622
FXUS65 KMSO 150655
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1255 AM MDT WED APR 15 2026
DISCUSSION
KEY MESSAGES:
- TODAY: PASS LEVEL SNOW, POTENTIAL MINOR TRAVEL IMPACTS.
- A POTENT COLD FRONT DROPS SNOW LEVELS TO THE VALLEY FLOORS TONIGHT
AND THURSDAY, BRINGING THE POTENTIAL FOR SUDDEN SNOW SQUALLS
IN SOUTHWEST MONTANA AND TRAVEL IMPACTS OVER MOUNTAIN PASSES.
- A BRIEF WARM UP WITH DRIER WEATHER IS EXPECTED FOR THE
UPCOMING WEEKEND BEFORE ACTIVE WEATHER RETURNS.
TODAY THROUGH THURSDAY:
MOISTURE CONTINUES TO STREAM OVERHEAD THIS MORNING, WITH THE HEAVIEST
PRECIPITATION FOCUSED ACROSS NORTH-CENTRAL IDAHO AND NORTHWEST MONTANA.
SNOW LEVELS CURRENTLY RANGE FROM 4,000 FEET IN NORTHWEST MONTANA TO 6,000
FEET IN LEMHI COUNTY; CONSEQUENTLY, IMPACTS WILL REMAIN PRIMARILY CONFINED
TO THE HIGHER TERRAIN. THERE IS A HIGH PROBABILITY (60-80%) THAT LOOKOUT,
MARIAS, AND LOLO PASSES WILL RECEIVE SEVERAL INCHES OF NEW SNOW.
SLICK AND SLUSHY ROADWAYS WILL REMAIN NEAR THE TO OF THE PASSES
THIS MORNING, AS AREAS JUST BELOW PASS LEVELS ARE EXPECTED TO
REMAIN MOSTLY WET.
A STRONG COLD FRONT WILL SWEEP ACROSS THE REGION THIS AFTERNOON AND
EVENING, BRINGING SUSTAINED PASS-LEVEL SNOW AND SCATTERED VALLEY
SHOWERS. THIS FRONT WILL TRIGGER A BURST OF HEAVY PRECIPITATION
AND RAPIDLY PLUNGING SNOW LEVELS, EVENTUALLY REACHING VALLEY
FLOORS.
- LOCALIZED HIGH IMPACT POTENTIAL: BE PREPARED FOR SUDDEN SNOW
SQUALLS AS THE FRONT MOVES THROUGH SOUTHWEST MONTANA THIS
EVENING. THESE SQUALLS CAN CAUSE NEAR-ZERO VISIBILITY AND
RAPIDLY CHANGING ROAD CONDITIONS. EXPECT MODERATE TRAVEL
IMPACTS ON ALL MOUNTAIN PASSES THROUGH THURSDAY MORNING.
UNCERTAINTY DETAILS:
SIGNIFICANT UNCERTAINTY REMAINS REGARDING VALLEY SNOW
ACCUMULATIONS. CURRENT MODEL GUIDANCE SHOWS THE DEEPEST MOISTURE
ARRIVING CONCURRENTLY WITH THE COLD FRONT, A SETUP THAT TYPICALLY
LIMITS ACCUMULATION IN THE VALLEYS; HOWEVER, HEAVY LOCALIZED
BURSTS REMAIN POSSIBLE. ALSO, MODELS HAVE TRENDED TOWARD A WEAK
BACKDOOR FRONT IN NORTHWEST MONTANA THURSDAY MORNING WITH AN
OUTSIDE CHANCE (20%) OF 1-2 INCHES OF SNOW FOR LOWER VALLEY
LOCATIONS SUCH AS THE FLATHEAD VALLEY.
FRIDAY THROUGH NEXT WEEK:
SHOWERY CONDITIONS WILL PERSIST THROUGH FRIDAY AS THE TROUGH
EXITS THE REGION, GRADUALLY TAPERING OFF LATE FRIDAY. A RIDGE OF
HIGH PRESSURE WILL BUILD THIS WEEKEND, PROVIDING A BRIEF BUT
WELCOME RETURN TO WARMER, DRIER WEATHER. THIS BREAK WILL BE SHORT-
LIVED, HOWEVER, AS THE NEXT WEATHER DISTURBANCE IS PROJECTED TO
ARRIVE BY EARLY NEXT WEEK.
AVIATION
MOISTURE CONTINUES TO STREAM INTO THE NORTHERN
ROCKIES TODAY, BRINGING PERIODS OF PRECIPITATION. WHILE
DOWNSLOPING WILL LIMIT INTENSITY FOR WESTERN MONTANA VALLEYS,
LIGHT RAIN IS EXPECTED AT TIMES. BREEZY SOUTHWEST WINDS WILL
INCREASE AHEAD OF THE FRONT, WITH GUSTS OF 20-30 KTS.
A STRONG COLD FRONT IS TIMED TO REACH NORTH-CENTRAL IDAHO BY
15/1900Z, MISSOULA BY 15/2300Z, AND BUTTE BY 16/0200Z. EXPECT A
WINDOW OF HEAVY PRECIPITATION AND A SHARP SHIFT TO NORTHWEST WINDS
GUSTING 30-40 KTS DURING PASSAGE. SNOW LEVELS AHEAD OF THE FRONT WILL
RANGE FROM 4000 FEET IN NORTHWEST MONTANA TO 6000 FEET IN LEMHI
COUNTY, BEHIND THE FRONT, SNOW LEVELS WILL DROP TO ALL VALLEY
FLOORS. THOUGH POST-FRONTAL MOISTURE IS LIMITED, SCATTERED SNOW
SHOWERS WILL CONTINUE ACROSS THE NORTHERN ROCKIES THROUGH
THURSDAY.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 9 AM MDT
THURSDAY FOR BUTTE/BLACKFOOT REGION...POTOMAC/SEELEY LAKE
REGION.
WINTER WEATHER ADVISORY UNTIL 9 AM MDT THURSDAY FOR LOWER CLARK
FORK REGION...WEST GLACIER REGION.
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 9 AM MDT
THURSDAY FOR BITTERROOT/SAPPHIRE MOUNTAINS.
ID...WINTER WEATHER ADVISORY FROM 6 PM MDT /5 PM PDT/ THIS EVENING TO
9 AM MDT /8 AM PDT/ THURSDAY FOR EASTERN LEMHI COUNTY...
NORTHERN CLEARWATER MOUNTAINS...SOUTHERN CLEARWATER
MOUNTAINS...WESTERN LEMHI COUNTY.
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