textproduct: Boise

KEY MESSAGES

- Breezy winds through the end of the week into the weekend, with the strongest winds on Saturday. - Near to below normal temperatures through the middle of next week, except Friday with highs around 10 degrees above normal.

- A cooler and wetter pattern is likely next week with significant precipitation totals possible.

SHORT TERM /Through Saturday Night/

Zonal flow continues today as a trough off Haida Gwaii moves south along the BC coast today. As the trough moves south, the flow aloft shifts to the southwest, allowing for around 10 degrees of warming on Friday afternoon. This trough will move into WA on Friday afternoon, bringing a dry cold front through eastern OR on Friday evening. Gusty winds up to 35-45 mph possible Friday evening along the I-84 corridor from Baker City to Ontario OR as the cold front moves through. Winds elsewhere will not be fully realized as the cold front passes through during the overnight hours. The trough continues to move across WA on Saturday, with mostly cloudy skies. Showers and thunderstorms will generally be confined to areas north and east of our region, across eastern Idaho and the central ID panhandle. Dry and breezy conditions expected Saturday afternoon, with temperatures near normal or around 10-15 degrees cooler than Friday.

LONG TERM /Sunday through Thursday/

Showers in central Idaho move east Sunday as an upper level trough moves into western Montana. The showers bring a 10-20% chance of precipitation to the northeastern corner of Valley County, with a similar chance of thunder in the afternoon. As the trough moves out, much of Idaho sees gusty winds. Winds will be especially strong in south-central Idaho and parts of the Snake Plain between Boise and Twin falls. Gusts in these areas are forecast to be 25-35 mph. Afternoon maximum temperatures behind the trough will be about 5 degrees below normal.

Temperatures won't have much time to rise following the cool and breezy weekend, as models are in broad consensus bringing a strong trough through Idaho early next week. Models vary the most in the trough's amplitude, whether it closes and vorticity strengthens or remains a wave in the broader flow. This impacts forecasted precipitation coverage the most, but timing and placement is mostly consistent. Precipitation begins to move into southeast Oregon Monday evening, moves over all of southeast Oregon and southwest Idaho on Tuesday, and then southwest/central Idaho as it exits eastward Wednesday and Thursday. These areas see a 20-40% chance of precipitation, except on Tuesday where the core of the low bring a 50-70% chance of precipitation over mountains. Rainfall through the entire event is forecast to total up to 0.1 inches in lower elevations and up to 0.75 inches in mountains. Thunder is possible each day, especially Tuesday. A limiting factor of thunderstorms will be cooler surface temperatures with the low and cloud cover inhibiting instability. Thunderstorms could bring much higher local rainfall amounts to all elevations. The lower surface temps bring some snow to summits and ridgelines. Additionally, wind gusts increase in ridgelines and open areas during the low's passage. Each afternoon sees gusts 15 to 30 mph until Thursday where gusts in southeast Oregon weaken.

AVIATION /18Z Thursday through Friday/

Issued 1100 AM MDT THU JUN 4 2026 VFR, a few high clouds this evening. Surface winds: W-NW 5-15 kt, with gusts 15-30 kt, increasing east of KBOI. Winds light and variable this evening. Winds aloft at 10kft: W 10-20 kt.

KBOI...VFR. Surface winds: NW 8-13 kt, gusts 20 kt in the afternoon. Light SE winds tonight.

Weekend Outlook...Mainly VFR. Mostly clear on Friday with increasing high clouds on Saturday. A 10-20% chance of showers and thunderstorms across the northern mountains Sunday. Surface winds: SW-NW 5-15 kt with gusts 15-30 kt Friday, becoming W-NW 10-20 kt with gusts 20-35 kt Saturday and Sunday.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.