017
FXUS65 KMSO 170847
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
247 AM MDT FRI APR 17 2026
DISCUSSION
KEY MESSAGES:
- SHOWERS CONTINUE AGAIN TODAY.
- WARMER, MORE MILD WEATHER FOR THIS WEEKEND AND EARLY NEXT WEEK.
- ACTIVE WEATHER RETURNS MID NEXT WEEK.
THE CLOSED UPPER LEVEL LOW THAT BROUGHT MUCH COOLER TEMPERATURES
TO THE REGION HAS MOVED EAST OF THE CONTINENTAL DIVIDE. IT'S LEFT
THE REGION IN SLIGHTLY CYCLONIC, NORTHWEST FLOW WITH COLD AIR
ALOFT AGAIN TODAY. THAT MEANS WHEN THE SUN COMES UP AND WARMS
THINGS UP AT THE SURFACE, CONDITIONS WILL BECOME UNSTABLE. THE
SLIGHTLY CYCLONIC FLOW MEANS THE ATMOSPHERE AT LARGE WON'T DO
ANYTHING TO SUPPRESS THE CONVECTION THAT RESULTS, AND THE RESULT
IS ANOTHER ROUND OF SHOWERS TODAY. TEMPERATURES WILL TREND ABOUT 8
DEGREES WARMER THAN YESTERDAY, SO MANY VALLEY LOCATIONS THAT HAD
SNOW SHOWERS YESTERDAY WILL HAVE RAIN SHOWERS OR MIXED RAIN AND
SNOW SHOWERS TODAY AND NO ACCUMULATION ON THE ROADS IS EXPECTED.
THIS EVENING A RIDGE BUILDS IN OVER THE REGION AND WILL LAST
THROUGH EARLY NEXT WEEK. THIS WILL CAUSE MILD WEATHER AND WARMER
TEMPERATURES. FOR MONDAY AND TUESDAY, THE VALLEYS OF WESTERN
MONTANA WILL REACH INTO THE 70S, WITH SOME LOCATIONS LIKE
MISSOULA, THE BITTERROOT VALLEY, AND LIBBY GETTING INTO THE UPPER
70S. IN CENTRAL IDAHO, MANY LOWER ELEVATION LOCATIONS WILL RISE
INTO THE LOW 80S EARLY NEXT WEEK.
ENSEMBLE FORECASTS ARE IN VERY GOOD AGREEMENT FOR A CUT-OFF LOW
PRESSURE SYSTEM TO MOVE ASHORE IN NORTHERN CALIFORNIA AND OREGON
AROUND WEDNESDAY. THAT SYSTEM WILL PUSH SOME MOISTURE AND
INSTABILITY INTO OUR REGION, AND WE EXPECT THUNDERSTORMS ACROSS
THE REGION MID TO LATE NEXT WEEK. ONCE THE SYSTEM COMES ASHORE,
ENSEMBLES DIVERGE ON HOW IT EVOLVES, SO THERE IS LITTLE WE CAN SAY
ABOUT HOW LONG IT WILL IMPACT THE REGION AND HOW MUCH OF A COOL
DOWN IT WILL BRING WITH IT.
AVIATION
EXPECT ANOTHER ROUND OF CONVECTION STARTING LATE THIS
MORNING AND LASTING INTO THE EVENING. RISING HEIGHTS TODAY AS A
RIDGE BUILDS IN WILL CAP OFF THE SHOWERS EARLIER IN THE EVENING
THAN RECENT DAYS, AND ANY IMPACTS AT AREA TERMINALS WILL BE
INTERMITTENT. A RIDGE STARTS TO BUILD TONIGHT AND WE EXPECT VFR
CONDITIONS OVER THE WEEKEND AND EARLY NEXT WEEK.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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