409
FXUS65 KTFX 081742
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1142 AM MDT SAT AUG 8 2026
AVIATION SECTION UPDATED.
KEY MESSAGES
- ANOTHER WARM AND DRY DAY, WITH AREAS OF SMOKE TODAY.
- TEMPERATURES START TO COOL OFF BY THE MIDDLE OF NEXT WEEK.
- THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL INCREASE BY THE
MIDDLE OF NEXT WEEK AS WELL, WITH THE BEST AREA FOR
PRECIPITATION TO FALL BEING OVER NORTH CENTRAL MT.
DISCUSSION
/ISSUED 347 AM MDT SAT AUG 8 2026/
- METEOROLOGICAL OVERVIEW:
THE SUMMERTIME UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO
RESIDE OVER THE GREAT BASIN FOR A FEW MORE DAYS, BEFORE GRADUALLY
BREAKING DOWN A BIT BY THE MIDDLE OF NEXT WEEK. AFTERNOON
TEMPERATURES WILL BE ON THE WARM SIDE TODAY, BUT I DID LOWER THE
VALLEYS OF SOUTHWEST MT TODAY A FEW DEGREES BELOW GUIDANCE, WITH
THE THICK SMOKE, AFTERNOON TEMPERATURES ARE NOT GETTING QUITE AS
WARM AS MODELS PROG. OTHERWISE, THERE IS ABOUT A 10 PERCENT CHANCE
FOR A DRY THUNDERSTORM NEAR THE MT/ID BORDER WEST OF MONIDA PASS
TOWARDS EVENING. EXPECT A WIND SHIFT OVER NORTH CENTRAL MT AROUND
MID DAY, THIS WILL KEEP AFTERNOON TEMPERATURES JUST A BIT LOWER
OVER THE NORTH TODAY AS WELL.
FOR SUNDAY THROUGH TUESDAY, A VERY GRADUAL AND SLOW COOLING TREND
IS EXPECTED, ALONG WITH MOSTLY DRY CONDITIONS.
FOR WEDNESDAY THROUGH SATURDAY, AN UPPER LEVEL TROF OF LOW
PRESSURE IS EXPECTED TO MOVE SOUTHWARD INTO THE NORTHERN PORTIONS
OF MT BY THURSDAY. THIS WILL RESULT IN QUITE A BIT COOLER
TEMPERATURES, ESPECIALLY OVER THE NORTHERN PORTIONS OF THE CWA.
TODAY, THE 00Z RUN OF THE GFS IS ABOUT 30 DEGREES COLDER WITH
AFTERNOON TEMPERATURES THAN YESTERDAY'S 00Z RUN OVER NORTH
CENTRAL MT. OVER SOUTHWEST MT, IT SHOULD TURN COOLER, JUST NOT AS
COOL AS NORTH CENTRAL MT. ADDITIONALLY, THE GFS/EC ARE AVERAGING
BETWEEN 0.10 AND 0.20 INCHES OF PRECIPITATION OVER NORTH CENTRAL
MT FROM WED INTO THU. THIS ISN'T A LOT OF PRECIPITATION, BUT MORE
THAN WHAT HAS FALLEN RECENTLY. THE UPPER LEVEL TROF COULD EXIT
THE AREA BY NEXT SATURDAY, RESULTING IN AN UNSTABLE SOUTHWESTERLY
FLOW ALOFT SETTING UP.
- FORECAST CONFIDENCE & SCENARIOS:
WITH THE 00Z GFS TODAY PROGGING TEMPERATURES ABOUT 30 DEGREES
COLDER THAN YESTERDAY OVER NORTH CENTRAL MT BY NEXT THURSDAY,
CONFIDENCE IS A BIT UNCERTAIN ABOUT THE TIMING/STRENGTH OF THE
COLDER AIR BY THE MIDDLE OF NEXT WEEK. ADDITIONALLY, HOW FAR SOUTH
DOES THE PRECIPITATION GO BEFORE CUTTING OFF. BRUSDA
AVIATION
08/18Z TAF PERIOD
VFR CONDITIONS WILL PREVAIL ACROSS ALL TERMINALS DURING THIS TAF
PERIOD OUTSIDE OF THE KBZN AND KEKS TERMINALS. THROUGH AT LEAST
09/06Z SMOKE FROM WILDFIRES WILL REDUCE VISIBILITY TO MVFR LEVELS
AND PERIODICALLY TO IFR-LEVELS AT THE KEKS AND KBZN TERMINALS. AT
ALL OF THE TAF SITES DURING THIS TAF PERIOD THERE WILL BE MULTIPLE
WIND SHIFTS. ACROSS MOST OF THE TAF SITES SMOKE FROM WILDFIRES WILL
REDUCE SLANTWISE VISIBILITY DURING THE MAJORITY OF THIS TAF
PERIOD. DURING THE MAJORITY OF THIS TAF PERIOD THERE WILL BE
MOUNTAIN OBSCURATION ACROSS SOUTHWESTERN MONTANA DUE TO SMOKE.
-IG
KGTF: FOR THE MOST PART TODAY WINDS WILL STAY BELOW 15 KTS. THE
MAIN CONCERN WILL BE SHIFTING WINDS. WINDS SHIFT TO THE NORTH
AROUND 21Z, SHIFT TO MORE NORTHEASTERLY AROUND 00Z, AND SHIFT TO
MORE EASTERLY BY 03Z. THE PROBABILITY FOR EXCEEDING A 15 KT
CROSSWIND IS 30% BETWEEN 18Z AND 03Z. -IG
FIRE WEATHER
A RED FLAG WARNING REMAINS IN EFFECT FOR THE SOUTHERN DISTRICTS
THROUGH TODAY. THE COMBINATION OF GUSTY AFTERNOON WINDS, LOW
HUMIDITY AND HOT TEMPERATURES WILL CREATE CRITICAL FIRE WEATHER
CONDITONS. BECAUSE OF ALL THE SMOKE, SOME LOCATIONS MIGHT NOT MIX
THE WINDS ALOFT TODAY, RESULTING IN THE POTENTIAL FOR THE RED FLAG
WARNING TO BE CANCELLED EARLY. EXPECT SOME WIND SHIFTS OVER NORTH
CENTRAL MT TODAY AND SUNDAY, WITH COOLER TEMPERATURES/WETTER
CONDITIONS OVER NORTH CENTRAL AS WELL BY THE MIDDLE OF NEXT WEEK.
BRUSDA
PRELIMINARY POINT TEMPS/POPS
GTF 91 56 86 55 / 0 0 0 0
CTB 83 51 79 50 / 0 0 0 0
HLN 93 57 90 55 / 0 0 0 0
BZN 93 54 90 52 / 0 0 0 0
WYS 88 44 86 44 / 0 0 0 0
DLN 91 52 88 52 / 0 0 0 0
HVR 90 56 87 53 / 0 0 0 0
LWT 87 54 83 52 / 0 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR CENTRAL AND
EASTERN LEWIS AND CLARK NATIONAL FOREST AREAS-HELENA AND
TOWNSEND RANGER DISTRICTS OF THE HELENA NATIONAL FOREST-LINCOLN
RANGER DISTRICT OF THE HELENA NATIONAL FOREST.
HTTP://WWW.WEATHER.GOV/GREATFALLS
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