textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Isolated showers and thunderstorms this morning in the central ID mountains.

- A significant pattern change arrives Friday as a cool upper level trough pushes a cold front through, bringing widespread showers and cooler temperatures.

- Temperatures around 15 to 20 degrees below normal Saturday and Sunday.

- Significant precipitation and light snow above 7000 feet possible Saturday through Sunday.

SHORT TERM /Through Saturday Night/

Issued 419 AM MDT THU JUN 25 2026 A weak shortwave is moving over the area this morning with isolated showers extending from the Owyhee Mountains to the Boise Mountains this morning. Showers may produce brief gusty winds this morning. These showers will move east by mid morning with partial clearing and another warm day this afternoon. The upper level trough off the Pacific NW coast will bring increased clouds late this afternoon and evening. Generally cloudy skies with virga and gusty winds this evening as it takes some time to moisten up the lower levels of the atmosphere. Showers become widespread on Friday morning in eastern OR and spread across southwest ID by midday. Then partial clearing expected Friday afternoon as cooler air aloft moves overhead. This will lead to unstable conditions with scattered showers and thunderstorms during the afternoon. Showers continue into Saturday with isolated thunderstorms. Breezy northwest winds continue behind the cold front. Temperatures lower to around 15 to 20 degrees below normal Saturday. Significant precipitation possible with this system, but will be showery in nature, and depending on where the track of the system goes. As it stands right now, precipitation amounts of up to 1 to 1.25 inch possible over the central ID mountains, with lesser amounts in eastern OR, where 0.25-0.5 inch expected. Snake Plain will generally see 0.25 to 0.5 inch.

LONG TERM /Sunday through Thursday/

Issued 419 AM MDT THU JUN 25 2026 Cool and showery conditions continue Sunday with a slight chance of thunderstorms as the trough slowly moves overhead and northeast. Temperatures remain around 15 to 20 degrees below normal Sunday. Light snow possible on the peaks above 7000 feet Sunday morning. Conditions dry out with breezy and continued cool conditions on Monday. Models are now trending toward keeping unsettled conditions through Wednesday, with a weak shortwave moving over northeast OR on Tuesday, and showers favoring the mountains. Below normal temperatures expected through Wednesday but temperatures slowly warm to near normal by Thursday as conditions dry out.

AVIATION /12Z Thursday through Friday/

Issued 615 AM MDT THU JUN 25 2026 VFR. Isolated virga/light rain showers with isolated thunderstorms through midday, mainly east of KBOI and north of KJER. Increasing clouds with virga and showers developing late, with a cold front approaching from the west. Surface winds: variable 10kt this morning becoming SW-NW 10-20 kt during the afternoon, and NW 10-20kt tonight. Gusty winds with virga and onset of showers late. Winds aloft at 10kft MSL: W-SW 10-20kt.

KBOI...VFR. Showers developing Fri morning. Surface winds: W-NW 5-15kt, gusty with virga and showers Fri morning.

Weekend Outlook...Scattered showers and isolated thunderstorms Saturday and Sunday. Mountains obscured. Snow levels lowering to 6500-7500ft Sunday morning. Breezy west-northwest surface winds during the afternoons.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.