textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Strong thunderstorms capable of wind gusts to 60 mph, blowing dust, small hail, and brief heavy rain possible today, with the highest potential across southeast Oregon and west-central Idaho.

- Breezy southeast winds today with gusts 30 to 40 mph across southeast Oregon and Idaho south of Boise.

- Additional showers and thunderstorms and periods of gusty winds Thursday through Sunday.

- Thunderstorms may produce gusty winds 40-60 mph and blowing dust, heavy rain, and hail through the week.

SHORT TERM /Through Friday Night/

Issued 338 AM MDT WED MAY 27 2026 Active weather will continue through the end of the week as a closed upper low over the western Great Basin brings rounds of showers and thunderstorms to our area. Today, strong southeast flow aloft will transport warmer air and additional moisture into our area. This combined with daytime heating will provide ample instability and shear for thunderstorm development, especially in northern areas, this afternoon and evening as an embedded shortwave lifts north. Additionally, dry low levels especially across southeast Oregon will add to wind gust potential. Strong thunderstorms are possible with wind gusts to 60 mph, blowing dust, small hail, and brief heavy rain the primary hazards. The highest chance for thunderstorms (30-50%) will be across southeast Oregon and west-central Idaho north and west of Boise, with a 10-20% chance across the rest of southwest Idaho, lowest in the Magic Valley. High temperatures today will be 10-20 degrees warmer than Tuesday with lower valleys reaching the low to mid 80s. Winds will be gusty late this morning and afternoon, strongest across southeast Oregon and southwest Idaho south of Boise with gusts 30-40 mph.

Conditions Thursday will be similar to today as the low remains nearly stationary. Strong thunderstorms will once again be possible, with the highest potential remaining across southeast Oregon and west-central Idaho. Temperatures will be similar with breezy southerly winds gusting to 20-35 mph. On Friday, the upper low will start to lift north as an upper trough approaches the Pacific Northwest. Showers and thunderstorms will increase across the area as the low approaches with localized heavy rain possible from storms. Temperatures will cool by 5-10 degrees, and winds outside of thunderstorms will not be as breezy as previous days.

LONG TERM /Saturday through Wednesday/

Issued 338 AM MDT WED MAY 27 2026 Showers will continue into Saturday, as the low that has been stagnant over the Great Basin finally lifts over our area. The better forcing associated with this looks to remain east of our area, although higher terrain will likely (60-90% chance) see showers with it. Afternoon destabilization will also allow for a slight chance of mountain thunderstorms come Saturday afternoon. Uncertainty begins to increase come Sunday, mainly owing to the track and strength of a shortwave immediately following the exiting low. For now will maintain a 20-40% chance of showers over the higher terrain in SW Idaho. As has been the common trend this past stretch of weather, afternoon destabilization will support a slight chance of mountain thunderstorms. A drying trend will set in Monday through Wednesday of next week, as ridging builds in behind the shortwave. Temperatures will trend upward throughout the long- term period, reaching near normal come Sunday before increasing to 10-15 degrees above normal come Wednesday.

AVIATION /18Z Wednesday through Thursday/

Issued 1126 AM MDT WED MAY 27 2026 VFR. Isolated showers continuing through the early afternoon, then scattered showers/thunderstorms this afternoon. Thunderstorms capable of small hail, outflows to 40-50 kt, and brief heavy rain. Showers/thunderstorms tapering off after sunset. Surface winds outside of storms: NE-SE 10-25 kt with gusts to 30-40 kt early afternoon through evening. Winds aloft at 10kft MSL: E-SE 20-35 kt.

KBOI...VFR. A 30% chance of thunder over terminal this afternoon 20z-Thu/00z. Storms capable of outflows of 30-45 kt, small hail, and brief heavy rain. Showers and storms tapering off after Thu/00z. Surface winds outside of storms: NW 8-12 kt early this afternoon, then S-SE 10-15 kt with gusts 20-25 kt late afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.