textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Dry with temperatures 10 to 20 degrees above normal through next week.

- Sunday is the warmest day, when highs will approach or exceed daily records.

- A minor disturbance on Monday will bring a low chance of showers and thunderstorms to higher terrain along the Nevada border and across central Idaho.

SHORT TERM /Through Sunday Night/

Issued 238 PM MDT FRI OCT 2 2026 The forecast remains consistent in showing amplification of the Desert SW ridge over the weekend. This will push temperatures into record territory by Sunday as lower elevations reach the upper 80s to low 90s. The probability of reaching 90 has bumped up slightly across portions of SE Oregon and upper Treasure Valley in Idaho, reaching 50-70% between Boise and Hagerman. The dry air mass and longer nights will allow for temperatures to cool off closer to normal overnight while afternoon highs reach 10-20 degrees above normal. Winds will remain light with local haze/smoke from prescribed fires. Clouds will increase late Sunday ahead of a shortwave trough moving onto the West Coast. Given the warm temperatures on Sunday, the cloud cover could play a role in setting record warm overnight lows Sunday night.

LONG TERM /Monday through Friday/

Issued 238 PM MDT FRI OCT 2 2026 A passing shortwave disturbance will move through the area on Monday, flattening the ridge. This weak system will provide cloud cover, low precipitation chances (5-10%, primarily over the higher terrain along the Nevada border and central Idaho), and cooling temperatures by a few degrees (but overall remaining well above normal). As the trough moves out, the upper-level ridging will build right back in, keeping our temperatures warm for this time of year. Clear skies, dry conditions, and warm temperatures are forecast Tuesday through Thursday.

Early Friday morning, an upper-level trough will approach the Pacific Northwest. Temperatures are expected to remain warm through Friday with cooler temperatures and higher precipitation chances not arriving until the weekend, but confidence on the timing and intensity of this system is low. Depending on the intensity and timing, the range of possibilities is vast; ranging from some tropical moisture moving into the area to an intense mid-latitude cyclone bringing much cooler air. For now, uncertainty remains too high to message anything strongly.

AVIATION /00Z Saturday through Sunday/

Issued 452 PM MDT FRI OCT 2 2026

VFR. Areas of smoke may reduce visibility near prescribed burns. Surface winds: 10 kt or less through tonight. Winds aloft at 10kft MSL: W 10-20 kt.

KBOI...VFR through Sunday with periods of high cloud cover. Surface winds less than 10 kt through the weekend.

Weekend Outlook...VFR with mostly clear skies. Areas of smoke may reduce visibility near prescribed burns. Surface winds: variable less than 10 kt on Saturday, E-S 5-10 kt on Sunday.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.