139
FXUS65 KMSO 171843
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1243 PM MDT SAT OCT 17 2026
DISCUSSION
KEY MESSAGES:
- GUSTY WINDS TODAY (SATURDAY), CREATING CHOPPY CONDITIONS FOR
AREA LAKES, ESPECIALLY ACROSS NORTHWEST MONTANA.
- MILD TEMPERATURES NEXT WEEK, WITH SHOWER CHANCES FOR MOST AREAS
BY THURSDAY AND FRIDAY.
- CONFIDENCE IS GROWING FOR COOLER TEMPERATURES BY NEXT WEEKEND.
A COLD FRONT AND UPPER-LEVEL WEATHER SYSTEM ARE MOVING ACROSS THE NORTHERN
ROCKIES THIS AFTERNOON. OTHER THAN A FEW LIGHT SHOWERS ALONG THE CANADIAN
BORDER, THIS FRONT IS MOSTLY PRODUCING GUSTY WEST TO SOUTHWEST WINDS ACROSS
WESTERN MONTANA AND NORTH-CENTRAL IDAHO. THE STRONGEST WINDS ARE STILL
EXPECTED TO BE ACROSS NORTHWEST MONTANA THIS AFTERNOON AND EVENING, WHERE
GUSTS BETWEEN 25 AND 35 MPH WILL BE QUITE COMMON. ANYONE PLANNING TO BE ON
AREA LAKES, ESPECIALLY FLATHEAD LAKE, SHOULD BE AWARE OF CHOPPY CONDITIONS
AND PERSISTENT WINDS. A LAKE WIND ADVISORY WILL REMAIN IN PLACE FROM 2:00
PM TO 7:00 PM.
WEATHER MODELS REMAIN IN STRONG AGREEMENT FOR A SPLIT WEATHER PATTERN
SUNDAY INTO EARLY NEXT WEEK. THIS PATTERN WILL BE CHARACTERIZED BY A LOW
PRESSURE SYSTEM DIVING SOUTH ALONG THE WEST COAST AND SETTLING ALONG THE
CENTRAL CALIFORNIA COAST, WHILE A BROAD LOW PRESSURE SYSTEM AND THE JET
STREAM REMAIN POSITIONED IN ALASKA AND NORTHWEST CANADA. THIS PATTERN WILL
PROVIDE MILD FALL TEMPERATURES, WITH WARM AFTERNOONS AND COLDER MORNING
TEMPERATURES, ALONG WITH LIGHT WINDS. ISOLATED SHOWERS RETURN TO THE
FORECAST ACROSS LEMHI COUNTY, ID AND SOUTHWEST MONTANA BY TUESDAY AND
WEDNESDAY AS MOISTURE BEGINS TO STREAM NORTHWARD FROM THE LOW NEAR
CALIFORNIA.
FORECAST UNCERTAINTY BEGINS TO INCREASE THURSDAY INTO FRIDAY. WEATHER
MODELS SUGGEST THE CANADIAN SYSTEM WILL BEGIN TO DIP SOUTHWARD AND
POTENTIALLY MERGE WITH THE LOW OVER CALIFORNIA AS IT BEGINS TO LIFT
NORTHWARD. THE EXACT TIMING OF THESE SYSTEMS MERGING REMAINS THE LARGEST
QUESTION MARK. AROUND HALF OF THE WEATHER MODELS BRING WIDESPREAD SHOWER
ACTIVITY ACROSS THE NORTHERN ROCKIES BY THURSDAY, WHILE THE REMAINING
MODELS SUGGEST ACTIVITY FOCUSED FURTHER SOUTH. BY FRIDAY INTO SATURDAY,
AROUND 90% OF THE MODELS SUGGEST A LOW PRESSURE SYSTEM WILL PASS THROUGH,
WITH CHANCES OF PRECIPITATION INCREASING ALONG WITH COLDER
TEMPERATURES.
AVIATION
A COLD FRONT AND ASSOCIATED WEATHER SYSTEM ARE MOVING ACROSS
THE NORTHERN ROCKIES THIS AFTERNOON. OTHER THAN A FEW LIGHT SHOWERS ALONG
THE CANADIAN BORDER, THIS FRONT IS MOSTLY PRODUCING GUSTY WEST TO SOUTHWEST
WINDS ACROSS WESTERN MONTANA AND NORTH-CENTRAL IDAHO. THE STRONGER WINDS
WILL BE ACROSS NORTHWEST MONTANA, WHERE SUSTAINED WINDS OF 15 KNOTS WITH
GUSTS OF 25 TO 30 KNOTS ARE EXPECTED BETWEEN 17/2000Z AND 17/0100Z. WIND
GUSTS WILL BE ELEVATED ELSEWHERE ACROSS THE REGION, THOUGH THEY WILL BE
LOWER, AT AROUND 20 TO 25 KNOTS. WINDS GUSTING 45 TO 55 KNOTS AT THE RIDGE
TOPS ACROSS THE ENTIRE REGION MAY CREATE A BUMPY RIDE IN AND AROUND AREA
TERMINALS. ASIDE FROM THAT, BROKEN TO OVERCAST SKIES CAN BE EXPECTED FOR
MOST OF THE AFTERNOON AS HIGH-LEVEL CLOUDS ASSOCIATED WITH THIS SYSTEM PASS
OVERHEAD.
MSO WATCHES/WARNINGS/ADVISORIES
MT...LAKE WIND ADVISORY UNTIL 7 PM MDT THIS EVENING FOR
FLATHEAD/MISSION VALLEYS.
ID...NONE.
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