619
FXUS65 KMSO 161728
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1128 AM MDT FRI OCT 16 2026
DISCUSSION
KEY MESSAGES:
- GUSTY WINDS ON SATURDAY CREATING CHOPPY CONDITIONS FOR AREA
LAKES, ESPECIALLY ACROSS NORTHWEST MONTANA.
- COOLER AND SHOWERY BY EARLY TO MID NEXT WEEK.
HIGH PRESSURE CONDITIONS CONTINUE THROUGH TOMORROW CREATING STABLE
CONDITIONS. WHAT DOES THAT PRODUCE IN TERMS OF WEATHER, VALLEY
INVERSIONS, LIGHT WINDS, LIMITED AFTERNOON WARMING, AND COLD
MORNINGS WITH PATCHY FREEZING FOG AND LOW STRATUS.
BY SATURDAY AFTERNOON, OUR VALLEY INVERSIONS BREAK AND
TEMPERATURES WARM INTO THE LOWER 60S WESTERN MT AND UPPER 60S LOW
70S IN NORTH-CENTRAL ID. A DRY COLD FRONT WILL APPROACH FROM THE
WEST PUSHED BY STRONG MID-LEVEL WINDS. AS THE ATMOSPHERE
DESTABILIZES THOSE WINDS WILL TRANSLATE DOWN INTO VALLEYS. EXPECT
WINDS 15 TO 25 MPH IN VALLEYS WITH SOME LOCATIONS IN NORTHWEST MT
SEEING GUSTS TO 35 MPH, WHILE MOUNTAINS RECEIVE GUSTS 35 TO 45
MPH. FOR THIS REASON, WE HAVE ISSUED A LAKE WIND ADVISORY FOR
THOSE WANTING TO ENJOY ONE POTENTIALLY LAST TASTE OF SUMMER. WINDS
WILL CREATE CHOPPY CONDITIONS ON AREA LAKES AFTER 2 PM, SO PLAN
ACCORDINGLY.
HIGH PRESSURE TEMPORARILY REBUILDS ON SUNDAY WITH A RETURN TO
STABLE CONDITIONS. EXPECT LIGHT WINDS, COOL MORNINGS WITH PATCHY
FOG, AND AFTERNOON TEMPERATURES THAT DO NOT QUITE HIT FULL
POTENTIAL.
THE MODELS KEEP THE NORTHERN ROCKIES 'IN BETWEEN' OR WHAT WE CALL
SPLIT FLOW. THE POLAR JET STREAM REMAINS WELL NORTH IN CANADA,
WHILE AN AREA OF LOW PRESSURE IS EXPECTED TO CLOSE OFF OVER
CALIFORNIA. LIGHT SHOWERS, COOL TEMPERATURES, AND BREEZY
AFTERNOONS ARE EXPECTED, WITH NO MAJOR SYSTEMS CURRENTLY. IF THAT
LOW PRESSURE OVER CALIFORNIA EJECTS MORE NORTHEASTERLY THAN THE
CURRENT FORECAST, A MORE EXCITING FORECAST MAY RESULT.
AVIATION
HIGH PRESSURE REMAINS OVER WESTERN MONTANA AND NORTH
CENTRAL IDAHO THROUGH SATURDAY MORNING. VFR CONDITIONS WILL
DOMINATE THE AIRSPACE. HOWEVER, VALLEY FOG MAY DEVELOP ONCE AGAIN
IN LOWER RIVER VALLEYS, ESPECIALLY NEAR KGPI. FOG MAY BECOME
DENSE FOR A FEW HOURS THIS MORNING NEAR THIS AIRFIELD BETWEEN
17/1100Z AND 17/1600Z. AN EASTERLY GRADIENT DEVELOPS AROUND
MIDNIGHT, I-90 AND SOUTH, AND MAY MITIGATE FOG DEVELOPMENT. A
COLD FRONT WILL MOVE THROUGH THE REGION LATER SATURDAY BRINGING
INCREASED MID LEVEL CLOUD COVER, AND MORE NOTABLY, GUSTY WESTERLY
WINDS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...LAKE WIND ADVISORY FROM 2 PM TO 7 PM MDT SATURDAY FOR
FLATHEAD/MISSION VALLEYS.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page