571
FXUS65 KTFX 100532
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1132 PM MDT SUN AUG 9 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- IT WILL BE HOT, DRY, AND HAZY THROUGH TUESDAY.
- A BRIEF COOL DOWN IS EXPECTED WEDNESDAY THROUGH NEXT FRIDAY
WITH ISOLATED SHOWERS RETURNING.
- NEXT WEEKEND THERE WILL BE ISOLATED SHOWERS AND THUNDERSTORMS
WITH WARMER TEMPERATURES.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
THIS AFTERNOON THERE IS AN UPPER-LEVEL RIDGE OVER NORTH-CENTRAL,
CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL BRING SLIGHTLY COOLER
TEMPERATURES TO THE AREA WITH DRY WEATHER. ON MONDAY AND TUESDAY
THE UPPER-LEVEL RIDGE REMAINS OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA. THIS WILL WILL KEEP WARM AND DRY WEATHER FOR
THE AREA ON MONDAY AND TUESDAY. SMOKE FROM REGIONAL WILDFIRES
WILL BE AROUND THROUGHOUT THE NEXT FEW DAYS. ON WEDNESDAY THE
UPPER-LEVEL RIDGE REMAINS OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA WITH AN UPPER-LEVEL TROUGH APPROACHING THE
AREA. THIS WILL BEGIN TO BRING COOLER AIR AND MONSOONAL MOISTURE
TO THE AREA ON WEDNESDAY.
THURSDAY THROUGH FRIDAY AN UPPER-LEVEL TROUGH MOVES OVER NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. THIS WILL BRING
PRECIPITATION CHANCES AND COOLER TEMPERATURES (WELL-BELOW SEASONAL
AVERAGES) TO THE AREA THURSDAY THROUGH FRIDAY. SEE THE FORECAST
CONFIDENCE & SCENARIOS SECTION FOR DETAILS. NEXT WEEKEND AN UPPER-
LEVEL RIDGE BUILDS BACK IN OVER NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA WITH SOUTHWEST FLOW ALOFT. THIS WILL BRING
DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS WITH TEMPERATURES
WARMING UP ON SATURDAY AND NEXT SUNDAY. -IG
- FORECAST CONFIDENCE & SCENARIOS:
TODAY AND TOMORROW ACROSS NORTH-CENTRAL, CENTRAL, AND
SOUTHWESTERN MONTANA MINIMUM AFTERNOON HUMIDITY WILL BE NEAR
CRITICAL LEVELS. THIS COMBINED WIND GUSTS THAT WILL PEAK AT AROUND
20 MPH WILL BRING ELEVATED FIRE WEATHER CONDITIONS TO THE AREA.
THE WIND DIRECTION WILL ALSO PERIODICALLY SHIFT OVER THE NEXT 24
TO 48 HOURS. THE GREATEST RISK FOR ELEVATED TO NEAR CRITICAL FIRE
WEATHER CONDITIONS IS IN SOUTHWESTERN MONTANA THIS AFTERNOON
THROUGH TUESDAY.
WEDNESDAY THROUGH FRIDAY THERE ARE DIFFERENCES IN THE TRACK OF
THE UPPER-LEVEL TROUGH IN ENSEMBLES AND DETERMINISTIC MODELS. ON
THURSDAY AND FRIDAY ONE CLUSTER HAS ZONAL FLOW OVER MONTANA WHILE
THE OTHER THREE HAVE AN UPPER-LEVEL TROUGH APPROACHING MONTANA. IN
THE ZONAL FLOW SCENARIO TEMPERATURES WILL REMAIN AT ABOUT
SEASONAL AVERAGES WITH A FEW ISOLATED SHOWERS. IN THE UPPER-LEVEL
TROUGH SCENARIO TEMPERATURES WILL COOL OFF TO AT LEAST BELOW
SEASONAL AVERAGES WITH MORE WIDESPREAD SHOWERS. ANOTHER AREA OF
UNCERTAINTY WITH THIS TROUGH IS HOW FAR SOUTH IT TRACKS. THE
FURTHER SOUTH IT TRACKS, THE FURTHER SOUTH THE PRECIPITATION WILL
BE AND IT WILL RESULT IN COOLER TEMPERATURES THAN A MORE NORTHERLY
TRACK.
ON WEDNESDAY THERE IS A 30 - 45% CHANCE FOR THUNDERSTORMS ACROSS
THE HI-LINE AND A 20 - 30% CHANCE FOR THUNDERSTORMS ACROSS THE
REST OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. ON
THURSDAY THERE IS A 20 - 40% CHANCE FOR THUNDERSTORMS ACROSS MOST
OF NORTH-CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA. ON FRIDAY
THERE IS A 35% CHANCE FOR THUNDERSTORMS ACROSS CENTRAL AND
SOUTHWESTERN MONTANA. WEDNESDAY THROUGH FRIDAY THERE IS A 40 - 80%
CHANCE FOR A QUARTER INCH OF RAIN OR GREATER ACROSS NORTH-
CENTRAL, CENTRAL, AND SOUTHWESTERN MONTANA WITH THE HIGHEST
PROBABILITIES ALONG THE HI-LINE. WEDNESDAY THROUGH FRIDAY THERE IS
A 50 - 70% CHANCE FOR ONE HALF INCH OR RAIN OR GREATER ALONG THE
HI-LINE AND ACROSS CHOTEAU, JUDITH BASIN, AND FERGUS COUNTIES. ON
THURSDAY AND FRIDAY THERE IS GREATER THAN A 50% CHANCE FOR HIGH
TEMPERATURES OF 70 DEGREES OR LOWER ACROSS THE PLAINS OF NORTH-
CENTRAL MONTANA. -IG
AVIATION
10/06Z TAF PERIOD
OVERALL, A WESTERLY FLOW ALOFT WILL RESIDE OVER MT THROUGH THE
PERIOD. THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS ON MONDAY,
MOSTLY NORTH OF THE US/CANADIAN BORDER. OTHERWISE, SMOKE WILL BE
THE MAIN IMPACT, WITH SOUTHWEST MT HAVING IFR VISIBILITY AT TIMES
BECAUSE OF SMOKE. MOUNTAINS/PASSES WILL BE OBSCURED ACROSS THE CWA
THROUGH THE PERIOD BECAUSE OF SMOKE.
FOR KGTF: LIGHT EAST WINDS EARLY THIS MORNING WILL BECOME WESTERLY
BY LATE MORNING. OVERALL WIND SPEEDS WILL WILL GENERALLY BE LESS
THAN 15 KNOTS THROUGH THE PERIOD, WITH JUST A FEW ISOLATED GUSTS
NEAR 20 KNOTS ON MON AFTERNOON. OVERALL THE PROBABILITY OF CROSS
WINDS OVER 15 KNOTS IS LESS THAN 20 PERCENT. BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 54 89 55 85 / 0 0 0 0
CTB 51 82 50 77 / 0 0 0 0
HLN 55 88 54 89 / 0 0 0 0
BZN 52 90 52 90 / 0 0 0 0
WYS 44 84 42 85 / 0 0 0 0
DLN 51 88 50 88 / 0 0 0 0
HVR 53 88 54 85 / 0 0 0 0
LWT 52 85 53 82 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
NONE.
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