996
FXUS65 KMSO 091925
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
125 PM MDT WED JUL 9 2025
DISCUSSION
KEY MESSAGES:
- THUNDERSTORMS CAPABLE OF GUSTY OUTFLOW WINDS TO 50 MPH AND
LIGHTNING TODAY ACROSS LEMHI COUNTY AND SOUTHWEST MONTANA
- BREEZY AND DRY CONDITIONS TODAY, LEADING TO ELEVATED FIRE
WEATHER CONCERNS, AND CHOPPY LAKE CONDITIONS.
- COOLER, SHOWERY AND BREEZY ON THURSDAY, ESPECIALLY IN NORTHWEST
MONTANA
SHOWERS HAVE DEVELOPED JUST SOUTH OF LEMHI COUNTY BETWEEN CHALLIS
AND MACKAY. LOOKING AT MID TO LOWER SATELLITE WATER VAPOR
CHANNELS, THERE IS A SWATH OF ELEVATED MOISTURE TRACKING
NORTHEASTWARDS TOWARDS IDAHO COUNTY AND LOST TRAIL. HIGH
RESOLUTION WEATHER MODELS DEPICT CONVECTIVE INITIATION OCCURRING
BETWEEN 1 AND 2 PM MDT OVER THE SOUTHERN BITTERROOT MOUNTAINS.
TEMPERATURES ACROSS SOUTHERN RAVALLI COUNTY HAVE RISEN TO NEAR 90
DEGREES. THE DEWPOINTS NEAR 40 DEGREES F SUGGEST THAT THERE IS A
LARGE DRY LAYER AT THE SURFACE. THE PRIMARY THREAT TODAY, BESIDES
LIGHTNING, WILL BE STRONG GUSTY WINDS. THERE IS A 40 PERCENT
PROBABILITY FOR GUSTS NEAR 50 MPH FROM SALMON NORTHWARDS TO LOST
TRAIL PASS, AND UP TO 50 PERCENT CHANCE BETWEEN ANACONDA AND
BUTTE. THERE IS A 80 PERCENT CHANCE FOR LIGHTNING IN THE MOUNTAINS
OF NORTHERN LEMHI COUNTY, NORTH AND EAST TO LOST TRAIL PASS, OVER
THE ANACONDA RANGE, FLINT CREEK RANGE AND BOULDER MOUNTAINS. YOU
MAY WANT TO CONSIDER AVOIDING HIKING IN THESE RANGES THIS
AFTERNOON AND EVENING. IF THUNDER ROARS, GO INDOORS OR TO YOUR
SAFE PLACE. STAY AWAY FROM THE TALLEST OBJECT, SUCH AS A TREE. DO
NOT HUDDLE, BUT SPREAD OUT JUST IN CASE ONE PERSON IS STRUCK AND
OTHERS CAN RENDER ASSISTANCE.
GUSTY WINDS TODAY WILL BRING CHOPPY CONDITIONS ON AREA LAKES. ON
FLATHEAD LAKE, SOUTHWEST WINDS BETWEEN 15 AND 25 MPH ARE LIKELY
THIS AFTERNOON AND EVENING. AS OF 1 PM MDT, THE FLATHEAD LAKE
BIOLOGICAL STATION'S WEATHER NETWORK IS DEPICTING SOUTH WINDS
STEADY AT 18 MPH WITH GUSTS TO 23 MPH. IT MAY BE A BIT ROUGH FOR
STAND-UP PADDLEBOARDING. THERE'S A 60 PERCENT PROBABILITY FOR
GUSTS EXCEEDING 20 MPH ON THE WESTERN SHORE, AT THE NARROWS AND
ACROSS THE NORTH SHORE.
THURSDAY WILL NOT SEE AS MUCH THUNDERSTORM ACTION, BUT GLACIER
NATIONAL PARK COULD SEE A FEW ISOLATED STRIKES. THERE IS A 40
PERCENT CHANCE FOR LIGHTNING IN THE HIGHER ELEVATIONS OF THE PARK
IN THE LEWIS RANGE, INCLUDING THE GOING-TO-THE-SUN ROAD ABOVE THE
HAIRPIN TURN, OR WHAT IS CALLED THE "LOOP". ALSO THE PROBABILITIES
ARE HEIGHTENED IN THE MOUNTAINS ABOVE BOWMAN LAKE AND QUARTZ LAKE,
EAST OF POLEBRIDGE. THURSDAY WILL BE MUCH COOLER ACROSS THE
REGION, GENERALLY 10 TO 15 DEGREES COOLER IN THE VALLEYS, BUT UP
TO 20 DEGREES COOLER IN THE MOUNTAINS. TEMPERATURES WILL BE IN
THE 40S AND 50S, AND COMBINED WITH GUSTY WESTERLY WINDS TO 30 MPH
AT LOGAN PASS, IT WILL MAKE FOR A CHILLY DAY...DEFINITELY COULD
NEED A JACKET UP THERE! GUSTY WINDS 15 TO 25 MPH ARE AGAIN
POSSIBLE AT FLATHEAD LAKE ON THURSDAY.
WARM AND DRY CONDITIONS RETURN BY THE WEEKEND AS HIGH PRESSURE
REBUILDS. HIGHS WILL RETURNS TO THE 80S AND 90S, AND LOW 100S IN
THE LOWER VALLEYS OF NORTH-CENTRAL IDAHO (I.E. OROFINO, HELLS
CANYON, AND SALMON RIVER VALLEY). BREEZY WESTERLIES WILL DEVELOP
BY SUNDAY AS THE PRECURSOR EFFECTS OF A SHORTWAVE IN SOUTHERN
BRITISH COLUMBIA BEGINS TO BREAK DOWN THE RIDGE. THIS WAVE COULD
BE A LITTLE STRONGER THAN THURSDAY'S SYSTEM IN THAT IT COULD BRING
A BETTER CHANCE FOR RAIN AND STORMS, AND BRING NORTHEAST WINDS TO
THE REGION BY MONDAY. IN TERMS OF THE PROBABILITY FOR RAINFALL
OF AT LEAST 0.10" OR GREATER, THERE IS A 30 TO 40 PERCENT CHANCE
FROM EUREKA TO POLSON TO HELENA, AND 40 TO 50 PERCENT CHANCE
ACROSS GLACIER NATIONAL PARK BETWEEN MONDAY AFTERNOON AND TUESDAY
AFTERNOON. THIS COULD BE IMPORTANT FOR A LOT OF FARMERS AND
RANCHERS WHO ARE DECIDING WHETHER THEY SHOULD CUT THEIR HAY OR
NOT. THE REMAINDER OF OUR AREA HAVE MUCH LOWER CHANCES FOR
RAINFALL.
THE GENERAL TROUGHING COULD LINGER INTO WEDNESDAY, KEEPING
TEMPERATURES TEMPERED A BIT AND NEAR SEASONABLE LEVELS.
AVIATION
MORE WIDESPREAD THUNDERSTORMS ARE LIKELY LATE THIS
AFTERNOON THROUGH THE EVENING, MAINLY FROM NORTH-CENTRAL IDAHO
INTO SOUTHWEST MONTANA. OUTFLOW WINDS WILL BE A CONCERN ONCE
AGAIN, POTENTIALLY REACHING UP TO 45 KTS. BREEZY SURFACE WINDS
FROM THE WEST TO NORTHWEST WILL DEVELOP BY THIS AFTERNOON, WITH
WIDESPREAD GUSTS APPROACHING 25 KTS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR PALOUSE/HELLS
CANYON.
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