175
FXUS65 KMSO 172144
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
244 PM MST TUE FEB 17 2026
DISCUSSION
KEY MESSAGES:
- RELATIVELY DRY, WESTERLY PUSH OF ARCTIC AIR TONIGHT WILL DROP
WIND CHILLS TO BELOW ZERO ALONG AND WEST OF THE DIVIDE.
- ACCUMULATING SNOW ACROSS NORTH-CENTRAL IDAHO, SPREADING INTO
WESTERN MONTANA WEDNESDAY.
- HIGHEST PROBABILITIES FOR BELOW ZERO TEMPERATURES EXIST ALONG
AND WEST OF DIVIDE THURSDAY AND FRIDAY MORNINGS.
- QUIET WEEKEND FOLLOWED BY UNSETTLED PATTERN NEXT WEEK THAT
COULD HELP TO BUILD MORE MOUNTAIN SNOWPACK.
WE'VE RECEIVED SEVERAL IMPRESSIVE SNOWFALL REPORTS FROM NORTHWEST
MONTANA THIS AFTERNOON. UP TO 8 INCHES OF SNOW WAS REPORTED IN
HUNGRY HORSE, 5 INCHES IN EUREKA, 7.5 INCHES ON A BENCH SOUTH OF
EUREKA, AND AROUND 4 INCHES IN THE FLATHEAD VALLEY. WE EVEN
RECEIVED REPORTS OF 4 TO 5 INCHES IN THE GRANGEVILLE AREA FROM
THIS MORNING. THE STRONG LOW PRESSURE TRACKED INTO CENTRAL
MONTANA THIS AFTERNOON AND CAUSED VERY STRONG NORTHERLY WINDS
GUSTING OVER 50 MPH EAST OF THE DIVIDE. SUPPOSEDLY THE 985.2
MILLIBAR PRESSURE THAT MSO MEASURED THIS MORNING, IS THE LOWEST
PRESSURE ON RECORD FOR THE MONTH OF FEBRUARY. THE PREVIOUS RECORD
WAS 985.5 MILLIBARS SET BACK ON FEB. 1, 1963.
LATER THIS EVENING, ARCTIC AIR WILL BEGIN TO MOVE WESTWARDS ACROSS
THE CONTINENTAL DIVIDE AND SPILL INTO THE FLATHEAD VALLEY, AND
MOVE INTO THE BLACKFOOT/BUTTE REGION. THERE IS A HIGH
PROBABILITY(85%) THAT GUSTS COULD EXCEED 35 MPH THROUGH BADROCK
CANYON TO THE GLACIER PARK INTERNATIONAL AIRPORT, AND ALSO IN THE
HELMVILLE AREA TONIGHT THROUGH NOON WEDNESDAY. YOU COMBINE THE
WIND AND THE LOW TEMPERATURES REACHING THE SINGLE DIGITS IN THESE
AREAS, WIND CHILL TEMPERATURES WILL BE BELOW ZERO. IF YOU ARE
PLANNING TO TRAVEL THE US-2 CORRIDOR OR THE HIGHWAY 200 CORRIDOR
EAST OF BONNER, MAKE SURE YOU HAVE EMERGENCY GEAR IN YOUR VEHICLE,
INCLUDING EXTRA CLOTHES, HATS AND GLOVES. THE COLD AND WIND MAY
BE STRESSFUL FOR NEWBORN LIVESTOCK.
THANKS TO THE VERY COLD TEMPERATURES ALOFT WITHIN THE DEEP TROUGH
OVER THE PACIFIC NORTHWEST, THE UNSTABLE CONDITIONS ARE ALREADY
PRODUCING SNOW SHOWERS ACROSS WASHINGTON AND OREGON AND SOUTHERN
IDAHO THIS AFTERNOON. THIS ACTIVITY IS EXPECTED TO SHIFT
NORTHWARDS TOWARDS NORTH-CENTRAL IDAHO TONIGHT. HENCE, WE HAVE
HOISTED WINTER WEATHER ADVISORIES FROM IDAHO INTO WESTERN MONTANA.
THE PROBABILITIES WERE NOT VERY HIGH FOR THE MISSOULA/BITTERROOT
VALLEYS, AND TOWARDS THE SEELEY LAKE REGION. THERE WAS A QUESTION
OF HOW MUCH MOISTURE WILL BE AVAILABLE BY WEDNESDAY MORNING. THE
OTHER VALID QUESTION WAS HOW FAR WEST WAS THE ARCTIC FRONT GOING
TO MOVE BECAUSE IF YOU DON'T HAVE THE COLD AIR IN PLACE, YOU WON'T
HAVE GOOD OVERRUNNING CONDITIONS. THE LATEST 18Z RUN OF THE NAM
TRENDED A LITTLE BIT MOISTER FOR THESE AREAS, SO WILL LET THE
EVENING SHIFT REASSESS IF THOSE LOCATIONS NEED ADVISORIES OR NOT.
