textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Clear, warmer, and drier conditions persist through Sunday before rapid warming begins Monday.

- Breezy afternoon winds will impact Baker County and the Lower Treasure Valley today.

- Significant heat arrives Tuesday with temperatures peaking near 15 degrees above normal, followed by a slight cooling trend and a chance of thunderstorms near the Nevada border late in the week.

SHORT TERM /Through Monday Night/

Issued 307 AM MDT SAT JUN 13 2026 An amplified upper level ridge positioned off the Pacific Coast will remain the dominant weather driver for southeast Oregon and southwest Idaho through the weekend. This pattern will support clear skies, dry air, and a steady warming trend across the region. Afternoon high temperatures will push into the mid 80s today and Sunday within the lower valleys. The primary short term concern centers around breezy northwest to north winds developing each afternoon. The strongest winds will be across Baker County into the Lower Treasure Valley where gusts between 20 to 30 mph are likely before winds taper off after sunset. Excellent radiational cooling conditions will remain intact overnight under clear skies, keeping nighttime minimums comfortably cool. High pressure shifts eastward directly over the Intermountain West on Monday, kicking off a period of significant warming with temperatures climbing into the low 90s in the valley.

LONG TERM /Tuesday through Saturday/

Issued 307 AM MDT SAT JUN 13 2026 Model guidance is in strong agreement that Tuesday will be the warmest day of the week, with valley locations likely seeing afternoon highs reaching the mid to upper 90s. This is about 15 degrees above seasonal normals. The ridge will begin to flatten by mid-week as an upper level trough tracks well to our north across western Canada. This evolution will introduce a slight cooling trend by Wednesday and Thursday, though temperatures will remain around 10 degrees above normal. Later in the week, a closed low amplifies and weakens the ridge, dropping temperatures slightly to 5 to 10 degrees above normal by Saturday. Winds continue to gust 20 to 30 mph in the lower Snake Plain through this period, and as the low approaches, the chance for thunderstorms along the Nevada border increases Thursday and Friday.

AVIATION /12Z Saturday through Sunday/

Issued 544 AM MDT SAT JUN 13 2026 VFR, few high clouds. Surface winds: Variable 5-15 kt becoming NW-NE 10-20 kt with gusts to 20-30 kt this afternoon. Winds aloft at 10kft MSL: NW-N 15-25 kt.

KBOI...VFR, few high clouds. Surface winds: W-N 5-15 kt. Gusts to 20- 25 kt will return this afternoon.

Sunday Outlook...VFR and passing high clouds. A few afternoon mountain cumulus. Surface winds: variable 5-15 kt Sunday AM, then NW- NE 5-15 kt with gusts around 20 kt in the afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.