textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Very hot temperatures today through Saturday.

- Smoky conditions continue through the weekend.

- Breezy winds Friday through the weekend with very low thunderstorm chances returning along the ID/NV border.

SHORT TERM /Through Saturday Night/

Issued 348 AM MDT THU AUG 6 2026 Temperatures will stay hot as the upper-level ridge remains over the Great Basin / Four Corners region. The peak intensity of the ridge over the region will be Friday, with maximum temperatures in lower elevations above 100 degrees. Accordingly, a Heat Advisory is in effect starting this afternoon through Saturday evening. Some local areas with morning lows around 70 degrees will be under Major Heat Risk Friday and Saturday, while the rest of the area with morning lows in the 60s and 50s see Moderate to Minor Heat Risk. The ridge will begin to flatten Friday night, with stronger westerly flow aloft moving overhead. This will moderate the temperatures Saturday compared to Friday alongside increasing afternoon wind gusts, especially in southwest Idaho. Beginning Friday through the weekend, wind gusts 20 to 30 mph are possible in open areas and ridges. Elsewhere, gusts up to 20 mph are possible. Additionally, while a very low (<5%) chance, isolated thunderstorms are possible along the ID/NV border Friday and Saturday afternoons. This is a result of some monsoonal moisture reaching the northern Rockies as the Four Corners ridge very slightly weakens and moves a bit east. Smoke impacts are expected to continue.

LONG TERM /Sunday through Thursday/

Issued 348 AM MDT THU AUG 6 2026 The Four Corners ridge will remain with continued flattening over the region from upper-level troughing remaining offshore. Temperatures will be near normal to 5 degrees above normal through the period. Monsoon moisture will continue to reach far SE Oregon and southwest ID south of the Snake Basin through early next week. There is increasing confidence in a slight chance of thunderstorms along the NV border each afternoon. Westerly flow aloft will continue breezy conditions, especially during the afternoons and early evenings. Smoky conditions will continue from area wildfires which may keep temperatures slightly cooler than forecast. By Thursday, a significant pattern change is being converged upon by long range models. The upper-level troughing that has been sitting offshore until now moves inland, bringing cooler temperatures and better chances of precipitation than the area has seen in some time. As with most things this far in the long term, these details are fickle and subject to quick changes forecast to forecast.

AVIATION /12Z Thursday through Friday/

Issued 608 AM MDT THU AUG 6 2026

Reduced visibility due to wildfire smoke, with areas of MVFR-IFR and mountain obscuration, otherwise VFR. High density altitude each afternoon due to hot temperatures. Surface winds: variable less than 10 kt, becoming W-NW 5-12 kt after 18Z/Thursday. Winds aloft at 10kft MSL: W-SW 5-20kt.

KBOI...Wildfire smoke, generally remaining VFR. Mountains obscured at times. High density altitude each afternoon due to hot temperatures. Surface winds: SE 5-9 kt, becoming WNW around 10 kt after 18Z/Thursday.

Weekend Outlook...Wildfire smoke continuing reduced visibilities, with areas of MVFR-IFR and mountain obscuration, otherwise VFR. High density altitude each afternoon due to hot temperatures. Very low (<5%) chance of afternoon thunderstorms along ID/NV border Friday, Saturday, and Sunday. Surface winds: W-NW 7-12 kt with gusts near 20 kt during the afternoon into early evening, variable under 10 kt overnight.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Air Quality Alert until 2 PM MDT Friday for IDZ011>015-028-029- 033. Heat Advisory from 2 PM this afternoon to 9 PM MDT Saturday for IDZ012-014>016-029-030-033. Air Quality Alert until 1 PM MDT this afternoon for IDZ016-030. OR...Heat Advisory from 2 PM MDT /1 PM PDT/ this afternoon to 9 PM MDT /8 PM PDT/ Saturday for ORZ061>064. Air Quality Alert until 1 PM MDT /noon PDT/ this afternoon for ORZ061>064.