textproduct: Boise

KEY MESSAGES

- Dry with temperatures warming to around 10 degrees above normal by Wednesday.

- Breezy Wednesday and Thursday with shower and thunderstorm potential across the east-central Oregon and west-central Idaho.

- Mostly dry through the weekend with temperatures swinging from around 10 degrees above normal on Friday to around 5 degrees below normal by Sunday.

SHORT TERM /Through Wednesday Night/

The upper level pattern will transition to a shortwave ridge over the area which will bring dry and warmer weather through Wednesday. Flow aloft will shift to the southwest on Wednesday as a shortwave trough approaches the Pac NW coast. Current modeling tracks the trough along WA/OR border Wednesday afternoon, supporting a 20-30% chance of showers and thunderstorms across SE Oregon and the w-central ID mountains. A lower probability (5-10%) exists for the Snake Plain by Wednesday evening. Gusty southwest winds will shift to the NW behind a cold frontal passage Wednesday afternoon/evening. The shower/storm threat tapers off across SE Oregon Wednesday night, while a low chance remains in the w-central Idaho mtns. Temperatures will warm to around 10 degrees above normal by Wednesday.

LONG TERM /Thursday through Monday/

To start Thursday, an upper-level shortwave trough will be moving out of the area to the northeast. Precipitation and cloudy skies may linger through Thursday afternoon in our northern CWA (particularly Valley county), but should move out by evening. Cooler temperatures and breezy daytime winds are expected as the system moves out on Thursday. Temperatures will rebound quickly by 5-10 degrees on Friday as southwesterly flow overspreads the region ahead of a deep upper-level trough moving into the Pacific NW. As the weekend progresses, the upper-level low will gradually move across the Southern Canadian provinces / International border. For our area, winds will remain breezy as an accompanying cold front approaches the area. Latest model runs depict the cold frontal passage on Saturday for E Oregon and SW Idaho, increasing shower/thunderstorm chances (15-30%) across northeast Oregon and the central Idaho mountains over the weekend. Temperatures will cool several degrees for Saturday, but further cooling is anticipated Sunday as the trough moves overhead. Gusty winds will persist Sunday from the traversing trough, but should decrease by Sunday night. Drier and warmer conditions are likely to return Monday as the trough weakens and departs toward the east.

AVIATION /18Z Monday through Tuesday/

Issued 1147 AM MDT MON JUN 1 2026

VFR and high clouds. Cumulus buildups and isolated showers over west-central and southwest Idaho this afternoon. Surface winds: W to NW 5-15 kt this afternoon. Gusts around 20 kt from KBOI to KJER/KTWF. Winds aloft at 10kft MSL: westerly 5-15 kt.

KBOI...VFR and high clouds. Surface winds: NW 6-12 kt with occasional gusts to 15-20 kt this afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.