467
FXUS65 KMSO 291805
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1205 PM MDT WED JUL 29 2026
DISCUSSION
KEY MESSAGES:
- HOT, DRY, AND SMOKY CONDITIONS CONTINUE WITH THE PERSISTENT
WEATHER PATTERN THROUGH FRIDAY.
- ISOLATED DRY THUNDERSTORM POTENTIAL: THIS AFTERNOON LEMHI
COUNTY/SW MONTANA, EXPANDING INTO WEST-CENTRAL MONTANA ON
THURSDAY AFTERNOON.
- ELEVATED WINDS AND FIRE WEATHER CONCERNS: THIS WEEKEND,
REGION- WIDE.
THIS AFTERNOON THROUGH FRIDAY: VARIABLE AIR QUALITY REMAINS THE
PRIMARY SHORT-TERM IMPACT ACROSS THE REGION AS A DRY, HOT
SOUTHWESTERLY FLOW PERSISTS OVER THE NORTHERN ROCKIES. THIS
PATTERN WILL HOLD THROUGH FRIDAY BEFORE A PACIFIC TROUGH MOVES
ONSHORE SATURDAY, BREAKING DOWN THE DOMINANT UPPER-LEVEL RIDGE OF
HIGH PRESSURE. HISTORICALLY, SYNOPTIC RIDGE BREAKDOWNS FOLLOWING
AN EXTENDED PERIOD OF HOT, DRY WEATHER SIGNIFICANTLY ELEVATE FIRE
WEATHER CONCERNS.
THERE WILL BE JUST ENOUGH MONSOONAL MOISTURE FOR ISOLATED
THUNDERSTORMS THIS AFTERNOON AND EVENING FROM LEMHI COUNTY INTO
SOUTHWEST MONTANA. THIS MOISTURE PUSHES NORTHWARD ON THURSDAY TO
INCLUDE AREAS EAST OF US 93 AND SOUTH HIGHWAY 200. GUSTY OUTFLOW
WINDS OF 40-50 MPH WILL BE COMMON NEAR ANY THUNDERSTORMS WITH A
MARGINAL CHANCE (5%) OF SEVERE GUSTS OVER 60 MPH. DRY LIGHTNING
IGNITIONS WILL BE AN ADDITIONAL HAZARD.
SATURDAY THROUGH EARLY NEXT WEEK: WINDS WILL INCREASE ON SATURDAY
AS THE MAIN PACIFIC TROUGH ADVANCES EASTWARD. THE STRONGEST WINDS
WILL ACCOMPANY AND FOLLOW A DRY COLD-FRONTAL PASSAGE SATURDAY
AFTERNOON INTO SUNDAY, WITH WIDESPREAD WESTERLY WINDS SUSTAINED
AT 10 TO 25 MPH AND GUSTS REACHING 25 TO 40 MPH ACROSS THE REGION.
THE COMBINATION OF GUSTY WINDS, PERSISTENT LOW RELATIVE HUMIDITY,
AND DRY FUELS WILL CREATE CRITICAL FIRE WEATHER CONDITIONS,
ACCORDINGLY FIRE WEATHER WATCHES HAVE BEEN ISSUED. ADDITIONALLY,
WINDS WILL PRODUCE HAZARDOUS, CHOPPY WATER ON AREA LAKES AND
RIVERS.
THIS SYSTEM WILL REMAIN PREDOMINANTLY DRY WITH NO SIGNIFICANT
PRECIPITATION EXPECTED. HOWEVER, POST-FRONTAL COLD AIR ADVECTION
WILL DROP TEMPERATURES 10 TO 20 DEGREES FOR SUNDAY AND MONDAY,
RETURNING HIGH TEMPERATURES TO SLIGHTLY BELOW SEASONAL AVERAGES.
AVIATION
HIGH DENSITY ALTITUDES AND WIDESPREAD VISIBILITY
REDUCTIONS DUE TO WILDFIRE SMOKE WILL PERSIST ACROSS REGIONAL
TERMINALS THROUGH SATURDAY.
A HIGH-BASED CONVECTIVE THREAT DEVELOPS THIS AFTERNOON/EVENING
MAINLY SOUTH OF A LINE FROM BUTTE TO SALMON. HIGH CLOUD BASES
(10,000-12,000 FT AGL) WILL KEEP PRECIPITATION MINIMAL AT THE
SURFACE, BUT INVERTED-V SOUNDINGS WILL PROMOTE ISOLATED DRY
THUNDERSTORMS CAPABLE OF PRODUCING STRONG, ERRATIC OUTFLOW GUSTS
UP TO 35-45 KT. A SIMILAR THREAT EXISTS ON THURSDAY
AFTERNOON/EVENING BUT THE COVERAGE AREA WILL EXPAND NORTHWARD
GENERALLY EAST OF US 93 AND SOUTH OF HIGHWAY 200.
NOTE: AMD NOT SKED FOR KGPI DUE TO MISSING METARS DURING RUNWAY
MAINTENANCE.
MSO WATCHES/WARNINGS/ADVISORIES
MT...FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY
EVENING FOR BITTERROOT...EAST LOLO...FLATHEAD RESERVATION...
FLATHEAD/GLACIER PARK...KOOTENAI...WEST LOLO.
FIRE WEATHER WATCH FROM SATURDAY AFTERNOON THROUGH SUNDAY
EVENING FOR DEERLODGE/WEST BEAVERHEAD...EAST BEAVERHEAD.
ID...FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING FOR CLEARWATER/NEZ PERCE...PALOUSE/HELLS CANYON.
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