440
FXUS65 KMSO 181051
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
351 AM MST MON NOV 18 2024
DISCUSSION
KEY MESSAGES:
- SHOWERY CONDITIONS THROUGH TUESDAY.
- MOIST SOUTHWEST FLOW SETTING UP BY THURSDAY.
THE NORTHERN ROCKIES WILL BE UNDER A BROAD TROUGH OF LOW PRESSURE
FOR THE NEXT COUPLE DAYS AFTER THE PASSAGE OF THE COLD FRONT LAST
NIGHT. THIS TROUGH WILL KEEP TEMPERATURES NEAR SEASONAL AVERAGE
ALONG WITH SCATTERED SNOW SHOWERS AS SNOW LEVELS WILL REMAIN
AROUND 1500 FEET OR LOWER.
THE UPPER LEVEL FLOW WILL BECOME SOUTHWESTERLY BY WEDNESDAY INTO
THURSDAY WHICH WILL ALLOW FOR A WEAK ATMOSPHERIC RIVER TO STREAM
INTO THE NORTHERN ROCKIES. THIS AR WILL BRING SIGNIFICANT MOISTURE
TO THE HIGHER TERRAIN, ESPECIALLY ALONG THE MONTANA/IDAHO BORDER.
SNOW LEVELS WILL BE RISING TO AROUND 4500 FEET BY THURSDAY
MORNING. THIS FLOW PATTERN APPEARS TO LINGER OVER THE REGION INTO
SATURDAY ALLOWING THE MOUNTAINS TO RECEIVE AN ADDITION 1 TO 2 FEET
OF NEW SNOW, WHILE THE VALLEYS MAINLY EXPERIENCE RAIN.
THE MODELS ARE STILL STRUGGLING ON HOW TO BRING IN THE NEXT TROUGH
OF LOW PRESSURE INTO THE WESTERN UNITED STATES. THE PATH OF THE
LOW WILL BE THE DETERMINING FACTOR ON HOW MUCH COLD AIR GETS DRAWN
OVER THE CONTINENTAL DIVIDE. THE LATEST MODEL CLUSTERS ARE SHOWING
AROUND A 35% CHANCE OF THE COLD AIR BEING PULLED INTO WESTERN
MONTANA BY SATURDAY. WHILE THE REMAINDER PRIMARILY KEEP THE COLDER
AIR EAST OF THE DIVIDE.
AVIATION
THE COLD FRONT HAS MOVED THROUGH THE NORTHERN ROCKIES
LAST NIGHT. A BROAD TROUGH OF LOW PRESSURE WILL BE OVER THE REGION
CAUSING SCATTERED TO NUMEROUS SHOWERS. THE MAIN PRECIPITATION TYPE
WILL BE SNOW AS SNOW LEVELS WILL BE 1500 FEET OR LOWER. THESE SNOW
SHOWERS WILL CAUSE PERIODIC REDUCED VISIBILITY AT THE TERMINALS
ALONG WITH OBSCURED MOUNTAINS AND PASSES.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR
BITTERROOT/SAPPHIRE MOUNTAINS...BUTTE/BLACKFOOT REGION...
KOOTENAI/CABINET REGION...LOWER CLARK FORK REGION...WEST
GLACIER REGION.
ID...WINTER WEATHER ADVISORY UNTIL 11 AM MST /10 AM PST/ THIS MORNING
FOR EASTERN LEMHI COUNTY...NORTHERN CLEARWATER MOUNTAINS...
SOUTHERN CLEARWATER MOUNTAINS...WESTERN LEMHI COUNTY.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page