740
FXUS65 KMSO 301900
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
100 PM MDT TUE JUN 30 2026
DISCUSSION
KEY MESSAGES:
- SCATTERED SHOWERS AND THUNDERSTORMS ARE ONGOING THIS AFTERNOON
AND INTO TONIGHT.
- EXPECT DAILY SHOWERS AND THUNDERSTORMS FOR THE REST OF THE
WEEK.
- DAYTIME HIGH TEMPERATURES INCREASE THROUGH THE UPCOMING HOLIDAY
WEEKEND.
SATELLITE IMAGERY EARLY THIS AFTERNOON INDICATES A CLOSED LOW
PRESSURE SYSTEM SPINNING OVER SOUTH-CENTRAL CANADA. TO THE WEST,
ANOTHER TROUGH OVER SOUTHEAST ALASKA IS ACCELERATING NORTHWESTERLY
UPPER LEVEL FLOW AGAINST A BROAD TROUGH OF HIGH PRESSURE OFF THE
COAST OF CALIFORNIA. THE TROUGH TO THE EAST IS DEPARTING AFTER
DELIVERING A HEALTHY DOSE OF SUMMERTIME SNOW AND RAIN TO THE
NORTHERN ROCKIES. LOW PRESSURE AND RESIDUAL MOISTURE FROM THE
DEPARTING SYSTEM WILL RESULT IN CONTINUING SHOWERS AND
THUNDERSTORMS THIS AFTERNOON, AND AGAIN ON WEDNESDAY AFTERNOON.
MODEL SOUNDINGS INDICATE WEAK INSTABILITY AND SHEAR ALONG WITH
SLIGHTLY-ABOVE-AVERAGE PRECIPITABLE WATER, BRINGING GARDEN
VARIETY THUNDERSTORMS TODAY (THINK PEA SIZE HAIL, BRIEF HEAVY
RAIN, GUSTY OUTFLOW WINDS OF ABOUT 30 MPH, LIGHTNING). INSTABILITY
AND SHEAR INCREASE ON WEDNESDAY AS A SHORTWAVE TROUGH MOVES
THROUGH THE NORTHERN ROCKIES, ALLOWING FOR SOME SLIGHTLY STRONGER,
ALBEIT SUB-SEVERE, THUNDERSTORMS IN THE AFTERNOON. THE FOCUS FOR
CONVECTION WILL BE PRIMARILY ACROSS NORTH-CENTRAL IDAHO, SOUTHWEST
MONTANA, AND ALONG THE CONTINENTAL DIVIDE.
AS THE WEEK DEVELOPS, UPPER LEVEL FLOW BECOMES WESTERLY AND
TEMPERATURES BECOME SEASONABLE BY FRIDAY. THERE WILL BE ENOUGH
MOISTURE AND INSTABILITY TO NOT RULE OUT AFTERNOON THUNDERSTORMS.
BY THE HOLIDAY WEEKEND, TEMPERATURES WILL BE SLIGHTLY ABOVE
NORMAL, MID TO UPPER 80S IN THE VALLEYS OF WESTERN MONTANA, 90S
IN THE LOWER SALMON AND CLEARWATER VALLEYS OF IDAHO.
AVIATION
LINGERING SHOWERS REMAIN OVER NORTHWEST MONTANA
INCLUDING KGPI THIS AFTERNOON. ELSEWHERE, MOSTLY CLOUDY SKIES ARE
WHAT REMAINS FROM A RATHER STORMY WEEKEND. HIGH RESOLUTIONS MODELS
INDICATE A ROUND OF THUNDERSTORMS MOVING SOUTHWEST TO NORTHEAST
THROUGH NORTH-CENTRAL IDAHO AND ACROSS THE BITTERROOT AND MISSOULA
VALLEYS THIS EVENING. STORMS WILL MOVE OUT BY ABOUT MIDNIGHT.
THREATS ASSOCIATED WITH THESE STORMS WILL BE BRIEF HEAVY RAIN,
SMALL HAIL, LIGHTNING, AND GUSTY OUTFLOW WINDS TO ABOUT 25 KNOTS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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