034
FXUS65 KMSO 021654
AFDMSO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
1054 AM MDT WED JUL 2 2025
UPDATE
INCREASED POPS AND CHANCES FOR LIGHTNING THIS EVENING
INTO TONIGHT ACROSS WESTERN MONTANA. ADDED DRY LIGHTING TO THE
FORECAST TONIGHT ACROSS WEST-CENTRAL MONTANA AND NORTH-CENTRAL
IDAHO.
DISCUSSION
KEY MESSAGES:
- STRONG TO ISOLATED SEVERE THUNDERSTORMS TODAY MAINLY ACROSS
WEST CENTRAL MONTANA, SOUTHWEST MONTANA, AND LEMHI COUNTY, IDAHO
- A TROUGH FRIDAY AND SATURDAY WILL BRING THUNDERSTORMS AND
POTENTIALLY HEAVY RAIN TO PORTIONS OF SOUTHWEST AND WEST CENTRAL
MONTANA.
- LONG RANGE ENSEMBLES ARE SHOWING POTENTIAL FOR AN EXTENDED HOT,
DRY PERIOD THROUGH MID JULY.
RADAR IMAGERY THIS MORNING SHOWS A LINE OF SHOWERS EAST OF THE
US-93 CORRIDOR MOVING EASTWARD TOWARDS THE DIVIDE, WITH PLENTY OF
CLEARING ON GOES SATELLITE IMAGERY ACROSS NORTH-CENTRAL IDAHO.
THIS AREA OF CLEARING WILL ALLOW FOR TEMPERATURES TO QUICKLY WARM
THROUGH THIS EARLY AFTERNOON. AS TEMPERATURES WARM, THE ATMOSPHERE
WILL QUICKLY DESTABILIZE, WITH FORECAST SOUNDINGS HIGHLIGHTING
MLCAPE OF 300-700 J/KG BY 5PM MDT THIS EVENING. AS PREVIOUSLY
DISCUSSED, AN APPROACHING TROUGH WILL PROVIDE PLENTY OF SYNOPTIC
ASCENT FOR SHOWERS AND THUNDERSTORMS, WITH RECENT MODEL RUNS
SUGGESTING CONVECTIVE INITIATION BETWEEN 1-3PM MDT ACROSS LEMHI
COUNTY AND SOUTHWEST MONTANA, BEFORE STORMS MOVE NORTHWARD ACROSS
WEST-CENTRAL MONTANA BETWEEN 4-7PM MDT. DISCRETE STORMS WILL FORM
INITIALLY, EVOLVING INTO LINEAR SEGMENTS AS WIND SHEAR INCREASES
TOWARDS 30-35KTS THIS EVENING. THE LAST TWO RUNS OF THE HREF HAS
POINTED TOWARDS HIGH PROBABILITIES (70-90%) FOR STRONG OUTFLOW
WINDS ACROSS THE BITTERROOT VALLEY AND POINTS EAST ALONG THE I-90
CORRIDOR TOWARDS THE DIVIDE. THIS MATCHES UP WELL STATISTICAL
MODELS AND FORECAST SOUNDINGS, THEREFORE OUR CONFIDENCE IS HIGHER
THAN NORMAL FOR THESE STORMS TO OCCUR AND PRODUCE GUSTY OUTFLOW
WINDS, WITH ISOLATED GUSTS EXCEEDING 60 MPH WITH THE STRONGEST
UPDRAFTS.
CONVECTION WILL CONTINUE INTO TONIGHT AND EARLY THURSDAY MORNING,
WITH ADDITIONAL ROUNDS OF STORMS ACROSS CENTRAL IDAHO INTO WEST-
CENTRAL MONTANA. VERTICAL PROFILES SUGGEST INSTABILITY AND
MOISTURE WILL REMAIN ELEVATED, INCREASING THE RISK FOR DRY
THUNDERSTORMS.
AVIATION
AN APPROACHING TROUGH WILL KICK OFF ANOTHER ROUND OF
THUNDERSTORMS AGAIN TODAY. TERMINALS KSMN, KHRF, AND KBTM ARE THE
MOST LIKELY TO BE AFFECTED BY STRONG TO ISOLATED SEVERE STORMS.
THE HREF IS ALSO SHOWING THE CONVECTION CONTINUING INTO THE NIGHT
OVER TERMINAL KMSO, THOUGH SEVERE STORMS ARE NOT EXPECTED THERE.
WHILE TERMINAL KGPI WILL MISS OUT ON MOST OF THE CONVECTION TODAY,
SOME HREF MEMBERS ARE SHOWING A MARGINALLY SEVERE STORM MOVING
THROUGH THERE OVER NIGHT. OVERALL, IT'S GOING TO BE A BUSY
AFTERNOON WITH THUNDERSTORMS INITIATING BY 02/1900-2100Z NEAR
KBTM AND KHRF, WITH ACTIVITY IMPACTING KMSO AROUND
02/2300-03/0300Z.
