textproduct: Boise

KEY MESSAGES

- Fire weather risk continues due to thunderstorm activity today.

- Thunderstorms with heavy rain may also increase the risk for flash flooding, especially for recent burn scars today and Saturday.

- Temperatures near to slightly below normal through early next week.

SHORT TERM /Through Sunday Night/

The combination of dynamic, southwest flow aloft and presence of monsoon moisture is supporting scattered showers and thunderstorms early this morning. Storm activity is currently favoring far east Oregon and portions of southwest/west-central Idaho, with gusts up to 35 mph possible through morning. A brief lull in activity is expected late morning, before resurgent moisture and troughing allows the re-generation of storms across northeast Oregon and west-central/south-central Idaho late afternoon and evening. Latest guidance indicates localized storm outflow gusts to 40-45 mph are possible with stronger storms. Relatively high precipitable water values will also support heavy rain potential under storm cores. These thunderstorm hazards will create fire weather risks as well as flash flooding concerns across steep terrain and local burn scars.

A brief window of drier, more stable air will help diminish storm activity Friday night, before the next shortwave trough arrives Saturday. Shower and thunderstorm chances will increase once again Saturday afternoon, generally across southwest/central Idaho and northeast Oregon. Gusty outflows and bursts of heavy rainfall will continue to be the main storm threats. Temperatures both Friday and Saturday will remain slightly below normal due to cloud cover, precip, and the PNW trough influence.

Shower activity will decrease Sunday as high pressure builds northwest into the forecast area throughout the day. Residual moisture and daytime instability will be enough to keep a slight chance of showers/thunderstorms over the higher terrain Sunday afternoon. Temperatures will rise a few degrees from Saturday.

LONG TERM /Monday through Friday/

A shortwave trough is expected to arrive from the northwest on Monday, effectively squashing the upper ridge toward the southeast. Enhanced lift with continued moisture will increase shower and thunderstorm chances late Monday through Tuesday across the southwest/central Idaho terrain. Further cooling can be expected Tuesday as the trough makes its way east through the Northern Rockies. The resultant west-northwest flow aloft will then nudge the moisture out of the forecast area while also promoting slightly cooler than normal temperatures late Tuesday through Wednesday. Thereafter, latest model runs are depicting the return of the upper level ridge across the West by late in the week, which would promote warming and potentially re-open the door for the next round of moisture.

AVIATION /06Z Friday through Saturday/

Issued 1204 AM MDT FRI AUG 14 2026

Scattered showers and isolated thunderstorms continue this morning, especially from the Treasure Valley up to KBKE/KMYL. Outflow gusts up to around 30 kt near thunderstorms. Then, thunderstorm coverage will increase in the afternoon with potential outflows to 30-40 kt, mainly around KBKE/KMYL and the KTWF/KJER area. Localized MVFR and mtn obscuration with rain shafts. Surface winds: variable 5-15 kt, with erratic gusts near storms. Winds aloft at 10kft MSL: W-SW 5-15 kt.

KBOI...VFR with reduction in visibility/foothill obscuration due to wildfire smoke. A 20% chance of showers and thunderstorms through mid-morning. Surface winds: SE 8-15 kt with periods of gusts to 20-25 kt. Transitioning to NW in the late afternoon.

Weekend Outlook...Isolated to scattered showers and thunderstorms continuing Saturday. Storms Saturday capable of heavy rain, strong gusty outflows, and MVFR conditions. Showers taper off come Sunday. Surface winds: SW-SE 5-15 kt Saturday, then SW-NW 5-10 kt Sunday. Light and variable during overnights.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Red Flag Warning until 6 AM MDT early this morning for IDZ400>403-420-421. Red Flag Warning until 8 PM MDT this evening for IDZ423-424- 426. Flash Flood Watch from noon MDT today through Saturday evening for IDZ013. OR...Red Flag Warning until 5 AM PDT Friday for ORZ670>672. Red Flag Warning until 8 PM MDT /7 PM PDT/ this evening for ORZ673>675. Air Quality Alert until 1 PM MDT /noon PDT/ this afternoon for ORZ061-063-064.