THERE MAY BE SOME INSTABILITY FOR THE SHORTWAVE TO TAP INTO DURING
THE DAY WEDNESDAY. THE MODELS HAVE HAD A DIFFICULT TIME
PINPOINTING WHERE THE BEST FORCING OR WHERE THE STRONGEST PART OF
THIS WAVE WILL END UP. THE LATEST 18Z HRRR DEPICTS THAT THE AREA
THAT COULD GET BETTER ENHANCEMENT MAY BE ACROSS SANDERS AND
MINERAL COUNTIES. SO THIS MEANS THERE COULD BE AN AREA THAT PICKS
UP A LITTLE BIT MORE THAN OTHER AREAS BECAUSE OF THE SNOW SHOWERS.
THE PROBABILITIES FOR SUB-ZERO LOW TEMPERATURES RANGE FROM 30 TO
40 PERCENT IN THE FLATHEAD VALLEY TO EUREKA, BUT ARE MUCH HIGHER,
CLOSER TO 90 PERCENT FOR POLEBRIDGE, MARIAS PASS, AND IN THE HIGH
VALLEYS WEST OF THE DIVIDE IN POWELL COUNTY ON THURSDAY MORNING.
OTHER THAN THE COLD TEMPERATURES, THERE COULD BE PERSISTENT LIGHT
SNOW SHOWERS THROUGH FRIDAY.
A RIDGE WILL BUILD OVER THE WEEKEND, SO THE CHANCE FOR SNOW WILL
BE DECREASED.
AS FOR NEXT WEEK, THE ENSEMBLE CLUSTERS DEPICT ANOTHER DEEP TROUGH
IMPACTING THE WESTERN U.S. EARLY NEXT WEEK. THE NBM IS BRINGING IN
LIKELY CHANCE FOR PRECIPITATION BY MONDAY AND TUESDAY ACROSS OUR
REGION WITH HIGHER SNOW LEVELS(3500 TO 4500 FEET). THIS COULD
MEAN A CHANCE FOR MIXED PRECIPITATION IN THE VALLEYS, BUT MOUNTAIN
SNOWFALL.
AVIATION
A BROAD TROUGH OVER THE REGION AND COLD FRONT THIS
MORNING HAVE BROUGHT QUITE A LOT OF MOISTURE AND SNOW TO THE
BOUNDARY LAYER. A SHORTWAVE RIDGE AT THE 700MB LEVEL HAS HELPED TO
SUPPRESS FURTHER SHOWERS THIS AFTERNOON. AN ARCTIC AIR MASS EAST
OF THE CONTINENTAL DIVIDE WILL SEEP THROUGH AREA PASSES LATE
TONIGHT, STARTING AROUND 18/08Z. AS THE SHORTWAVE RIDGE FADES AND
THE COOLER AIR POOLS IN THE VALLEYS OF WESTERN MONTANA, UP-SLOPE
FLOW ACROSS THE MOUNTAINS OF CENTRAL IDAHO WILL GENERATE ENOUGH
LIFT TO PRODUCE LIGHT SNOW SHOWERS. WITH THE BROAD UPPER LEVEL
TROUGH REMAINING IN PLACE, THE 700MB SHORTWAVE RIDGE MOVING OUT OF
THE REGION, AND A VERY MOIST BOUNDARY LAYER, AND SOME LIFT WITH
THE UP-SLOPE FLOW, WE HAVE ALL THE INGREDIENTS FOR MODERATE TO
HEAVY SNOW SHOWERS ACROSS THE REGION TOMORROW. HIGH RESOLUTION
ENSEMBLES ARE PREDICTING TIMING FOR SHOWERS TO START UP AROUND
18/19Z. THESE SHOWERS WILL MOVE ALONG QUICKLY AND CAUSE BRIEF
PERIODS OF MODERATE TO HEAVY SNOW. TERMINALS KHRF, KMSO, KSMN, AND
KBTM ARE MOST LIKELY TO BE DIRECTLY IMPACTED BY SHOWERS. WATCH FOR
MORE SNOW IMPACTS AT AREA TERMINALS IN THE NEXT FEW TAFS
ISSUED.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY FROM 3 AM TO 5 PM MST WEDNESDAY FOR
KOOTENAI/CABINET REGION.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THURSDAY FOR WEST GLACIER
REGION.
WINTER WEATHER ADVISORY FROM 2 AM TO 5 PM MST WEDNESDAY FOR
FLATHEAD/MISSION VALLEYS.
WINTER WEATHER ADVISORY FROM 1 AM TO 11 PM MST WEDNESDAY FOR
LOWER CLARK FORK REGION.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM MST
WEDNESDAY FOR BITTERROOT/SAPPHIRE MOUNTAINS.
ID...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM PST
WEDNESDAY FOR NORTHERN CLEARWATER MOUNTAINS.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM PST
WEDNESDAY FOR SOUTHERN CLEARWATER MOUNTAINS.
WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST
WEDNESDAY FOR OROFINO/GRANGEVILLE REGION.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 8 AM PST
THURSDAY FOR LOWER HELLS CANYON/SALMON RIVER REGION.
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