textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Above normal temperatures through next week. Slight cooling Tuesday and Wednesday then warming again Thursday through Saturday.

- Slight chance of afternoon/evening showers and thunderstorms Sunday. Better chance Monday afternoon/evening. Drying from the west Tuesday except in south-central Idaho where a chance of showers/storms will continue.

- Windy Monday afternoon in southeast Oregon and the Snake Basin in Idaho,

SHORT TERM /Through Monday Night/

Issued 213 PM MDT SAT MAY 2 2026 Continued warming through Sunday between an upper ridge over the Great Basin and an upper low off the OR coast. Monday looks slightly cooler as the upper low turns inland over CA and elongates toward northern NV. We have a 10-20 percent chance of showers and thunderstorms late today in southwestern Harney County, expanding Sunday afternoon to include southern Malheur County and the Blue Mountains in Baker County. Monday afternoon and evening look wetter as the upper low comes inland leading to a 20-40 percent chance of showers and thunderstorms all across our southern CWA and the Camas Prairie, but leaving other areas dry. Northwest winds will increase to 15 to 25 mph Monday afternoon in southeast Oregon and the Snake Basin in Idaho southward to the Nevada border, with gusts to 35 mph between Boise and Twin Falls.

LONG TERM /Tuesday through Saturday/

Issued 213 PM MDT SAT MAY 2 2026 A low pressure system off the coast of California will progress across the Desert Southwest on Tuesday, bringing moisture into our region. This will bring increased chances of showers and thunderstorms over southwest Idaho (20-40% chance), with the best chance of precipitation over the Nevada border. The ridge of high pressure situated off the West Coast will keep temperatures warm and allow for northerly flow with gusty winds on Tuesday afternoon. This high will then steadily build over the Western United States through Friday, bringing temperatures 5-10 degrees above normal through the end of the week. A couple of weak shortwave trough passages over Montana will bring elevated afternoon precipitation chances (10-30% chance) over the West Central and Boise Mountains on Wednesday and Thursday.

AVIATION /06Z Sunday through Monday/

Issued 1125 PM MDT SAT MAY 2 2026

VFR with SCT-BKN high clouds overnight through morning. Patchy valley smoke in the West Central and Boise Mountains overnight. Isolated showers and thunderstorms tomorrow afternoon over SE OR and high terrain in SW ID. Gusty and erratic outflow winds with blowing dust are likely near showers and thunderstorms. Surface winds: variable under 10 kt overnight through morning, then NW-NE 7-15 kt in the afternoon/evening. Winds aloft at 10k ft MSL: variable 5-10 kt.

KBOI...VFR with SCT high clouds overnight through morning. Surface winds: SE 5-10 kt overnight through early morning, then NW 5-10 kt in the afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.