textproduct: Boise

KEY MESSAGES

- Dry and warmer through Thursday.

- Cold front and gusty winds Thursday evening, followed by breezy and cooler weather Friday.

- Much stronger cold front late Saturday bring stronger winds (up to 50 mph across the Snake Plain to the Nevada border, showers, and thunderstorms across central Idaho Mountains, then windy and much cooler Sunday.

- Warming and drying early next week.

SHORT TERM /Through Friday Night/

High pressure building over our area will sustain warm, dry, and clear conditions through Thursday. Thursday's highs will be in the upper 70s through 80s, with a couple of spots (e.g., Grand View/ID and Rome/OR) near 90. Meanwhile, an upper shortwave trough will dig southward through the northwest region on Thursday. This system will push a dry surface cold front through our CWA late Thursday, bringing gusty west winds and some high clouds. Following this dry frontal passage, Friday will be cooler, but still holding warmer than normal temperatures. Breezy post-frontal winds from the west will linger over high terrain areas Friday afternoon through sunset.

LONG TERM /Saturday through Wednesday/

Southwest flow ahead of an incoming upper low will keep Saturday on the warmer than normal side. Come late Saturday, the aforementioned upper low will quickly move into our area from off the OR coast. This significant pattern shift will bring a rapid temperature cooldown, strong westerly winds, and widespread precipitation Saturday afternoon/evening. The forecasted winds for late Saturday through early Sunday will be particularly strong, with gusts up to 40 to 50 mph spanning the entire southern half of our CWA from southeast OR near the NV border to the lower Snake River Plain. The northern half of the CWA will see the bulk of showers/thunderstorms, especially the central mountains of western ID and eastern OR, while the Magic Valley stays dry. Showers will continue Sunday morning as moisture wraps around the northern and western flanks of the eastward-moving upper low. The cooling pattern will drop snow levels down to the 7000-8000 ft range, favoring some light snow showers over high mountain peaks. By late Sunday, our western zones should clear, and Sunday night looks clear and cold area- wide, except for valley fog early Monday morning. Then sunny and warmer for the rest of Monday before another upper trough digs SSW-ward from British Columbia and hangs over the northwest coast. Long-term guidance has the low staying off the coast, keeping our area under a warm southwest flow. As such, Tuesday through Wednesday will be dry and warm.

AVIATION /18Z Wednesday through Thursday/

Issued 1146 AM MDT WED SEP 9 2026 VFR with generally clear skies. Surface winds: Variable less than 10 kt, becoming SW-NW 5-10 kt this afternoon after 20Z. Winds aloft at 10kft MSL: W-NW 10-20 kt.

KBOI...VFR with clear skies. Surface winds: Light NW under 10 kt this afternoon through early evening, then returning SE 5-10 kt after Thu/02Z.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.