textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Showers north and scattered thunderstorms south for the rest of this afternoon, followed by gradual clearing tonight.

- Daytime temperatures remaining near normal through Sunday, then hotter and drier Monday through Wednesday, and remaining hot and dry Thursday.

SHORT TERM /Through Monday Night/

Issued 221 PM MDT SAT JUN 20 2026 Today's rain has greatly moistened the lower atmosphere and showers should keep northern areas cool, moist, and stable the rest of today, with partial clearing tonight. Southern areas, however, have partially cleared and rapid destabilization has led to thunderstorm development that will continue the rest of the afternoon, ending early evening in south- central Idaho. The clearing and cooler overnight and mostly sunny Sunday. Continued mostly clear into Monday and 3 to 5 degrees warmer than Sunday.

LONG TERM /Tuesday through Saturday/

Issued 221 PM MDT SAT JUN 20 2026 A ridge of high pressure will continue to build over the West Coast through Thursday, bringing a gradual warming and drying trend through the middle of the week. Hot daytime temperatures will peak on Wednesday, with valleys seeing highs in the upper 90s and near 100F. Higher elevations will see temperatures in the upper 80s. A weak shortwave trough will help cool temperatures down and bring a low chance of mountain showers on Thursday. Conditions will briefly dry out late Thursday into early Friday. Then, a much more impressive closed low pressure system will move into the Pacific Northwest on Friday, bringing widespread precipitation and cooler temperatures through the weekend. Model agreement in the storm track of this low remains high through Friday-early Saturday, but disagreement remains on how long the low will linger over the region into the weekend.

AVIATION /00Z Sunday through Monday/

Issued 548 PM MDT SAT JUN 20 2026

VFR. Scattered showers and thunderstorms near NV border, and isolated in w-central Idaho. Outflow winds 25-40 kt, brief heavy rain, small hail, and lightning are the main hazards. Mountain obscuration in mountain showers. Clearing skies overnight through Sunday. Surface winds: W-NW 5-15 kt with gusts 20-30 kt. Then, variable up to 12 kt after sunset. Winds aloft at 10kft: westerly 10-20 kt.

KBOI...VFR. Clouds clearing overnight. Surface winds: N-NE 5-10 kt, then variable or light SE overnight.

Sunday Outlook...VFR. Isolated afternoon convection near ID/NV border. Surface winds: W-N 5-15 kt with PM gusts to 15-20 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Red Flag Warning until 9 PM MDT this evening for IDZ423-426. OR...Red Flag Warning until 8 PM PDT this afternoon for ORZ670-672.