330
FXUS65 KMSO 261822
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1222 PM MDT MON MAY 26 2025
DISCUSSION
KEY MESSAGES:
- A COLD FRONT TODAY WILL CAUSE THUNDERSTORMS TODAY WITH A LESS
THAN 5% CHANCE OF SEVERE WEATHER, ESPECIALLY SOUTH AND EAST OF
MISSOULA.
- ANOTHER COLD FRONT IS EXPECTED ON THURSDAY WITH ANOTHER ROUND OF
THUNDERSTORMS.
- OVER 70% OF ENSEMBLES SHOW A POTENT RIDGE NEXT WEEKEND WITH MUCH
ABOVE AVERAGE BUT NOT YET RECORD WARM TEMPERATURES.
A COLD FRONT MOVING ACROSS THE REGION TODAY WILL CAUSE SOME GUSTY
WINDS IN NORTHWEST MONTANA AND SOME THUNDERSTORMS IN PORTIONS OF
WEST CENTRAL AND SOUTHWEST MONTANA. LEMHI COUNTY, ID WILL ALSO BE
AFFECTED BY THUNDERSTORMS. SATELLITE IMAGERY SHOWS SIGNIFICANT
CLOUD COVER WEST OF MISSOULA, WHICH WILL HELP LIMIT HOW MUCH THOSE
AREAS CAN WARM UP AND BECOME UNSTABLE TODAY. BUT SOUTHWEST MONTANA
HAS BEEN MOSTLY CLEAR FOR MOST OF THE DAY AND IS ABLE TO WARM UP
AND BECOME MORE UNSTABLE THIS AFTERNOON, WHICH WILL BETTER SUPPORT
THUNDERSTORM DEVELOPMENT ONCE THE FRONT COMES THROUGH. A VERY
SMALL MINORITY OF CONVECTION ALLOWING MODELS SHOW WIND GUSTS OVER
60 MPH WITH STORMS IN SOUTHWEST MONTANA THIS AFTERNOON, BUT IT'S
SO FEW MODELS THAT WE'RE STAYING WITH A LESS THAN 5% CHANCE OF
SEVERE THUNDERSTORMS THERE THIS AFTERNOON AND EVENING. SINCE MOST
OF THE CONVECTION WILL INITIATE OVER LEMHI COUNTY, WE AREN'T
EXPECTING SEVERE WEATHER THERE EITHER AS THE STORM UPDRAFTS WON'T
BE STRONG ENOUGH TO SUPPORT IT IN THE EARLY STAGES, HOWEVER, DRIER
LOW LEVELS WILL SUPPORT GUSTY WINDS TO AROUND 50 MPH NEAR SHOWERS
THERE.
ANOTHER COLD FRONT IS EXPECTED ON THURSDAY WITH SIMILAR IMPACTS.
MODEL AGREEMENT IS VERY GOOD WITH THIS SYSTEM, SO THE CONFIDENCE
IS HIGH. HOWEVER, BEFORE WE CAN DETERMINE WHICH AREAS ARE MOST
LIKELY TO SEE THUNDERSTORMS WITH THIS SYSTEM, WE'LL NEED TO GET
SOME BETTER TIMING INFORMATION SO WE CAN SEE WHAT AREAS IT WILL
MOVE THROUGH DURING THE MOST UNSTABLE TIME OF DAY, WHICH IS THE
AFTERNOON AND EVENING.
ENSEMBLES AGREE WELL ON A WARM SATURDAY WITH TEMPERATURES ABOUT 15
DEGREES ABOVE AVERAGE FOR THIS TIME OF YEAR. THEY START TO
DISAGREE ON NEXT SUNDAY WHEN A MINORITY, AROUND 30% OF THEM, BRING
IN ANOTHER TROUGH AND COLD FRONT, WHEREAS 70% OF ENSEMBLES KEEP
THE MUCH ABOVE AVERAGE HEAT GOING INTO NEXT MONDAY.
AVIATION
A COLD FRONT TODAY WILL CAUSE SOME THUNDERSTORMS TO
AFFECT AREA TERMINALS. TERMINALS KSMN AND KBTM ARE THE MOST LIKELY
TO BE EFFECTED AFTER 26/21Z AND LASTING UNTIL ABOUT 27/03Z,
ESPECIALLY FOR TERMINAL KBTM. TERMINAL KHRF HAS A SLIGHT CHANCE OF
GETTING IMPACTED BY STORMS, BUT IT'S MORE LIKELY THAT IT WILL SEE
SOME VARIABLE GUSTY WINDS FROM THE SOUTH-WEST THROUGH THE SOUTH-
EAST AND EAST DUE TO OUTFLOW FROM DEVELOPING STORMS.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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