textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Hot weather will continue through Monday followed by slight cooling midweek, then trending hotter again beginning Friday, becoming extremely hot next weekend.

- Isolated thunderstorms over higher terrain in eastern Oregon Sunday afternoon and night, spreading into western Idaho Monday, then ending west to east Tuesday. - Breezy winds each afternoon.

SHORT TERM /Through Monday Night/

Issued 217 PM MDT SAT JUL 4 2026 Hot weather will peak Sunday and Monday as westerly flow aloft backs to southwesterly. The increasing southerly component will gradually draw mid-level moisture northward into our CWA, resulting in isolated thunderstorms Sunday afternoon in Harney County, then over the rest of eastern Oregon Sunday night through Monday night. A slight chance of thunderstorms will develop in western Idaho Monday afternoon and Monday night. Due to low-level dryness, lightning and gusty outflow winds to 50 mph will be the primary thunderstorm threats. Outside of thunderstorms, expect breezy conditions in eastern Oregon this evening with gusts 20-35 mph, with similar gusts Sunday afternoon but in Idaho as well.

LONG TERM /Tuesday through Saturday/

Issued 217 PM MDT SAT JUL 4 2026 over the Four Corners region with continued hot temperatures and southwest flow over the area. Residual monsoon moisture continues into Tuesday with a chance of thunderstorms as a shortwave moves across the Pacific NW. Westerly flow shunts the moisture to the east on Wednesday and Thursday with dry and breezy conditions and slightly cooler temperatures. Temperatures Tuesday and Wednesday around 5-10 degrees above normal cooling to near normal on Thursday. The ridge expands over the area on Friday bringing hotter temperatures for next weekend.

AVIATION /00Z Sunday through Monday/

Issued 449 PM MDT SAT JUL 4 2026 VFR. High density altitude this evening due to heat. Isolated thunderstorms over SE Oregon, far SW Idaho, and the central Idaho mountains Sunday late afternoon and evening. Thunderstorms capable of producing gusty outflows up to 50 kt. High density altitude Sunday afternoon/evening due to heat. Surface winds: SW-NW 5-15 kt this evening. NW valley gusts 15-25 kt KBKE to KONO this evening. Otherwise, mostly variable under 12 kt tonight through Sunday morning. Winds aloft at 10kft MSL: SW 10-20 kt.

KBOI...VFR under clear skies. High density altitude this evening and Sunday afternoon/evening due to heat. Surface winds: NW 7-12 kt, becoming SE or variable less than 10 kt overnight through Sunday morning.