PREV DISCUSSION
/ISSUED 158 AM MDT WED JUL 2 2025/
DISCUSSION...
KEY MESSAGES:
- POTENTIALLY SEVERE THUNDERSTORMS TODAY MAINLY ACROSS WEST
CENTRAL MONTANA, SOUTHWEST MONTANA, AND LEMHI COUNTY, IDAHO.
- A TROUGH FRIDAY AND SATURDAY WILL BRING THUNDERSTORMS AND
POTENTIALLY HEAVY RAIN TO PORTIONS OF SOUTHWEST AND WEST CENTRAL
MONTANA.
- LONG RANGE ENSEMBLES ARE SHOWING POTENTIAL FOR AN EXTENDED HOT,
DRY PERIOD THROUGH MID JULY.
ANOTHER ROUND OF THUNDERSTORMS TODAY WILL START IN LEMHI COUNTY,
IDAHO AND MOVE NORTHEAST. SOME STORMS MAY BE SEVERE, WITH
CONVECTION ALLOWING MODELS SHOWING POTENTIAL WIND GUSTS OVER 60
MPH. CURRENT MODEL RUNS SHOW THE BEST POTENTIAL FOR STRONG WINDS
IN THE SOUTHERN BITTERROOT VALLEY. WITH A TROUGH APPROACHING THE
REGION, THERE WILL BE MORE SHEAR TODAY THAN YESTERDAY. THIS MEANS
THERE IS POTENTIAL FOR MORE HAIL, AND LARGER HAIL. IT'S
INTERESTING TO NOTE THAT EVEN THOUGH DYNAMIC MODELS ARE SHOWING
THE POTENTIAL FOR SEVERE STORMS, MACHINE LEARNING MODELS KEEP THE
AREA OF SEVERE STORMS FARTHER EAST. SO OVERALL, IT'S MARGINAL FOR
SEVERE IMPACTS WITH A 5% OR LESS CHANCE OF BEING DIRECTLY AFFECTED
BY SEVERE WEATHER.
A TROUGH MOVING OUT OF THE SOUTHWEST FRIDAY AND THIS WEEKEND WILL
BRING ANOTHER ROUND OF THUNDERSTORMS. THIS TIME THOUGH IT WILL
BRING SOME MOISTURE FROM THE SOUTHWEST MONSOON, AND HEAVY RAIN IS
POSSIBLE WITH ANY STORMS. ENSEMBLES HAVE BEEN CONSISTENT WITH
KEEPING THE HEAVY RAIN LEMHI COUNTY, IDAHO, THE SOUTHERN
BITTERROOT VALLEY, THE SAPPHIRE MOUNTAINS AND AREAS EASTWARD TO
THE CONTINENTAL DIVIDE. HEAVY RAIN ON RECENT BURN SCARS IS A MAJOR
CONCERN AND THIS SYSTEM IS WELL ALIGNED WITH THE DAVY FIRE FROM
LAST YEAR WHICH WOULD DIRECTLY IMPACT SKALKAHO SUMMIT NEAR THE
FALLS.
IN THE LONGER TERM, ENSEMBLES HAVE SHOWING THE POTENTIAL FOR A
HOT, DRY RIDGE LASTING FROM ABOUT JULY 90TH THROUGH THE 14TH.
HOWEVER, IT'S NOTABLE THAT WHILE AI ENSEMBLES SHOW A SIMILAR
PATTERN, THEY AREN'T AS INTENSE WITH THE RIDGE OR THE HEAT. ANY
WAY YOU LOOK AT IT, THE PREPONDERANCE OF MODELS POINT TO AN
EXTENDED DRY PERIOD OF A WEEK OR MORE COMING UP.
AVIATION...AN APPROACHING TROUGH WILL KICK OFF ANOTHER ROUND OF
THUNDERSTORMS AGAIN TODAY. TERMINALS KSMN, KHRF, AND KBTM ARE THE
MOST LIKELY TO BE AFFECTED WITH POTENTIALLY SEVERE STORMS. THE
HREF IS ALSO SHOWING THE CONVECTION CONTINUING INTO THE NIGHT OVER
TERMINAL KMSO, THOUGH SEVERE STORMS ARE NOT EXPECTED THERE. WHILE
TERMINAL KGPI WILL MISS OUT ON MOST OF THE CONVECTION TODAY, SOME
HREF MEMBERS ARE SHOWING A MARGINALLY SEVERE STORM MOVING THROUGH
THERE OVER NIGHT. OVERALL, IT'S GOING TO BE A BUSY AFTERNOON WITH
THUNDERSTORMS AND IT MAY CONTINUE INTO THE EVENING OR OVERNIGHT
HOURS AT KMSO AND KGPI.
MSO WATCHES/WARNINGS/ADVISORIES
MT...NONE.
ID...NONE.
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