textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Snow showers continue over the central Idaho mountains through Friday with light accumulations.

- Winds will remain gusty today and Friday.

- Patchy frost tonight, with widespread frost or light freeze possible Saturday morning.

- Remaining unsettled through the weekend and into next week. Temperatures will gradually warm towards normal.

SHORT TERM /Through Saturday Night/

Issued 329 AM MDT THU APR 23 2026 Northwest flow will prevail through the short term as an upper low spins over southern Canada. A couple of shortwave troughs will drop down the backside of the low and clip the northern part of our area today and Friday. This will produce snow showers over the central Idaho mountains with mostly dry conditions elsewhere. Snow levels will be 3500-5000 feet, allowing for light snow accumulations in the mountains. Less than 1 inch of snow is expected in most mountain communities. Weak daytime instability today will also support a 10-20% chance of thunderstorms in the mountains. Winds will remain gusty today, strongest in the Magic Valley and Camas Prairie with gusts 30-45 mph this afternoon, and generally 20-35 mph elsewhere. Winds will start to subside but remain breezy on Friday. Temperatures will be around 5-8 degrees below normal.

Low temperatures tonight will drop into the mid 30s in most agricultural valleys, allowing for patchy frost. However, light to moderate winds and partly cloudy skies should keep temperatures from dropping closer to freezing. However, on Friday night, winds will subside and skies will clear, allowing for a higher potential of a frost or light freeze.

On Saturday, a broad trough will extend into the Pacific Northwest and begin to merge with a trough over California. This will bring a 20-50% chance of showers to areas near the Nevada border. Winds will be much lighter with temperatures a couple degrees warmer than Friday.

LONG TERM /Sunday through Thursday/

Issued 329 AM MDT THU APR 23 2026 A broad trough situated over southern Canada and the northern U.S. will keep temperatures slightly below normal across southeast Oregon and southwest Idaho Sunday into early next week. This pattern will promote afternoon instability and bring a 25-40% chance of daily showers through Tuesday, primarily over higher terrain. As the trough shifts eastward mid-week, the air mass over the forecast area will begin to modify as weak ridging simultaneously builds to the west. Conditions should trend warmer and drier during this transition, with temperatures climbing to around 5 degrees above seasonal normals by Thursday.

AVIATION /18Z Thursday through Friday/

Issued 1139 AM MDT THU APR 23 2026

Areas of low stratus over KMYL-KTWF improving to VFR by early afternoon. Scattered IFR snow/mixed showers and ceilings over northeast OR and w-central ID through tonight. Snow levels: 4.5-5.5 kft MSL. Surface winds: W-NW 5-15 with gusts to 20-30 kt, except 15-25 kt with 30-35 kt gusts near KTWF/KJER. Winds aloft at 10kft MSL: NW 20-40 kt.

KBOI...VFR. Surface winds: NW 8-15 kt with gusts to 20-25 kt, then W-NW 4-8 kt overnight.

Weekend Outlook...Generally VFR. Unstable conditions will support chance of IFR snow/mixed showers over higher terrain Fri-Sun afternoons, along with occasional valley rain showers. Slight chance of thunderstorms near NV border Sat/Sun. Snow levels: lowest Friday at 3-4kft MSL, rising to 4-6kft MSL Sat/Sun. Mtns obscured in showers. Surface winds: NW-N 10-20 kt with 20-30 kt gusts Friday, then W-NW 5-15 kt with 15-25 kt gusts Sat/Sun.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.