH CENTRAL AND SOUTHWESTERN MONTANA TODAY.
ASIDE FROM A LOW RISK OF A THUNDERSTORM ALONG THE HI LINE TONIGHT,
EXPECT THE REMAINDER OF THE DAY TODAY TO BE DRY AND SEASONABLY
WARM, WHICH WILL CONTINUE INTO THURSDAY AS WELL.
ALTHOUGH THE RIDGE PEAKS FRIDAY, MONSOONAL MOISTURE WILL BEGIN TO
WORK INTO THE AREA FRIDAY, WHICH WILL HELP KICK OFF A FEW
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS, MAINLY ACROSS
SOUTHWESTERN AND CENTRAL MONTANA. WHILE THESE SHOULD DISSIPATE
WITH THE LOSS OF DAYTIME HEATING, MONSOONAL MOISTURE WILL REMAIN
IN PLACE ON SATURDAY AS THE RIDGE WANES, RESULTING IN A BREEZY DAY
WITH WIDESPREAD AFTERNOON THUNDERSTORMS, SOME OF WHICH MAY
PRODUCE SOME HEAVY RAINFALL AND/OR BE ON THE STRONG SIDE.
AFTER THE RIDGE WEAKENS, ZONAL FLOW WILL SET UP BRIEFLY ACROSS
THE AREA BEFORE RIDGING RETURNS EARLY NEXT WEEK. EXPECT
TEMPERATURES TO REMAIN AROUND AVERAGE FOR LATE AUGUST, WITH
PERIODIC CHANCES FOR AFTERNOON THUNDERSTORMS. LUDWIG
- FORECAST CONFIDENCE & SCENARIOS:
ON SATURDAY THERE IS A 30 - 45% CHANCE FOR THUNDERSTORMS IN
SOUTHWESTERN MONTANA. ON SATURDAY THERE IS A 15 - 30% CHANCE FOR
THUNDERSTORMS ACROSS NORTH-CENTRAL AND CENTRAL MONTANA. ON SUNDAY
THERE IS A 25 - 35% CHANCE FOR THUNDERSTORMS ACROSS CENTRAL AND
SOUTHWESTERN MONTANA. ON SUNDAY THERE IS A 15 - 20% CHANCE FOR
THUNDERSTORMS ACROSS NORTH-CENTRAL MONTANA. SATURDAY THROUGH
SUNDAY THERE IS A 25 - 50% CHANCE FOR A QUARTER INCH OF RAIN OR
GREATER ACROSS SOUTHWESTERN MONTANA. PRECIPITABLE WATER (PWAT)
WILL INCREASE THIS WEEKEND WHICH HAS TO POTENTIAL TO LEAD TO
LOCALIZED FLASH FLOODING ON BURN SCARS WITH THE STRONGER
THUNDERSTORMS.
ON SATURDAY THERE IS GREATER THAN A 50% CHANCE FOR WIND GUSTS OF 25
MPH OR GREATER ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN
MONTANA. ON SATURDAY IN NORTHERN BLAINE COUNTY THERE IS GREATER
THAN A 70% CHANCE FOR WIND GUSTS OF 40 MPH OR GREATER. ON SUNDAY
THERE IS GREATER THAN A 50% CHANCE FOR WIND GUSTS OF 30 MPH OR
GREATER ACROSS NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA.
ON SUNDAY THERE IS A 50 - 75% CHANCE FOR WIND GUSTS OF 40 MPH OR
GREATER ALONG THE HI-LINE, SOUTHERN ROCKY MOUNTAIN FRONT, AND IN
CASCADE AND JUDITH BASIN COUNTY. ON SUNDAY AFTERNOON ACROSS NORTH-
CENTRAL MONTANA THERE IS A 15 - 30% CHANCE FOR WIND SPEEDS OF 15
MPH OR GREATER COMBINED WITH RELATIVE HUMIDITY OF 20% OR LESS (RED
FLAG CRITERIA). ON SUNDAY THERE IS LOW CONFIDENCE IN RELATIVE
HUMIDITY REACHING CRITICAL LEVELS AND SO AT THIS TIME IT APPEARS
ON SUNDAY THERE WILL BE AT LEAST ELEVATED FIRE WEATHER CONCERNS
DUE TO GUSTY WINDS. -IG
AVIATION
20/00Z TAF PERIOD
VFR CONDITIONS ARE EXPECTED ACROSS THE CWA THROUGH THE PERIOD.
AREAS OF HIGH CLOUDS WILL AFFECT NORTH CENTRAL MT OVERNIGHT.
ADDITIONALLY, SMOKE CONTINUES TO MOVE INTO THE CWA FROM THE WEST,
REDUCING DISTANT VISIBILITY AND OBSCURING MOUNTAINS/PASSES ACROSS
THE CWA.
FOR KGTF: WINDS WILL GENERALLY BE LIGHT OVER THE NEXT 24 HOURS.
VARIABLE WINDS THIS EVENING AND OVERNIGHT WILL GENERALLY BECOME
A SOUTHWESTERLY WIND DIRECTION ON THURSDAY MORNING. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 56 91 56 87 / 0 0 0 0
CTB 52 84 52 82 / 0 0 0 0
HLN 53 91 58 93 / 0 0 0 0
BZN 50 90 54 93 / 0 0 0 0
WYS 39 85 45 90 / 0 0 0 0
DLN 49 87 53 89 / 0 0 0 0
HVR 55 91 56 89 / 0 0 0 0
LWT 53 88 55 85 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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