textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Strong cold front moving eastward across Idaho zones this afternoon bringing gusty northwest winds, areas of blowing dust, and falling temperatures.

- Saturday will be 10 to 20 degrees cooler than today, but less windy.

- Weak upper level low pressure supports a slight chance of showers and afternoon thunderstorms near the Nevada border and in central Idaho on Sunday.

- Seasonable temperatures and dry Monday through Thursday. Slight chance of rain and snow showers in the central Idaho mountains on Friday, but continued dry elsewhere.

SHORT TERM /Through Sunday Night/

Issued 200 PM MDT FRI SEP 25 2026 A strong cold front was moving eastward across western Idaho this afternoon marked by a wind shift from southeast to gusty northwest and rapidly falling temperatures. Strongest gusts, up to 45 mph, with areas of blowing dust, will occur in the Snake Basin between Boise and Twin Falls until around 6 PM MDT. Showers behind the front will be limited to northernmost mountain areas with only minimal rainfall expected. The rest of our CWA will be mostly cloudy but dry as the frontal zone passes. Skies will clear from west to east tonight and winds will die down leading to significantly cooler temps overnight. Clouds will increase again toward morning in eastern Oregon as the next upper trough comes in from the Pacific. Clouds will spread across our Idaho zones Saturday and continue or increase further in all areas Saturday afternoon and Saturday night, and continue through Sunday, finally clearing in eastern Oregon Sunday night and western Idaho Monday. Models have a 15-30 percent chance of showers and thunderstorms Sunday afternoon in the central Idaho mountains and near the ID/NV border. Saturday will be about ten degrees cooler than normal, then 2-4 degrees warmer Sunday, and another 2-4 degrees warmer Monday.

LONG TERM /Monday through Friday/

Issued 200 PM MDT FRI SEP 25 2026 Tuesday looks breezy, dry, and slightly cooler as the next broad upper trough from the north Pacific comes inland and puts our area under strong zonal flow. Models continue in wide disagreement after that with GFS steadily deepening the trough for continued cooling while ECM weakens the trough for gradual warming. Our forecast, based on NBM, favors the warmer ECM through Thursday, then the cooler GFS Friday. The deeper and colder GFS will allow a slight chance of rain showers and even snow showers in the central Idaho mountains on Friday.

AVIATION /00Z Saturday through Sunday/

Issued 609PM MDT FRI SEP 25 2026

Generally VFR. Gusty west to northwest winds this evening behind a cold front. Periods of MVFR/IFR in blowing dust along and right behind the front, although threat should end by Sat/01z. Isolated to scattered showers this evening, primarily near KMYL and in the central-ID mountains. Surface winds: W-NW 10-15 kt with gusts to 25 kt this evening. Decreasing to W-NW 5-10 kt Sat/AM. Winds aloft at 10kft MSL: W 15-30 kt.

KBOI...VFR. NW winds with periodic gusts to around 20 kt lingering this afternoon. Winds decreasing to W-NW 6-12 kt after sunset.

Weekend Outlook...VFR with high/mid level ceilings Saturday and Sunday. Isolated showers near NV border and over central ID mtns Sunday. Light NW surface winds.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.