875
FXUS65 KMSO 060722
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
122 AM MDT SAT JUN 6 2026
DISCUSSION
KEY MESSAGES:
- SCATTERED SHOWERS, ISOLATED THUNDERSTORMS, AND COOLER
TEMPERATURES THIS WEEKEND.
- FROST POTENTIAL SUNDAY MORNING, MORE WIDESPREAD ON MONDAY
MORNING.
- INCREASING POTENTIAL FOR WIDESPREAD PRECIPITATION BY TUESDAY
AND WEDNESDAY NEXT WEEK WITH A CLOSED LOW PRESSURE SYSTEM.
AN UPPER-LEVEL TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST
TODAY, GRADUALLY PUSHING A COLD FRONT THROUGH THE NORTHERN
ROCKIES. DAYTIME TEMPERATURES WILL BE ROUGHLY 10 DEGREES COOLER
THAN YESTERDAY. WHILE MID-LEVEL MOISTURE WILL STREAM OVERHEAD,
OVERALL DYNAMIC FORCING AND INSTABILITY REMAIN LIMITED.
IMPACTS (TODAY THROUGH SUNDAY):
* THUNDERSTORMS: HIGH- RESOLUTION MODEL GUIDANCE SUPPORTS A
20-30% CHANCE OF THUNDERSTORMS ACROSS SOUTHWEST MONTANA THIS
AFTERNOON.
* WINDS: A WESTERLY GRADIENT WILL GENERATE AFTERNOON GUSTS OF 15-25
MPH, WITH LOCALIZED GUSTS UP TO 40 MPH POSSIBLE NEAR ANY
THUNDERSTORM ACTIVITY IN SOUTHWEST MONTANA. WATCH FOR LOCALIZED
ELEVATED FIRE WEATHER CONCERNS THIS AFTERNOON IN SOUTHWEST
MONTANA.
* PRECIPITATION & SNOW: SHOWERS WILL FOCUS IN NORTHWEST MONTANA
AND ALONG THE DIVIDE TODAY, THEN SOUTH OF THE I-90 CORRIDOR
TONIGHT THROUGH SUNDAY MORNING. AS THE UPPER TROUGH PASSES
OVERHEAD ON SUNDAY, ADDITIONAL SCATTERED INSTABILITY SHOWERS
WILL DEVELOP. TOTAL PRECIPITATION LOOKS LIGHT, THOUGH MINOR SNOW
ACCUMULATIONS OF 1-2 INCHES ARE POSSIBLE ABOVE 5,000 FEET.
* TEMPERATURES: HIGHS ON SUNDAY WILL DROP 10-15 DEGREES BELOW
NORMAL. COMBINED WITH AFTERNOON WIND GUSTS OF 15-25 MPH, CONDITIONS
WILL FEEL UNSEASONABLY CHILLY.
FROST POTENTIAL (SUNDAY AND MONDAY MORNINGS):
DRIER AIR AND CLEARING SKIES WILL INTRODUCE FROST CONCERNS FOR
SENSITIVE VEGETATION.
* SUNDAY MORNING: PATCHY FROST IS POSSIBLE WITHIN THE VALLEYS OF
NORTHWEST MONTANA.
* MONDAY MORNING: A MORE WIDESPREAD FROST EVENT IS ANTICIPATED FOR
THE LOWER VALLEYS OF WESTERN MONTANA AND THE HIGHER VALLEYS OF
NORTH-CENTRAL IDAHO.
MID-TO-LATE NEXT WEEK OUTLOOK:
ENSEMBLE GUIDANCE IS IN EXCELLENT AGREEMENT REGARDING A LARGE,
POTENT WEATHER SYSTEM ARRIVING BY MID-WEEK, BRINGING THE POTENTIAL
FOR SIGNIFICANT, WIDESPREAD PRECIPITATION ACROSS WESTERN MONTANA
AND NORTH-CENTRAL IDAHO.
AHEAD OF THIS SYSTEM, THUNDERSTORM ACTIVITY IS EXPECTED TO BECOME
MORE NUMEROUS ACROSS THE REGION, PARTICULARLY BY TUESDAY. MOST
LOCATIONS HAVE A DECENT PROBABILITY (50-70% CHANCE) OF RECEIVING
OVER HALF AN INCH OF RAIN BETWEEN TUESDAY AND THURSDAY.
WHILE LESS LIKELY, THERE IS A 10-20% CHANCE OF THIS SYSTEM
TAPPING INTO DEEPER, SUBTROPICAL MOISTURE. THIS SCENARIO COULD
DELIVER 1-2+ INCHES OF RAIN ALONG THE CONTINENTAL DIVIDE. IF THESE
HEAVIER AMOUNTS MATERIALIZE, LOCALIZED FLOODING WILL BECOME A
CONCERN, ESPECIALLY IN RECENTLY SATURATED BASINS SUCH AS THE
MISSION MOUNTAINS AND SURROUNDING VALLEYS.
AVIATION
AN UPPER-LEVEL TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST TODAY,
GRADUALLY PUSHING A COLD FRONT THROUGH THE NORTHERN ROCKIES.
WHILE MID-LEVEL MOISTURE STREAMS OVERHEAD, LIMITED DYNAMIC FORCING
AND WEAK INSTABILITY WILL KEEP THE MAJORITY OF REGIONAL
PRECIPITATION RESTRICTED TO SCATTERED LIGHT SHOWERS. VFR
CONDITIONS WILL GENERALLY PREVAIL AT TERMINALS, THOUGH OCCASIONAL
MOUNTAIN OBSCURATIONS CAN BE EXPECTED DUE TO LOWERING CLOUD BASES,
PARTICULARLY ACROSS NORTHWEST MONTANA AND ALONG THE CONTINENTAL
DIVIDE. HIGH- RESOLUTION GUIDANCE SUPPORTS A 20% TO 30% CHANCE OF
THUNDERSTORM DEVELOPMENT IN SOUTHWEST MONTANA THIS AFTERNOON,
PRIMARILY BETWEEN 20Z AND 02Z.
A TIGHTENING WESTERLY GRADIENT WILL SUPPORT SUSTAINED SURFACE
WINDS OF 10 TO 15 KNOTS WITH AFTERNOON GUSTS REACHING 15 TO 25
KNOTS. LOCALIZED, ERRATIC GUSTS UP TO 35 KNOTS WILL BE POSSIBLE IN
THE VICINITY OF ANY AFTERNOON THUNDERSTORMS IN SOUTHWEST MONTANA.
SURFACE WINDS ARE FORECAST TO DIMINISH AND DECOUPLE WITHIN THE
VALLEYS BY LATE EVENING, BUT THEY WILL REMAIN ELEVATED ALONG
REGIONAL RIDGETOPS OVERNIGHT. THIS WILL MAINTAIN A RISK FOR
LOCALIZED MECHANICAL TURBULENCE OVER HIGH TERRAIN THROUGH SUNDAY
MORNING. MEANWHILE, ONGOING LIGHT SHOWER ACTIVITY WILL TRANSITION
TO AREAS PRIMARILY ALONG AND SOUTH OF THE I-90 CORRIDOR OVERNIGHT
INTO SUNDAY MORNING.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page