150
FXUS65 KMSO 231929
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
129 PM MDT THU APR 23 2026
DISCUSSION
KEY MESSAGES:
- SNOW SHOWERS TODAY AND TONIGHT WILL BE HEAVY AT TIMES.
- NEAR RECORD OR RECORD COLD TEMPERATURES FORECAST FOR SATURDAY
MORNING.
- COLD LASTS INTO EARLY NEXT WEEK.
A BROAD, COLD CLOSED LOW OVER CENTRAL CANADA THIS MORNING IS
CAUSING A COLD, NORTHWEST FLOW ACROSS THE NORTHERN ROCKIES AND
HELPING TO PUSH A COLD FRONT ACROSS THE REGION. THIS IS A VERY
COLD AIR MASS, AND AS IT INTERACTS WITH THE WARMER AND VERY MOIST
AIR MASS CURRENTLY OVER THE REGION, IT IS CAUSING SOME HEAVY SNOW
SHOWERS. MTDOT WEB CAMERAS TODAY HAVE SHOWN WHITEOUT CONDITIONS AT
TIMES ON SOME OF THE ROADS IN NORTHWESTERN MONTANA. MINIMAL SNOW
ACCUMULATIONS ARE EXPECTED IN THE VALLEYS TODAY DUE TO WARM GROUND
TEMPERATURES AND THE WARMING EFFECTS OF THE DAYTIME SUN. MOUNTAIN
LOCATIONS, HOWEVER, WILL CONTINUE TO SEE ACCUMULATING SNOW,
ESPECIALLY ON UNPAVED ROADS. THAT ALL CHANGES THIS EVENING WHEN WE
LOSE THE SUNLIGHT AND THE COLD AIR PUSHES FURTHER SOUTH, WITH
EVEN VALLEY LOCATIONS POTENTIALLY PICKING UP SOME SNOW BY FRIDAY
MORNING. THIS IS MAINLY A CONCERN IN AREAS WHERE THE LEAVES HAVE
COME OUT ON THE TREES, SINCE THE LEAVES WILL HOLD ONTO THE SNOW
AND CAUSE TREE LIMBS TO BREAK, POTENTIALLY CAUSING POWER OUTAGES.
ANOTHER POTENTIAL HAZARD IS SNOW MELTING ON THE WARM GROUND AND
THEN REFREEZING INTO ICE OVERNIGHT AS THE AIR TEMPERATURE
CONTINUES TO DROP. ANY ICE FORMATION THIS WAY WOULD BE PATCHY, AND
DIFFICULT TO SPOT, SO IF TRAVELING THIS EVENING OR OVERNIGHT USE
CAUTION AND BE ON THE LOOKOUT FOR ICE.
AFTER THE COLD AIR MOVES INTO THE REGION, MODELS ARE CURRENTLY
FORECASTING RECORD LOWS FOR SATURDAY AND SUNDAY MORNING IN
MISSOULA, AND NEAR RECORD LOWS FOR CENTRAL IDAHO INCLUDING AREAS
LIKE RIGGINS AND OROFINO. THE MISSOULA AND BITTERROOT VALLEYS ARE
EXPECTED TO DROP INTO THE LOW 20S AND TEENS FOR MORNING
TEMPERATURES THIS WEEKEND. WE'VE RECENTLY BEEN AS COLD AS THE
MID-20S, SO WHILE A FREEZE SHOULDN'T BE TOO MUCH OF A SHOCK, THIS
WILL BE A VERY HARD FREEZE AND HAS THE POTENTIAL TO DAMAGE FRUIT
TREES THAT HAVE STARTED TO BUD OR BLOOM. ALSO, FOR ANY AREAS THAT
HAVE STARTED IRRIGATION ALREADY THIS YEAR, A FREEZE THIS HARD MAY
DAMAGE EQUIPMENT. TEMPERATURES WILL TREND WARMER EACH MORNING, BUT
WE DO NOT EXPECT THEM TO RETURN TO AVERAGE MORNING TEMPERATURES
UNTIL TUESDAY OR WEDNESDAY OF NEXT WEEK, SO THE COLD WILL LAST A
FEW DAYS AT LEAST.
AVIATION
A BROAD, VERY COLD UPPER LEVEL TROUGH OVER THE
NORTHERN ROCKIES IS CAUSING WIDESPREAD CONVECTION TODAY THAT WILL
LAST THROUGH THE NIGHT. WITH COLDER AIR MOVING INTO THE REGION,
PRECIPITATION HAS TURNED TO SNOW ALREADY AT TERMINALS KGPI, KMSO,
AND KBTM. WE EXPECT IT WILL TURN TO SNOW AT KHRF THIS EVENING AND
EARLY TOMORROW MORNING AT KSMN. DUE TO THE HIGH SOLAR ANGLE AND
WARM GROUND TEMPERATURES, SNOW ACCUMULATION IS NOT EXPECTED ON
PAVED SURFACES UNTIL TONIGHT, THOUGH IT WILL VARY BY TERMINAL AND
WILL START ACCUMULATING FIRST AT KBTM THIS EVENING. THIS AIR MASS
IS VERY UNSTABLE, AND DESPITE THE COLD TEMPERATURES OCCASIONAL
LIGHTNING HAS BEEN OBSERVED. VISIBILITY AND CEILING RESTRICTIONS
WILL LAST HALF AN HOUR TO ABOUT 3 HOURS AS SHOWERS MOVE THROUGH.
SNOW MELTING ON THE PAVEMENT DUE TO THE WARM GROUND THIS EVENING
COULD REFREEZE AND BECOME BLACK ICE AS THE TEMPERATURES DROP
TONIGHT.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY UNTIL NOON MDT FRIDAY FOR
BITTERROOT/SAPPHIRE MOUNTAINS...BUTTE/BLACKFOOT REGION...
POTOMAC/SEELEY LAKE REGION.
WINTER WEATHER ADVISORY UNTIL 6 PM MDT THIS EVENING FOR WEST
GLACIER REGION.
ID...WINTER WEATHER ADVISORY UNTIL NOON MDT /11 AM PDT/ FRIDAY FOR
EASTERN LEMHI COUNTY...SOUTHERN CLEARWATER MOUNTAINS...
WESTERN LEMHI COUNTY.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page