400
FXUS65 KMSO 200753
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
153 AM MDT WED MAY 20 2026
DISCUSSION
KEY MESSAGES:
- A SYSTEM DROPPING INTO CENTRAL MONTANA TODAY WILL PUSH A
BOUNDARY SOUTHWARD THROUGH WESTERN MONTANA DRIVING THUNDERSTORM
ACTIVITY THROUGH THE AFTERNOON AND INTO THE EVENING.
- DRY AND INCREASINGLY WARM CONDITIONS RETURN LATER IN THE WEEK,
TEMPERATURES NEARING 80 DEGREES(OR WARMER) BY THE WEEKEND FOR
MANY LOCATIONS.
- WATCHING MONDAY FOR POTENTIAL FIRE WEATHER CONCERNS IN
SOUTHWEST MONTANA AHEAD OF THE NEXT SYSTEM.
WESTERN MONTANA WILL SEE SHOWERS AGAIN TODAY, AS A BOUNDARY MOVES
THROUGH THE REGION THOSE SHOWERS WILL BECOME FOCUSED ALONG THE
BOUNDARY. SCATTERED THUNDERSTORMS ARE POSSIBLE ESPECIALLY AS THE
BOUNDARY PASSES, THE MAIN THREAT BEING GRAUPEL, SMALL HAIL, AND
GUSTY OUTFLOWS 25-35 MPH. TIMING ON THE BOUNDARY: AROUND NOON
KALISPELL, MT, BETWEEN 4-6PM I-90, AND 7-9PM BITTERROOT VALLEY
AND BUTTE, MT. THE HIGHEST PRECIPITATION WILL BE IN THE MOUNTAINS
AND MAINLY US-93 AND POINTS EAST TO THE CONTINENTAL DIVIDE.
A DRYING AND WARMING TREND BEGINS WEDNESDAY LASTING INTO THE
WEEKEND. IF YOU LIKE WARM AND DRY, THE WEEKEND WILL BE QUITE
PLEASANT WITH TEMPERATURES IN THE UPPER 70S AND LOW 80S. HELLS
CANYON WILL BE THE WARMEST, WHERE TEMPERATURES AROUND 90F ARE
POSSIBLE.
THE FORECAST FOR MEMORIAL DAY ONWARD STILL HAS QUESTIONS. OF
NOTE, THE NATIONAL BLEND OF MODELS, WHICH IS THE STARTING POINT OF
OUR FORECAST, NOW CLEARLY SHOWS A COOLDOWN AND INCREASE IN
PRECIPITATION CHANCES MONDAY INTO TUESDAY. SEASONAL MODELS HAVE
POINTED TO THE LAST WEEK OF MAY AS ENDING WETTER THAN NORMAL, TIME
WILL TELL.
AVIATION
A SLIGHTLY UNSTABLE WEST-NORTHWEST FLOW WILL INTERSECT
WITH A UPPER LEVEL COLD FRONT DROPPING OUT OF CANADA TODAY. WHILE
MAINLY DISORGANIZED SHOWER ACTIVITY IS EXPECTED, ALONG THAT
BOUNDARY MORE ORGANIZED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE. ANY SHOWER WILL BE CAPABLE OF GRAUPEL, SMALL HAIL, AND
ERRATIC OUTFLOW GUSTS 24 TO 33 KTS. SHOWER ACTIVITY WILL WANE NEAR
SUNSET AND PARTIAL CLEARING IS EXPECTED. AREAS THAT RECEIVE
PRECIPITATION MAY HAVE ISOLATED POCKETS OF FOG, ESPECIALLY NEAR
RIVERS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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