948
FXUS65 KMSO 282002
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
202 PM MDT THU AUG 28 2025
DISCUSSION
KEY MESSAGES:
- LOCALLY DENSE FOG MAY REDUCE VISIBILITY, ESPECIALLY THE VALLEYS
OF NORTH-CENTRAL IDAHO FRIDAY MORNING
- BRIEF HEAVY RAIN IN NORTHWEST MONTANA/GLACIER NP FRIDAY
AFTERNOON AND EVENING
THE LOW-PRESSURE SYSTEM THAT BROUGHT WIDESPREAD RAIN TO THE
REGION CONTINUES ITS SLOW NORTHWARD TRACK THIS AFTERNOON. THE
STEADIEST SHOWERS ARE NOW CONCENTRATED NORTH OF THE I-90 CORRIDOR,
WHILE AREAS SOUTH OF I-90 ARE EXPERIENCING MORE SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS. OVER THE PAST 24 HOURS, RAINFALL
TOTALS HAVE GENERALLY RANGED FROM 0.10" TO NEARLY 1.00".
WITH ABUNDANT LOW-LEVEL MOISTURE STILL IN PLACE (DEWPOINTS ARE
NEAR 60F), ANY LOCATIONS THAT SEE SKIES CLEAR OUT TONIGHT WILL BE
PRONE TO DEVELOPING DENSE VALLEY FOG BY FRIDAY MORNING.
ON FRIDAY, THE LAST REMNANTS OF THE STORM SYSTEM WILL FOCUS OVER
NORTHWEST MONTANA. HIGH-RESOLUTION MODELS SUGGEST THAT DEVELOPING
AFTERNOON AND EVENING THUNDERSTORMS WILL BE CAPABLE OF PRODUCING
BRIEF BUT HEAVY DOWNPOURS. THIS COULD LEAD TO LOCALIZED RUNOFF
ISSUES, AND VISITORS IN GLACIER NATIONAL PARK SHOULD REMAIN
PARTICULARLY AWARE OF CHANGING CONDITIONS.
WEEKEND OUTLOOK & NEXT WEEK
A PATTERN CHANGE IS ON THE WAY FOR THE WEEKEND. HIGH PRESSURE
WILL BUILD ACROSS THE REGION, BRINGING AN END TO THE WET WEATHER
AND KICKING OFF A PRONOUNCED WARMING TREND. EXPECT CLEARING SKIES
AND PROGRESSIVELY WARMER TEMPERATURES THROUGH SATURDAY AND SUNDAY.
THE WARM AND DRY CONDITIONS ARE EXPECTED TO PERSIST THROUGH MOST
OF NEXT WEEK. FORECAST MODELS ARE BEGINNING TO SHOW BETTER
AGREEMENT ON A STRETCH OF LATE-SUMMER HEAT, WITH HIGH TEMPERATURES
LIKELY TO CLIMB 10-15 DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR.
AVIATION
RAIN SHOWERS WILL CONTINUE THROUGH THIS AFTERNOON AS
A MIDLEVEL CIRCULATION MOVES NORTH AND EAST OUT OF THE NORTHERN
ROCKIES. SOME SHOWERS ARE BRINGING VISIBILITY AND CEILINGS DOWN
INTO IFR TERRITORY. AVIATORS SHOULD EXPECT SHOWERS TO OBSCURE
TERRAIN THROUGHOUT THE NORTHERN ROCKIES AIRSPACE. ALTHOUGH MOST
PRECIPITATION HAS BEEN IN THE FORM OF STRATIFORM RAIN, KBTM AND
KMSO COULD SEE SOME WEAK CONVECTION WITH LIGHTNING AFTER ABOUT
28/2100Z THIS AFTERNOON (ABOUT 40 PERCENT CHANCE). GOING INTO
TONIGHT, THE FOCUS FOR RAINFALL WILL SHIFT NORTH, WITH KGPI
HANGING ONTO SHOWERS THROUGH ABOUT 29/0800Z. LOW LEVEL MOISTURE
FROM RAIN SHOWERS TODAY WILL MEAN CHANCES FOR FOG AND LOW STRATUS
DECKS IN THE MORNING AT ALL AREA TERMINALS. CHANCES FOR AFTERNOON
THUNDERSTORMS WILL SHIFT NORTH ON FRIDAY, WITH KGPI HAVING THE
BEST CHANCE (30-40 PERCENT).
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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