040
FXUS65 KMSO 211023
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
423 AM MDT THU MAY 21 2026
DISCUSSION
KEY MESSAGES:
- WARMING AND DRYING TREND EXPECTED THROUGH THE WEEKEND.
- COLD FRONT MONDAY-TUESDAY MAY USHER IN COOLER, BREEZY AND
UNSETTLED WEATHER FOR MUCH OF NEXT WEEK.
AFTER LOW CLOUDS, PATCHY FOG AND LINGERING SHOWERS DISSIPATE BY
LATER THIS MORNING, TEMPERATURES WILL RISE INTO THE 50S ACROSS
SOUTHWEST MONTANA(~10 DEGREES BELOW AVERAGE IN BUTTE), 60S ACROSS
WESTERN MONTANA AND CLOSE TO 80 DEGREES IN THE LOWER VALLEYS OF
NORTH- CENTRAL IDAHO.
TEMPERATURES WILL BE SUMMER-LIKE BY THE WEEKEND. IF YOU PLAN ON
RECREATING NEAR WATER DURING THIS TIME, BE AWARE THAT WATER
TEMPERATURES ARE QUITE COLD. PLUNGING INTO COLD WATER CAN BECOME
DANGEROUS IF YOU AREN'T PREPARED FOR IT. COLD SHOCK CAN CAUSE
DRAMATIC CHANGES IN BREATHING, HEART RATE AND BLOOD PRESSURE...AND
CAN BE LIFE-THREATENING FOR ANYONE WITHOUT PROTECTION FROM THE
TEMPERATURES OR A LIFEJACKET TO HELP YOU STAY AFLOAT. FOR MORE
INFORMATION GO TO WEATHER.GOV/SAFETY/COLDWATER
ON FRIDAY, MOISTURE EMBEDDED IN NORTHWEST FLOW COULD TRIGGER SOME
SHOWER ACTIVITY ACROSS EXTREME NORTHWEST MONTANA AND IN GLACIER
NATIONAL PARK. THERE IS ENOUGH INSTABILITY THAT AN ISOLATED
THUNDERSTORM CAN'T BE RULED OUT.
BY EARLY NEXT WEEK A TROUGH OF LOW PRESSURE WILL BRING UNSETTLED
WEATHER TO THE PACIFIC NORTHWEST AND EVENTUALLY INTO CENTRAL IDAHO
AND WESTERN MONTANA. THERE IS LARGE SPREAD IN THE WEATHER MODELS
ON THE FINER DETAILS. WHEN LOOKING AT THE ENSEMBLE CLUSTERS FOR
MONDAY, 61 PERCENT OF THE MODELS HAVE A SLOWER/MILDER SOLUTION
WHILE THE REMAINING 39 PERCENT HAVE A FASTER/COOLER/WETTER
SOLUTION. THIS TROUGH WILL CUT OFF AND MEANDER, BRINGING SHOWERY
WEATHER ALL THE WAY THROUGH MID-WEEK. IF YOU HAVE ANY OUTDOOR
PLANS DURING THE WEEK, YOU MAY WANT TO BRING RAIN GEAR JUST IN
CASE THE WETTER SOLUTIONS MATERIALIZE.
AVIATION
RAIN AND SNOW WILL TAPER OFF THIS MORNING BY
21/1400UTC OR 0800MDT ACROSS SOUTHWEST MONTANA. IFR CONDITIONS
WILL EVENTUALLY IMPROVE BY MID MORNING FOR BTM. AREAS OF FOG
ACROSS NORTHWEST MONTANA INCLUDING GPI WILL ALSO IMPROVE.
TEMPERATURES WILL REBOUND WITH MORE SUNSHINE DEVELOPING LATER
TODAY. WINDS WILL GENERALLY BE NORTHERLY AT MOST OF THE TERMINALS
EXCEPT FOR A SOUTHERLY LAKE BREEZE AT GPT. PATCHY RIVER FOG IS
POSSIBLE LATER TONIGHT INTO FRIDAY MORNING. EXPECT VFR CONDITIONS
ON FRIDAY WITH A FEW AFTERNOON SHOWERS POSSIBLE ALONG THE CANADIAN
BORDER AND INTO GLACIER NATIONAL PARK.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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