006
FXUS65 KBOI 262011
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
211 PM MDT SAT SEP 26 2026
KEY MESSAGES
- MOSTLY CLOUDY AND SLIGHTLY WARMER SUNDAY AND MONDAY,
THE MOSTLY CLEAR BUT CONTINUED WARMING THROUGH THE WEEK.
- A SLIGHT CHANCE OF SHOWERS AND AFTERNOON THUNDERSTORMS IN
SOUTHEAST OREGON AND CENTRAL IDAHO ON SUNDAY.
SHORT TERM /THROUGH MONDAY NIGHT/
YESTERDAY'S COLD FRONT MOVED RAPIDLY EASTWARD ACROSS OUR CWA BUT GOT
ONLY AS FAR SOUTH AS NORTHERN NEVADA WHERE IT HAS BECOME STATIONARY.
FROM THERE THE FRONTAL ZONE WILL NOW MOVE SLOWLY NORTHWARD AGAIN AS
A DIFFUSE WARM FRONT TONIGHT THROUGH SUNDAY UNDER SOUTHWESTERLY FLOW
ALOFT AHEAD OF THE NEXT INCOMING PACIFIC UPPER TROUGH. MIDDLE AND
HIGH CLOUDS WILL INCREASE FROM SOUTH TO NORTH TONIGHT AND LEAD TO A
10-20 PERCENT CHANCE OF SHOWERS ON SUNDAY. THERE WILL ALSO BE JUST
ENOUGH INSTABILITY FOR A SLIGHT (10%) CHANCE OF THUNDERSTORMS IN
THE CENTRAL IDAHO MOUNTAINS SUNDAY AFTERNOON AND EARLY EVENING.
THE INCOMING UPPER TROUGH WILL BECOME A CLOSED LOW IN NEVADA BY
MONDAY AND TAKE THE FRONTAL ZONE BACK OUT OF OUR AREA, RESULTING
IN CLEARING SKIES IN OREGON MONDAY AND IN IDAHO MONDAY NIGHT.
GRADUAL WARMING IS EXPECTED THROUGH TUESDAY, DUE TO CLOUDS AND
THE WARM FRONT TONIGHT AND SUNDAY, AND THE DEPARTURE OF THE COOL
UPPER LOW INTO NEVADA ON MONDAY. NO SIGNIFICANT WINDS THROUGH
THE PERIOD.
LONG TERM /TUESDAY THROUGH SATURDAY/
GFS AND ECM CONTINUE THE DRY AND WARMING TREND THROUGH THURSDAY
BUT AFTER THAT THE GFS BRINGS ANOTHER COLD FRONT AND SUPPORTING
UPPER TROUGH INLAND FROM THE NORTH PACIFIC, WHILE ECM CONTINUES
THE WARMING AND DRYING TREND WITH ONLY A WEAK COLD FRONT ARRIVING
ON SUNDAY. NBM, ON WHICH OUR FORECAST IS BASED, FOLLOWS THE ECM
SOLUTION MORE CLOSELY BUT HOLDS BACK ON THE AMOUNT OF WARMING
WEDNESDAY AND THURSDAY WHEN THE GFS AND ECM ARE STILL IN GOOD
AGREEMENT. SO WE WOULD EXPECT LATER NBM FORECASTS TO BE WARMER
ON THOSE DAYS, BUT FOR NOW WE'LL STAY WITH TEMPS ONLY ABOUT 5
DEGREES ABOVE NORMAL.
AVIATION /18Z SATURDAY THROUGH SUNDAY/
ISSUED 1141 AM MDT SAT SEP 26 2026
VFR WITH BKN-OVC HIGH CLOUD COVERAGE THIS EVENING THROUGH EARLY
SUNDAY. SURFACE WINDS: NE-NW 5-12 KT THIS AFTERNOON. WINDS
ALOFT AT 10KFT MSL:
SW 10-25 KT.
KBOI...VFR WITH BKN HIGH CLOUDS. SURFACE WINDS: W-NW UP TO 10
KT.
SUNDAY OUTLOOK...VFR WITH DENSE MID-HIGH LEVEL CLOUD COVERAGE.
ISOLATED RAIN SHOWERS, MAINLY OVER SE OREGON AND CENTRAL ID
MOUNTAINS IN THE MORNING THROUGH EVENING. UP TO A 10% CHANCE OF
AFTERNOON LIGHTNING STRIKES OVER HIGH TERRAIN AREAS. SURFACE
WINDS: VARIABLE UP TO 10 KT IN THE MORNING, BECOMING SW-NW 5-15
KT WITH GUSTS TO 15-20 KT IN THE AFTERNOON.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...LC
LONG TERM....LC
AVIATION.....JY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page