textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Continued hot through Sunday then gradual cooling through next week.

- Smoke persisting through at least Monday.

- Breezy afternoon winds through Sunday.

- Isolated late-day thunderstorms near the ID/NV border Saturday and Sunday as high-level monsoon moisture advances northward.

SHORT TERM /Through Sunday Night/

Issued 225 PM MDT FRI AUG 7 2026 Hot, smoky weather will persist through the weekend with an upper level high over the Great Basin but gradually weakening. Saturday looks 1-3 degrees cooler than today, and another 2-4 degrees cooler Sunday as a weak Pacific cold front moves through. Low temps will change little, though. Monsoon moisture near the southern ID border will bring a slight chance of late- day thunderstorms Saturday, and again late Sunday but mainly in eastern Owyhee and southern Twin Falls Counties. Thunderstorms will be high-based with strong downdrafts and gusty outflow winds but little rain. Latest smoke models show little if any improvement through the weekend, with worst conditions continuing in eastern Oregon.

LONG TERM /Monday through Friday/

Issued 225 PM MDT FRI AUG 7 2026 Gradual cooling now expected to continue through the coming week whereas yesterday's forecast held temperatures level after Monday. The persistent upper ridge over the Great Basin is forecast to slowly weaken and retreat southward as cooler westerly flow comes in across the northern intermountain region. A low-amplitude trough will develop Wednesday, with the westerly flow changing to southwesterly and again bringing monsoon moisture northward, leading to a slight chance of afternoon thunderstorms near the NV/ID border Wednesday and Thursday.

AVIATION /00Z Saturday through Sunday/

Issued 531 PM MDT FRI AUG 7 2026 MVFR-IFR visibility and mountain obscuration due to wildfire smoke. High density altitude due to hot afternoon temperatures. Surface winds: W-NW 5-15 kt, becoming variable 5-10 kt tonight. Winds aloft at 10kft MSL: W-SW 10-20 kt.

KBOI...Smoke from nearby wildfires impacting visibility with brief MVFR conditions. Foothills briefly obscured in smoke. Surface winds: NW 8 to 14 kt until sunset, then light SE.

Weekend Outlook...Areas of MVFR visibility and local mountain obscuration due to wildfire smoke. High density altitude each afternoon due to hot temperatures. A 15% chance of afternoon thunderstorms along ID/NV border each day. Surface winds: W-NW 5-15 kt with gusts 15 to 25 kt during the afternoons/early evenings, otherwise variable less than 10 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Air Quality Alert until 1 PM MDT Monday for IDZ011>015-028-029- 033. Heat Advisory until 9 PM MDT Saturday for IDZ012-014>016-029- 030-033. OR...Air Quality Alert until 1 PM MDT /noon PDT/ Monday for ORZ061>064. Heat Advisory until 9 PM MDT /8 PM PDT/ Saturday for ORZ061>064.