textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Above normal temperatures through next weekend with Today and Friday being the hottest days. - The hot temperatures Today and Wednesday will be accompanied by gusty winds and very dry conditions.

- A chance of showers and thunderstorms returns to the area Friday and Saturday.

SHORT TERM /Through Thursday Night/

Issued 309 AM MDT TUE JUN 16 2026 An upper level trough passing north of the area will tighten surface pressure gradients across southeast Oregon and southwest Idaho today and Wednesday. This setup will generate gusty westerly winds each afternoon especially along the I-84 corridor through the night.. At the same time, a very dry air mass remains entrenched over the region. Min relative humidity values will drop into the 10 to 15 percent range across most lower elevations, creating elevated to critical fire weather conditions. Wind gusts today will generally reach 25 to 35 mph, with the strongest gusts expected across southeastern Oregon and the western Magic Valley. Despite the weakened upper level ridge, temperatures will reach the mid 90s today which is about 15 degrees above normal for the lower valleys. Slight cooler temperatures on Wednesday behind the dry cold frontal passage, though they will still reach the upper 80s in the lower valley. Dry and stable conditions prevail on Thursday as brief riding builds over the Great Basin.

LONG TERM /Friday through Tuesday/

Issued 309 AM MDT TUE JUN 16 2026 Model guidance remains in excellent agreement regarding a potent, upper level trough diving south from the Gulf of Alaska into the Pacific Northwest by Friday morning. Pre-frontal southerly flow will pull a plume of deep moisture into eastern Oregon and western Idaho starting Friday afternoon. Strong dynamic forcing combined with steep lapse rates will trigger thunderstorm activity primarily along the Idaho/Nevada border Friday afternoon and evening. Given the inverted-v profiles, a few stronger storms could be capable of producing gusty outflow winds.

The upper level trough moves directly over the forecast area on Saturday. This will maintain a threat for showers and thunderstorms, though activity will transition to a wetter storm as the boundary layer moisten. Temperatures on Saturday will drop though remain about 5 to 8 degrees above normal. The trough begins to lift northeast into Montana on Sunday, leaving a cool and unstable northwesterly flow across the region with lingering showers over the higher terrain. Drier and warmer conditions return by next Monday as high pressure tries to rebuild from the southwest.

AVIATION /12Z Tuesday through Wednesday/

Issued 557 AM MDT TUE JUN 16 2026 VFR. Clouds clearing by early afternoon. Hot temperatures will cause high density altitudes across the area this afternoon. Surface winds: light and variable, becoming W-NW 10-20 kt gusting 25-30 kt this afternoon. Winds aloft at 10kft MSL: NW 10-20 kt.

KBOI...VFR. High density altitude this afternoon. Surface winds: light and variable, becoming NW 10-20 kt this afternoon. Gusts NW 25-30 kt after 17/01z.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.