043
FXUS65 KMSO 131849
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1249 PM MDT MON APR 13 2026
DISCUSSION
KEY MESSAGES:
- TODAY: SCATTERED SHOWERS AND POTENTIAL FOR A THUNDERSTORM ALONG
THE CANADIAN BORDER.
- WEDNESDAY: PASS LEVEL SNOW, POTENTIAL TRAVEL IMPACTS.
- WEDNESDAY NIGHT/THURSDAY: STRONG COLD FRONT WITH SNOW LEVELS
TO VALLEY FLOORS BUT LIGHT VALLEY ACCUMULATIONS. MODERATE PASS
LEVEL TRAVEL IMPACTS CONTINUE.
THE LOW PRESSURE SYSTEM WILL CONTINUE TO EXIT THE REGION THIS
AFTERNOON AND EVENING THE MAJORITY OF THE NORTHERN ROCKIES ARE
EXPECTED TO RECEIVE SCATTERED SHOWERS WITH THE BEST POTENTIAL FOR
THUNDERSTORMS BEING ACROSS NORTHWEST MONTANA, ESPECIALLY ALONG THE
CANADIAN BORDER. THE SHOWER ACTIVITY WILL DIMINISH DURING THE
OVERNIGHT HOURS.
THE NEXT FETCH OF MOISTURE WILL START TO MAKE ITS WAY INTO THE
NORTHERN ROCKIES TUESDAY AFTERNOON INTO WEDNESDAY AHEAD OF THE
NEXT LOW PRESSURE SYSTEM. THE BULK OF THE PRECIPITATION IS
EXPECTED ACROSS NORTH CENTRAL IDAHO INTO NORTHWEST MONTANA. SNOW
LEVELS WILL BE HOVERING AROUND 4500 FEET, SO ANY IMPACTS FROM
SNOW, WHICH SHOULD BE MINIMAL, WILL BE MAINLY CONFINED TO THE
HIGHER TERRAIN. LOOKOUT, MARIAS AND LOLO PASSES COULD EXPERIENCE A
COUPLE OF INCHES OF NEW SNOW, BUT ACCUMULATIONS ON ROADWAYS BE
FAIRLY LIMITED.
A STRONG COLD FRONT ASSOCIATED WITH THE NEXT LOW PRESSURE SYSTEM
WILL PUSH THROUGH THE NORTHERN ROCKIES WEDNESDAY AFTERNOON AND
EVENING. THIS FRONT WILL ENHANCE THE PRECIPITATION AND CAUSE SNOW
LEVELS TO DROP FAIRLY QUICKLY. THE LATEST MODEL RUNS INDICATE THAT
THE BULK OF THE PRECIPITATION WILL BE ASSOCIATED WITH THE FRONT.
THE FRONT COULD ALSO CAUSE SNOW SQUALL CONDITIONS AS IT MOVES
THROUGH SOUTHWEST MONTANA DURING WEDNESDAY EVENING. SNOW ON
MOUNTAIN PASSES COULD CREATE MODERATE TRAVEL IMPACTS BY THURSDAY
MORNING. THE BETTER DYNAMICS ASSOCIATED WITH A PROLONGED SNOW
EVENT APPEARS TO BE NORTH OF THE FORECAST AREA, BUT SOME WRAP
AROUND PRECIPITATION COULD IMPACT GLACIER NATIONAL PARK ON
THURSDAY. MODEL GUIDANCE IS LEANING MORE TOWARDS WIDESPREAD SHOWER
ACTIVITY ACROSS THE REGION ON THURSDAY. THE VALLEYS SHOULD
ANTICIPATE SNOWFALL FROM THE SHOWERS, BUT ACCUMULATIONS WILL BE
FAIRLY MINIMAL. THE HIGHER ELEVATIONS COULD RECEIVE SOME
ADDITIONAL SNOW ACCUMULATIONS BY FRIDAY MORNING.
A RIDGE OF HIGH PRESSURE SLIDES OVER THE REGION THIS WEEKEND
CAUSING A WARMING AND DRYING TREND, BUT IT WILL BE SHORT LIVED AS
ANOTHER DISTURBANCE IS EXPECTED BY THE FIRST PART OF NEXT WEEK.
AVIATION
SATELLITE IMAGERY SHOWS AN UPPER LEVEL LOW MOVING
SOUTHWARD TOWARDS CENTRAL IDAHO THIS AFTERNOON. CLOUDS AND SHOWER
ACTIVITY CONTINUE TO WRAP AROUND THIS LOW TO THE NORTH AND WEST,
WITH RAIN SHOWERS FOCUSED IN IDAHO AND NORTHWEST MONTANA. THE
ATMOSPHERE WILL CONTINUE TO DESTABILIZE THROUGH EARLY EVENING,
WITH A 10-20 PERCENT CHANCE OF ISOLATED THUNDERSTORMS IN
NORTHWEST MONTANA NEAR THE US/CANADA BORDER. SHOWER ACTIVITY WILL
DECREASE THIS EVENING, ENDING FOR MOST AREAS AFTER 14/0600Z AS THE
LOW DEPARTS THE REGION.
CEILINGS/VISIBILITY: AREAS OF MVFR CEILINGS AND VISIBILITY WILL
CONTINUE UNDER SHOWER ACTIVITY THROUGH THIS EVENING. LOWER
CEILINGS WILL FOCUS ALONG THE ID/MT BORDER AND IN NORTHWEST
MONTANA.
SURFACE WINDS: WEST-SOUTHWEST WINDS WILL CONTINUE THROUGH
14/0000-02000Z THIS EVENING, SUSTAINED NEAR 10-15 KTS. WINDS ARE
FORECAST TO DIMINISH SIGNIFICANTLY AFTER SUNSET AS THE BOUNDARY
LAYER STABILIZES.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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