752
FXUS65 KMSO 081929
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
129 PM MDT SAT AUG 8 2026
DISCUSSION
KEY MESSAGES:
- NEAR-CRITICAL TO CRITICAL FIRE WEATHER PEAKS THIS AFTERNOON AND
EVENING FROM GUSTY WINDS AND EXCEPTIONALLY DRY CONDITIONS.
- WIDESPREAD SMOKE CONTINUES TO DEGRADE AIR QUALITY AND
VISIBILITY DRIVEN BY VARIABLE UPSTREAM FIRE ACTIVITY IN WA, OR,
AND BC.
- WEDNESDAY WIND SHIFT IN SW MT ENHANCES FIRE WEATHER CONCERNS
POTENTIALLY DRIVING ACTIVE FIRES TOWARD NEW FUEL SOURCES.
A SUBTLE UPPER-LEVEL WAVE AND WEAK FRONTAL PASSAGE WILL FURTHER
ENHANCE CRITICAL FIRE WEATHER CONDITIONS THIS AFTERNOON ACROSS THE
REGION. SURFACE WIND GUSTS UP TO 30 MPH ARE EXPECTED,
PARTICULARLY ACROSS HIGHER TERRAIN. THESE WINDS COMBINED WITH
EXCEPTIONALLY DRY FUELS, WARM TEMPERATURES, AND CONTINUOUSLY POOR
OVERNIGHT RECOVERIES OFF VALLEY FLOORS WILL SUSTAIN CRITICAL
THRESHOLDS THROUGH THE LATE EVENING HOURS. THERMAL BELTS WILL
CONTINUE TO INFLUENCE POOR OVERNIGHT RECOVERIES THOUGH
INCREASINGLY ACTIVE FLOW ALOFT OVER THE NEXT SEVERAL DAYS WILL
CONTINUE TO SLOWLY TAMPER THE STRENGTH OF THESE STABLE INVERSION
ENVIRONMENTS.
WIDESPREAD WILDFIRE SMOKE WILL CONTINUE ACROSS THE NORTHERN
ROCKIES, WITH SURFACE IMPACTS DEPENDENT ON UPSTREAM PLUME
TRANSPORT FROM REGIONAL WILDFIRES ACROSS THE PACIFIC NORTHWEST AND
THE TIMING OF THESE PLUMES ENTERING THE REGION. IN THE NEAR-
TERM, VERY DENSE SMOKE IS ANTICIPATED IN NW MONTANA ON SUNDAY.
A GRADUAL MOISTENING AND SLIGHT COOLING TREND IS EXPECTED NEXT
WEEK. HOWEVER, THIS MODERATING AIRMASS IS UNLIKELY TO
SIGNIFICANTLY SUPPRESS ONGOING LOCAL AND REGIONAL WILDFIRE
ACTIVITY. LIGHT TO MODERATE WINDS WILL PERSIST. FURTHERMORE, A
WEAK UPPER LEVEL DISTURBANCE ON MONDAY WILL INCREASE WIND SPEEDS
AND GUST POTENTIAL OUT OF THE WEST ONCE AGAIN ESPECIALLY IN
SOUTHWEST MONTANA. A SHALLOW LOW-LEVEL NORTH AND NORTHEASTERLY
PUSH IS ANTICIPATED FOR WEDNESDAY CREATING A DISTINCT SHIFT IN
WIND DIRECTION WHICH COULD BE PROBLEMATIC FOR CERTAIN SLOPE
ALIGNMENTS AND FUEL AVAILABILITY ALONG ACTIVE FLANKS OF ONGOING
FIRE ACTIVITY IN SOUTHWEST MONTANA AND AREAS NEAR THE CONTINENTAL
DIVIDE.
THERE IS MODEST CONFIDENCE FOR SOME NOTABLE FIRE SUPPRESSION DUE
TO PRECIPITATION CHANCES AND COLDER TEMPERATURES INBOUND WITH THE
MID-LATE WEEK TROUGH. THE BEST CHANCES FOR COOLER AND WETTER
CONDITIONS REMAINS CONFINED TO AREAS NORTH AND ALONG THE CANADIAN
BORDER INTO THE FLATHEAD NATIONAL FOREST CLOSER TO THE COLD CORE
WHERE HIGHER MOISTURE AVAILABILITY AND LIFTING MECHANISMS OF THE
FORECAST TROUGH ARE EXPECTED. THE TIME PERIOD FOR THIS WEATHER
SYSTEM WOULD BE WEDNESDAY INTO THURSDAY THOUGH MODEL AGREEMENT IN
EXACT IMPACTS AND TIMING OF THIS WEATHER SYSTEM ARE STILL NOT
TOTALLY LOCKED-IN.
AVIATION
A WEAK DISTURBANCE MOVING THROUGH THE REGION WILL
ENHANCE WINDS AND HELP CLEAR OUT SOME OF THE SMOKE THIS AFTERNOON.
THIS IMPROVEMENT WILL PROBABLY ONLY BE A SHORT LIVED PERIOD AS
FIRES FROM WASHINGTON AND OREGON WILL CAUSE MORE SMOKE TO SETTLE
BACK INTO THE AREA TONIGHT. WEAKER WINDS ON SUNDAY WILL LIMIT ANY
SMOKE IMPROVEMENT. THE INVERSION LAYER ALONG WITH THE SMOKE IS
CREATING A FALSE CEILING IN KBTM. MOST TERMINALS WILL EXPERIENCE
WIND GUSTS UP TO 20 KNOTS THIS AFTERNOON INTO THE EARLY EVENING
THEN THE WINDS WILL BECOME VARIABLE.
MSO WATCHES/WARNINGS/ADVISORIES
MT...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR BITTERROOT...
DEERLODGE/WEST BEAVERHEAD...EAST BEAVERHEAD...EAST LOLO...
FLATHEAD RESERVATION...WEST LOLO.
ID...RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR PALOUSE/HELLS
CANYON.
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