098
FXUS65 KMSO 281854
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1254 PM MDT FRI AUG 28 2026
DISCUSSION
KEY MESSAGES:
- ISOLATED THUNDERSTORMS ACROSS SOUTHWEST MONTANA AND LEMHI COUNTY
THIS EVENING. MORE WIDESPREAD SHOWERS AND THUNDERSTORMS
SATURDAY.
- TEMPERATURES COOLING THROUGH THE WEEKEND, RUNNING 10 DEGREES
BELOW NORMAL BY SUNDAY
THE NORTHERN ROCKIES REMAINS SANDWICHED BETWEEN A BROAD LOW
PRESSURE SYSTEM OVER BRITISH COLUMBIA AND HIGH PRESSURE CENTERED
OVER THE FOUR CORNERS REGION. THE END RESULT IS SOUTHWEST FLOW
ALOFT OVER WESTERN MONTANA AND NORTH CENTRAL IDAHO. ANOTHER PULSE
OF ENERGY IS EXPECTED TO MOVE THROUGH THE FLOW THIS AFTERNOON AND
EVENING PRODUCING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS SOUTHWEST MONTANA AND LEMHI COUNTY. THE MAIN STORM THREATS
WILL BE GUSTY OUTFLOW WINDS TO 40 MPH AND LIGHTNING. THE REST OF
THE AREA WILL LARGELY REMAIN DRY THROUGH THIS EVENING, THOUGH
BREEZY SOUTHWEST TO WEST WINDS WILL DEVELOP.
BEGINNING TONIGHT INTO SATURDAY, THE LOW PRESSURE SYSTEM OVER
CANADA WILL STRETCH SOUTHWARDS AND CLOSE OFF OVER WASHINGTON.
SHOWERS AND ISOLATED THUNDERSTORMS WILL DEVELOP LATE TONIGHT, AND
BECOME MORE WIDESPREAD THROUGH THE DAY SATURDAY. BY SATURDAY
AFTERNOON, A COLD FRONT WILL MOVE THROUGH THE REGION, WHICH COULD
HELP STRENGTHEN A FEW STORMS, MAINLY ALONG AND SOUTH OF HIGHWAY
12. CHANCES FOR WETTING RAINS (MORE THAN 0.10") REACHES 80 TO 90
PERCENT FOR WEST-CENTRAL AND SOUTHWEST MONTANA, AS WELL AS LEMHI
COUNTY. CONFIDENCE FOR WETTING RAIN DECREASES ACROSS NORTHWEST
MONTANA, WHERE PROBABILITIES FOR WETTING RAINS DROP BELOW 30
PERCENT.
BY SUNDAY, TEMPERATURES WILL DROP INTO THE UPPER 60S TO LOW 70 FOR
MANY VALLEY LOCATIONS, WHICH IS ROUGHLY 10 DEGREES BELOW NORMAL
FOR THIS TIME OF YEAR. BREEZY CONDITIONS WILL CONTINUE, THOUGHT
HIGHER HUMIDITIES AND COOLER TEMPERATURES WILL KEEP THE FIRE
WEATHER THREAT LOW.
BRIEF HIGH PRESSURE REBOUNDS MONDAY AND TUESDAY, WHICH WILL ALLOW
TEMPERATURES TO WARM ONCE AGAIN INTO THE 80S. THIS LOOKS SHORT
LIVED HOWEVER AS NUMEROUS FORECAST MODELS ARE SHOWING THE
POTENTIAL FOR A COLDER AND POTENTIALLY WETTER LOW PRESSURE SYSTEM
MID TO LATE NEXT WEEK.
AVIATION
SHOWERS AND THUNDERSTORMS WILL AGAIN BE A CONCERN FOR
KSMN AND KBTM THIS AFTERNOON AND EVENING, MAINLY BETWEEN 28/2200Z
AND 29/0200Z. STORMS WILL BE CAPABLE OF GUSTY WINDS TO ABOUT
30-35 KNOTS AND FREQUENT LIGHTNING. THE REMAINDER OF THE NORTHERN
ROCKIES WILL SEE MOSTLY VFR CONDITIONS WITH WESTERLY OR
SOUTHWESTERLY GUSTS TO ABOUT 20 KNOTS IN THE AFTERNOON AHEAD OF AN
APPROACHING TROUGH OF LOW PRESSURE. EXPECT INCREASING CLOUDS
OVERNIGHT WITH WIDESPREAD RAIN STARTING ON SATURDAY MORNING.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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