textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Breezy and cooler Monday, with showers continuing in the north, but becoming sunny in the south.

- Warmer and drier Tuesday through Thursday.

- Cooler and unsettled conditions possible on Saturday and Sunday.

SHORT TERM /Through Wednesday Night/

Issued 236 PM MDT SUN SEP 6 2026 An upper level trough continues to track across southern OR this afternoon. Showers and thunderstorms increase late this afternoon across eastern OR, with isolated showers and thunderstorms over the west central ID and Owyhee mountains. Showers will increase in coverage this evening as the upper level low tracks across southern ID early Monday morning. The precipitation will quickly taper off across eastern OR and the Snake Basin in southwest ID early Monday morning, with lingering showers over the central ID mountains through Monday afternoon. A convergence zone will set up in wake of the Wallowas late Monday afternoon keeping showers and thunderstorms north of McCall late into the evening. Drier and warmer conditions expected on Tuesday.

LONG TERM /Thursday through Monday/

Issued 236 PM MDT SUN SEP 6 2026 A warming trend will continue Wednesday through Thursday as the cool core upper level trough moves east with weak ridging. A trough from the Gulf of Alaska will move south along the BC coast into the Pacific NW by Saturday with cooler and windy conditions possible next weekend. Uncertainty remains elevated in the extended period, as tropical activity in the Pacific enhances the jet stream. Models do not handle the energy transfer well in these situations so expect lots of changes in the far extended period over the next week with all these tropical systems across the Pacific.

AVIATION /06Z Monday through Tuesday/

Issued 1227 AM MDT MON SEP 7 2026 Cold front moving W to E, bringing scattered showers and isolated lightning in NE Oregon and central Idaho through Monday morning. Then, isolated showers in w-central Idaho Monday afternoon. MVFR in heavier showers. Snow levels 8kft MSL. Patchy fog/low stratus in mountain valleys and near KJER through morning. Mountains obscured, improving Monday afternoon. Surface winds: decreasing to SW-NW 5-15 kt overnight. Winds aloft at 10kft MSL: W 15-25 kt.

KBOI...Generally VFR. A 10% chance of rain showers before Mon/09Z. Surface winds: NW or variable around 5 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.