textproduct: Boise

KEY MESSAGES

- Isolated afternoon thunderstorms today and Wednesday, mainly forming over the Idaho mountains, and southern Twin Falls County on Thursday afternoon.

- A slight warming trend Tuesday and Wednesday, then gradually cooling the rest of the week with breezy conditions.

- Scattered showers and thunderstorms over southwest Idaho on Friday and Saturday. Some of the storms may be severe.

SHORT TERM /Through Thursday Night/

A seasonably strong anticyclone over Arizona and New Mexico is dominating the synoptic pattern over the western CONUS, leaving the interior Northwest in broad and strengthening southwest flow aloft. This also means warm temperatures will continue with little day-to-day change through Thursday. The primary concerns will revolve around the potential for thunderstorms each afternoon, and then increasing winds with low humidity by Thursday. Thunderstorms are most likely near the Nevada border into the western Magic Valley both this afternoon and Wednesday afternoon, with strong gusty winds the primary threat. Isolated thunderstorms are still possible over the central Idaho mountains as well. Drier air will limit any thunderstorm potential over eastern Oregon, including Malheur/Harney and the Oregon Outback, with only low probabilities existing over Baker County. By Thursday, the increase in southwest flow aloft associated with a strengthening trough ejecting eastward across Oregon will bring gusty winds to southeast Oregon and far southwest Idaho. This will combine with the antecedent low RH/dry conditions and warm temperatures to create an elevated wind-driven fire weather threat across these areas.

AVIATION /18Z Tuesday through Wednesday/

Issued 1153 AM MDT TUE AUG 25 2026

VFR. Isolated showers and thunderstorms this afternoon, mainly east of a KMYL-KBOI line and near KTWF/KJER. Thunderstorms capable of outflows to 35-45 kt. Surface winds: SE-SW 5-15 kt. Winds aloft at 10kft MSL: SW 10-25 kt

KBOI...VFR. A low chance (<10%) of showers and thunderstorms this afternoon after 22z, capable of outflows to 30 kt. Surface winds: Variable, leaning W-NW 5-10 kt this afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Fire Weather Watch from Thursday afternoon through Thursday evening for IDZ423. OR...Fire Weather Watch from Thursday morning through Thursday evening for ORZ670>672. Air Quality Alert until noon PDT Wednesday for ORZ062.