644
FXUS65 KMSO 211052
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
352 AM MST WED JAN 21 2026
DISCUSSION
KEY MESSAGES:
- STRONG VALLEY INVERSIONS WILL PERSIST FOR A COUPLE MORE DAYS
- COLDER TEMPERATURES ON THE WAY AND BREAK UP OF THE LOW STRATUS
DECK FRIDAY INTO SATURDAY
- UNCERTAINTY IN THE FORECAST FOR NEXT WEEK
NOT MUCH WILL CHANGE IN THE FORECAST FOR TODAY THROUGH THURSDAY AS
STRONG VALLEY INVERSIONS WILL REMAIN IN PLACE ALONG WITH LOW
STRATUS ACROSS NORTH CENTRAL IDAHO INTO NORTHWEST MONTANA.
THURSDAY NIGHT A MODIFIED ARCTIC AIR MASS WILL BEGIN TO INFILTRATE
THE WESTERN MONTANA CAUSING SOME EASTERLY WINDS. THIS PUSH OF
COLDER AIR IS NOT EXPECTED TO BE OVERLY STRONG BUT ENOUGH EASTERLY
WINDS SHOULD HELP TO SCOUR OUT THE LOW STRATUS DECK THAT HAS BEEN
ENTRENCH ACROSS NORTHWEST MONTANA. THE COLD AIR ALONG WITH
CLEARING SKIES WILL CAUSE TEMPERATURES TO BE RATHER COOL BY FRIDAY
MORNING WITH THE MAJORITY OF WESTERN MONTANA BEING IN THE SINGLE
DIGITS. THE STRATUS DECK OVER NORTH CENTRAL IDAHO APPEARS TO HOLD
ON UNTIL SOME TIME ON FRIDAY ONCE THE EASTERLY WINDS CAN MAKE IT
PASSED THE MONTANA/IDAHO BORDER. FRIDAY AND SATURDAY APPEARS TO BE
THE COLDEST TIMEFRAME DURING THE FORECAST PERIOD. THE MODELS
CONTINUE TO SHOW THAT THIS FRONT WILL BE STARVED OF ANY
SIGNIFICANT MOISTURE SO ANY SHOWER ACTIVITY WILL BE EXTREMELY
LIGHT AND MAINLY CONFINED TO THE CONTINENTAL DIVIDE.
THE MODELS ARE ABOUT 50/50 ON A WEEK DISTURBANCE MOVING THROUGH
THE NORTHERN ROCKIES MONDAY INTO TUESDAY. CURRENT GUIDANCE IS ONLY
GIVING AROUND A 40% CHANCE OF AN INCH OF SNOW IN THE MOUNTAINS.
THE FAR MAJORITY OF THE MODELS SHOW THE RIDGE OF HIGH PRESSURE
BUILDING OVER THE REGION BY WEDNESDAY CAUSING STRONG INVERSIONS TO
REDEVELOP WITH THE THREAT OF FOG AND/OR LOW STRATUS.
AVIATION
SOUNDING LIKE A BROKEN RECORD HERE WITH LOW STRATUS
AND FOG IMPACTING THE MAJORITY OF NORTH CENTRAL IDAHO INTO
NORTHWEST MONTANA FOR THE NEXT 24 HOURS, MAINLY IMPACTING KGPI.
KMSO COULD EXPERIENCE SOME VICINITY FOG DURING THE MORNING HOURS.
WHILE THE REMAINDER OF THE TERMINALS SHOULD HAVE FAIR FLYING
CONDITIONS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page