881
FXUS65 KMSO 152035
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
235 PM MDT FRI MAY 15 2026
DISCUSSION
KEY MESSAGES:
- UNSETTLED, COOL, AND SHOWERY CONDITIONS PERSIST INTO THE
WEEKEND.
- MOUNTAIN SNOW THIS WEEKEND WILL CREATE DIFFICULT CONDITIONS FOR
BACKCOUNTRY RECREATION, ESPECIALLY ALONG THE CONTINENTAL
DIVIDE.
- WIDESPREAD FROST AND FREEZING TEMPERATURES ARE HIGHLY LIKELY
SUNDAY THROUGH TUESDAY MORNINGS.
SHOWERY CONDITIONS HAVE DEVELOPED THIS AFTERNOON UNDER MODEST
INSTABILITY AND MOISTURE AHEAD OF AN APPROACHING TROUGH. SHOWERS
WILL MAINLY FAVOR THE HIGHER TERRAIN ACROSS NORTHWEST MONTANA. SNOW
LEVELS WILL CONTINUE TO HOVER AROUND 5,000-6,000 FEET, SO LIGHT
SNOW ACCUMULATIONS WILL REMAIN CONFINED TO THE HIGHER TERRAIN.
A MORE ORGANIZED LOW PRESSURE SYSTEM WILL BEGIN TO DROP INTO
WESTERN MONTANA AND NORTH CENTRAL IDAHO THIS WEEKEND, BRINGING
INCREASED CHANCES FOR PRECIPITATION AREA WIDE. THE SYSTEM HAS
ANOMALOUSLY COLD AIR ASSOCIATED WITH IT, AND WILL DROP SNOW
LEVELS AS LOW AS 4000 FEET BY SUNDAY MORNING. ACCUMULATING SNOW IS
ANTICIPATED FOR THE HIGHER ELEVATIONS, BRINGING DIFFICULT
CONDITIONS FOR BACKCOUNTRY RECREATION DUE TO SLUSHY SNOW
ACCUMULATIONS ON UNPAVED ROADWAYS. COLD, WET AND BREEZY CONDITIONS
WILL INCREASE THE HYPOTHERMIA RISK FOR ANY RECREATIONALISTS. THE
PRECIPITATION LOOKS TO INTENSIFY ALONG THE CONTINENTAL DIVIDE ON
SUNDAY AS NORTHEASTERLY FLOW ENHANCES LIFT ALONG THE CONTINENTAL
DIVIDE. ACCUMULATING SLUSHY SNOW EVEN INTO THE HIGHER ELEVATION
VALLEYS IN SOUTHWEST MONTANA (BUTTE) IS POSSIBLE. WINTER WEATHER
ADVISORIES HAVE BEEN ISSUED FOR THE HIGHER TERRAIN AND MAY NEED TO
BE EXPANDED WESTWARDS ON FUTURE SHIFTS.
UNSEASONABLY COLD TEMPERATURES WILL BE IN PLACE SUNDAY THROUGH
EARLY NEXT WEEK, BRINGING THE THREAT FOR A FROST/FREEZE ACROSS
MANY VALLEYS OF WESTERN MONTANA AND NORTH CENTRAL IDAHO. THOSE
WITH SENSITIVE VEGETATION OR EARLY SEASON PLANTINGS MAY WANT TO
TAKE PROTECTIVE MEASURES, ESPECIALLY ON MONDAY MORNING WHEN FROST
HAS THE POTENTIAL TO BE MOST WIDESPREAD DUE TO DECREASED CLOUD
COVER.
A GENERAL WARMING TREND IS ANTICIPATED NEXT WEEK, THOUGH GENERALLY
RETURNING TO NORMAL FOR THIS TIME OF YEAR. A PERIOD OF BRIEF
DRYING IS POSSIBLE BUT MAY NOT BE LONG LASTING.
AVIATION
WEST WINDS OF ABOUT 10 TO 20 KNOTS WILL BE WIDESPREAD
THIS AFTERNOON AHEAD OF A TROUGH OF LOW PRESSURE APPROACHING FROM
THE WEST. SCATTERED SHOWERS AT KMSO AND KGPI MAY BRING BRIEF,
LOCALIZED REDUCTIONS IN VISIBILITY INTO THIS EVENING. MORE
WIDESPREAD SHOWERS WILL ARRIVE OVERNIGHT TONIGHT OR EARLY SATURDAY
MORNING, FAVORING KGPI, KMSO, AND KHRF. EXPECT WIDESPREAD LOWERED
CEILINGS DOWN TO ABOUT 2500 FEET BY SATURDAY MORNING, AS WELL AS
CONTINUED PRECIPITATION THROUGH ABOUT MIDDAY TRANSITIONING TO
SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON. PRECIPITATION
WILL OBSCURE TERRAIN THROUGHOUT THE NORTHERN ROCKIES AIRSPACE.
MSO WATCHES/WARNINGS/ADVISORIES
MT...WINTER WEATHER ADVISORY FROM MIDNIGHT SATURDAY NIGHT TO MIDNIGHT
MDT SUNDAY NIGHT FOR BITTERROOT/SAPPHIRE MOUNTAINS...
BUTTE/BLACKFOOT REGION...POTOMAC/SEELEY LAKE REGION...WEST
GLACIER REGION.
ID...NONE.
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