442
FXUS65 KMSO 220749
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
149 AM MDT WED APR 22 2026
DISCUSSION
KEY MESSAGES:
- WIDESPREAD RAIN DEVELOPS TODAY, FOLLOWED BY MUCH COOLER
TEMPERATURES AND A RETURN TO WINTER DRIVING CONDITIONS OVER
MOUNTAIN PASSES BY THURSDAY.
- A POTENTIALLY IMPACTFUL BAND OF HEAVY, WET SNOW COULD DISRUPT
THE THURSDAY AND FRIDAY MORNING COMMUTES ACROSS WESTERN MONTANA
VALLEYS.
THE RIDGE OF HIGH PRESSURE THAT BROUGHT SUMMER-LIKE CONDITIONS HAS
MOVED OUT AS A STRONG LOW PRESSURE SYSTEM MOVES ONSHORE ACROSS THE
PACIFIC NORTHWEST. SCATTERED RAIN SHOWERS WILL SPREAD FROM SOUTH
TO NORTH ACROSS THE NORTHERN ROCKIES THROUGH THE DAY TODAY.
A COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE ACROSS THE
REGION THIS MORNING, BRINGING BRIEF MODERATE TO HEAVY RAIN AND
GUSTY WEST WINDS BETWEEN SUNRISE AND MID-MORNING. WIND GUSTS OF 25
TO 35 MPH ARE EXPECTED AS THE FRONT PASSES.
WIDESPREAD PRECIPITATION WILL CONTINUE THROUGH THURSDAY NIGHT. THE
HIGHEST MOISTURE AMOUNTS—WITH SOME AREAS SEEING OVER AN INCH OF
RAIN AND MELTED SNOW—ARE EXPECTED ALONG THE CLEARWATER MOUNTAINS
AND THE CONTINENTAL DIVIDE. BEHIND THE FRONT, TEMPERATURES WILL
PLUMMET 30 TO 40 DEGREES COMPARED TO TUESDAY’S HIGHS.
AS COLD AIR SETTLES OVER THE REGION, SNOW LEVELS WILL DROP RAPIDLY
TONIGHT INTO THURSDAY. BY THURSDAY MORNING, SNOW LEVELS WILL FALL
TO BETWEEN 3,000 AND 4,000 FEET. THIS WILL BRING WET, ACCUMULATING
SNOW TO HIGHER VALLEYS AND MOUNTAIN PASSES, INCLUDING LOOKOUT,
LOLO, HOMESTAKE, AND MACDONALD PASSES. TRAVELERS SHOULD PREPARE
FOR SLUSHY ROADS AND WINTER DRIVING CONDITIONS ALONG THE
CONTINENTAL DIVIDE. WINTER WEATHER ADVISORIES ARE IN EFFECT FROM 9
PM THIS EVENING THROUGH NOON FRIDAY.
WE CONTINUE TO TRACK A POTENTIAL NARROW BAND OF HEAVY
PRECIPITATION THAT COULD IMPACT THE THURSDAY MORNING COMMUTE
ACROSS NORTHWEST MONTANA. IF THIS BAND DEVELOPS OVER THE VALLEYS,
HEAVY WET SNOW WILL CAUSE LOW VISIBILITY, SLUSHY ROADS, SNAPPED
TREE BRANCHES, AND ISOLATED POWER OUTAGES. A SECOND BAND OF SNOW
MAY DEVELOP OVER WEST-CENTRAL MONTANA THURSDAY NIGHT, IMPACTING
THE FRIDAY MORNING COMMUTE. DETAILED WEATHER MODELS CONTINUE TO
SHOW THESE BANDS, LEADING TO HIGHER CONFIDENCE IN THESE IMPACTS.
THE COOL AND SHOWERY PATTERN WILL PERSIST THROUGH THE WEEKEND AS A
BROAD AREA OF LOW PRESSURE REMAINS OVER THE WESTERN UNITED STATES.
AVIATION
A COLD FRONT WILL MOVE ACROSS THE REGION THIS
MORNING AND AFTERNOON, BRINGING BRIEF MODERATE TO HEAVY RAIN AND
GUSTY WEST WINDS BETWEEN SUNRISE AND MID-MORNING. WIND GUSTS OF 25
TO 30 KTS ARE EXPECTED AS THE FRONT PASSES. THE FRONT WILL MOVE
THROUGH THE REGION BETWEEN 22/1800Z AND 22/2100Z. EXPECT MOUNTAIN
OBSCURATIONS THROUGHOUT WESTERN MONTANA AND NORTH-CENTRAL IDAHO
TODAY. SNOW-LEVELS WILL LOWER TO VALLEY FLOORS ACROSS NORTHWEST
MONTANA TOMORROW MORNING, POTENTIALLY BRING MODERATE TO HEAVY
SNOW, IMPACTING KGPI WITH ACCUMULATING SNOWFALL AND LOW
VISIBILITY. ANOTHER NARROW BAND OF MODERATE TO HEAVY PRECIPITATION
MAY BRING SNOW AND LOW VISIBILITY TO KMSO AND KHRF FRIDAY
MORNING.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT
FRIDAY FOR BITTERROOT/SAPPHIRE MOUNTAINS...BUTTE/BLACKFOOT
REGION...POTOMAC/SEELEY LAKE REGION.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 PM MDT
THURSDAY FOR WEST GLACIER REGION.
ID...WINTER WEATHER ADVISORY FROM 6 PM MDT /5 PM PDT/ THIS EVENING TO
NOON MDT /11 AM PDT/ FRIDAY FOR EASTERN LEMHI COUNTY...
SOUTHERN CLEARWATER MOUNTAINS...WESTERN LEMHI COUNTY.
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