378
FXUS65 KMSO 290837
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
237 AM MDT WED JUL 29 2026
DISCUSSION
KEY MESSAGES:
- HOT, DRY, AND SMOKY CONDITIONS CONTINUE WITH THE PERSISTENT
WEATHER PATTERN THROUGH SATURDAY.
- DRY THUNDERSTORM POTENTIAL: THURSDAY AFTERNOON THROUGH FRIDAY
MORNING ACROSS SOUTHWEST AND WEST-CENTRAL MONTANA.
- ELEVATED WINDS AND FIRE WEATHER: SATURDAY AND SUNDAY REGION-
WIDE.
AIR QUALITY REMAINS THE BIGGEST IMPACT IN THE SHORT TERM AS THE
NORTHERN ROCKIES IS STILL IN A DRY AND HOT SOUTHWESTERLY FLOW.
THIS PATTERN WILL CONTINUE THROUGH FRIDAY, THEN ON SATURDAY A
STATIONARY PACIFIC TROUGH IS EXPECTED TO MOVE ONSHORE AND SQUASH
THE HIGH PRESSURE RIDGE THAT HAS DOMINATED OUR WEATHER.
HISTORICALLY, RIDGE BREAKDOWN AFTER A PERIOD OF HOT AND DRY
WEATHER CAN LEAD TO ELEVATED FIRE WEATHER CONCERNS.
THURSDAY A SHORT WAVE EJECTING OFF THE PACIFIC LOW PRESSURE WILL
INTERACT WITH A FAVORABLE ATMOSPHERE: STRONG MID-LEVEL LAPSE
RATES AND WEAK TO MODERATE SHEAR. THE ATMOSPHERE IS VERY DRY AND
MODELS ARE NOT EXCITED ABOUT THUNDERSTORMS, THAT SAID THIS
PARTICULAR SETUP HAS IN THE PAST PRODUCED STRONG DRY THUNDERSTORMS.
THE MAIN THREATS WOULD BE DRY LIGHTNING AND STRONG OUTFLOW WIND
GUSTS. THE MOST FAVORABLE ATMOSPHERIC SETUP IS SOUTH AND EAST OF
THE MISSOULA VALLEY ESPECIALLY ALONG THE CONTINENTAL DIVIDE.
AS THE PACIFIC TROUGH PUSHES THROUGH THE REGION WINDS WILL
INCREASE SATURDAY. THE STRONGEST WINDS WILL HAPPEN POST DRY COLD
FRONT OVERNIGHT SATURDAY INTO SUNDAY. EXPECT WIDESPREAD WESTERLY
WINDS SUSTAINING 10-25 MPH WITH GUSTS OF 25 TO 40 MPH ACROSS THE
REGION. THIS WIND/ HEAT/ AND LOW RH COMBINATION WILL SIGNIFICANTLY
ELEVATE FIRE WEATHER CONCERNS AND CREATE HAZARDOUS, CHOPPY
CONDITIONS ON LAKES AND WATERWAYS. THIS SYSTEM WILL REMAIN MOSTLY
DRY WITH NO SIGNIFICANT OR NOTABLE PRECIPITATION EXPECTED, BUT
TEMPERATURES WILL DROP 10-20 DEGREES BEHIND THE FRONT FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES BACK TO NEAR AND JUST BELOW
NORMAL FOR THIS TIME OF YEAR.
AVIATION
WILDFIRE SMOKE REMAINS A PERSISTENT IMPACT TO THE
REGIONAL AIRSPACE. SLANT-RANGE AND SURFACE VISIBILITIES CONTINUE
TO BOTTOM OUT NEAR 5SM AT TIMES, ESPECIALLY PRONOUNCED DURING THE
LATE AFTERNOON THROUGH SUNSET AS OPTICAL DEPTH INCREASES AND THE
DAY'S FRESH SMOKE ARRIVES FROM FIRES BURNING IN OREGON AND
SOUTHWESTERN IDAHO. ANTICIPATE CONTINUED MOUNTAIN OBSCURATIONS.
RIDGETOP WINDS WILL REMAIN OUT OF THE WEST AND SOUTHWEST AT 10-20
KNOTS THROUGH THE FORECAST PERIOD. HOT TEMPERATURES WILL CONTINUE
TO INCREASE DENSITY ALTITUDES THROUGH SATURDAY IMPACTING AIRCRAFT
PERFORMANCE PARTICULARLY AT HIGHER ELEVATION TERMINALS AND
AIRFIELDS AS TEMPERATURES CONTINUE TO CREEP INTO THE MID AND UPPER
90S EACH DAY.
NOTE: AMD NOT SKED FOR KGPI DUE TO MISSING METARS DURING RUNWAY
MAINTENANCE.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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