textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Scattered thunderstorms south of a line from Burns OR to Jordan Valley OR to Twin Falls ID, this afternoon and evening.

- Thunderstorms capable of producing outflow winds up to 55 mph this afternoon and evening.

- Little chance of thunderstorms the rest of the week, except a slight chance in the central ID mountains Wednesday afternoon, and near the NV/ID border Friday-Sunday afternoons.

- Warming Monday and Tuesday, holding level Wednesday, then gradually cooling the rest of the week.

SHORT TERM /Through Wednesday Night/

Issued 430 AM MDT MON AUG 24 2026 Upper level ridge will rebound over the area and bring warmer temperatures today and monsoonal moisture from the south. Moisture values in the atmosphere increase from the 20th percentile to the 85th percentile by this evening. A shortwave moving in the southwest flow aloft will trigger scattered showers and thunderstorms over far SE Oregon and southern ID south of the Snake Basin, generally from Burns OR, to the Owyhee Mountains to Twin Falls ID and areas south. Storms will generally weaken into showers as they move northeast into the Snake Basin, but outflows up to 55 mph and blowing dust will still be a threat. Showers taper off overnight into Tuesday. Lingering moisture will remain over the area for isolated thunderstorms on Tuesday afternoon over southwest Idaho. A weak wave will move over the region on Wednesday with mostly cloudy skies. Thunderstorm development will be limited on Wednesday due to cloud cover, but isolated thunderstorms over southwest Idaho possible.

LONG TERM /Thursday through Monday/

Issued 430 AM MDT MON AUG 24 2026 An upper level trough off the West Coast will push the monsoon moisture south and east of our area. Height falls throughout the period will allow for a slight cooling trend. Temperatures will be around 5 degrees above normal Thursday, before cooling to near normal Friday and Saturday, and slightly below normal on Sunday. Uncertainty begins to increase late this week, following the lifting of the initial trough and associated frontal passage as tropical activity in the Pacific enhances the jet stream. Models do not handle the energy transfer well in these situations so expect lots of changes in the far extended period.

AVIATION /12Z Monday through Tuesday/

Issued 623 AM MDT MON AUG 24 2026 VFR. Areas of wildfire smoke. Scattered thunderstorms this afternoon south of a line from KBNO-KMAN-KTWF. Surface winds: variable 5-10kt, except gusty erratic outflow winds up to 45kt possible this evening causing BLDU. Winds aloft at 10kft MSL: SW 10-20 kt.

KBOI...VFR. Isolated showers this evening. Surface winds: variable 5-10kt. Gusty outflow winds up to 35kt possible this evening.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Red Flag Warning from noon today to 8 PM MDT this evening for IDZ423-426. OR...Red Flag Warning from 3 PM this afternoon to 8 PM PDT this evening for ORZ670>672.