textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Afternoon showers and isolated thunderstorms Wednesday and Thursday, primarily over the higher terrain and near the Nevada border.

- Gradual warming through the week.

- Thunderstorms possible this weekend.

SHORT TERM /Through Thursday Night/

Issued 213 PM MDT TUE APR 28 2026 A cool upper level trough remains the dominant feature across the Pacific Northwest this evening, keeping conditions somewhat unsettled. Patchy frost possible from Mountain Home through the Western Magic Valley Wednesday morning with low temperatures between 36 and 38 degrees. While much of the region will remain dry tonight under clearing skies, the combination of residual moisture and daytime heating will trigger another round of isolated showers Wednesday afternoon. There looks to be enough instability for a slight chance of thunderstorms, particularly across southeast Oregon and along the Idaho/Nevada border. A similar pattern holds for Thursday as the trough begins to shift eastward. Temperatures will continue their steady climb, reaching the low 70s in the lower valleys by Thursday afternoon. This warming, combined with the cold air aloft, will again support a slight chance of afternoon thunderstorms and mountain showers.

LONG TERM /Friday through Tuesday/

Issued 213 PM MDT TUE APR 28 2026 A trend towards warmer conditions will continue into this weekend, with highs expected to range between 8 to 12 degrees above normal. This translates to high temperatures in the upper 70s to near 80 degrees for many lower elevation locations, including the Treasure Valley and western Magic Valley. While this occurs, an offshore low off the California coast will strengthen, and import modest amounts of moisture northward into the region, bringing precipitation chances to southeastern Oregon beginning Sunday, and spreading eastward into southwest Idaho on Monday and Tuesday. Depending on the evolution of the aforementioned closed upper low, isolated thunderstorms will be more likely on Monday and/or Tuesday across southwest Idaho, with locally strong wind gusts likely the biggest threat.

AVIATION /00Z Wednesday through Thursday/

Issued 547 PM MDT TUE APR 28 2026

VFR with mid-high clouds. Scattered mountain showers continue until mid evening in Central Idaho. Snow levels 6000-7000 ft MSL. Surface winds: W-NW 5-15 kt, decreasing to light and variable by sunset. Winds aloft at 10kft MSL: W-NW 5-15 kt.

KBOI...VFR. Surface winds: NW 5-10 kt, becoming southeast around 5 kt late this evening into early Wed morning.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.