textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Breezy conditions overnight, with frost and freeze possible in the Snake Plain, mostly east of Mountain Home.

- Mountain showers on Monday, otherwise dry, breezy and slightly warmer.

- Dry with temperatures warming back above normal starting on Wednesday.

SHORT TERM /Through Tuesday Night/

Issued 237 PM MDT SUN MAY 17 2026 Widely scattered showers this evening will dissipate with sunset, leaving dry conditions and clear skies overnight. The surface pressure gradient behind an eastward exiting low will keep breezy conditions across portions of SE Oregon and through much of the Snake Plain tonight. Low temperatures briefly drop to around freezing Monday morning in portions of the Snake Plain, reaching 31 to 35 degrees east of Mountain Home, while the lower Snake will fall to between 36 and 40 degrees. Have stayed with a Freeze Warning for the western Magic Valley. Monday will be dry and breezy across much of the area, though not as windy as today with gusts of 25-35 mph expected. Afternoon instability will support a slight chance of showers over the mtns but amounts will be light. Northwest flow aloft carries into Tuesday, but a more stable air mass will keep conditions dry across the region as temperatures warm back to near normal.

LONG TERM /Wednesday through Sunday/

Issued 237 PM MDT SUN MAY 17 2026 High pressure building in aloft over the Pacific will keep our area under northwest flow to start the period. Wednesday into Thursday will feature increased cloud cover and light, isolated showers across the West Central Mountains, as an embedded shortwave moves through the intermountain west. This shortwave will also work to slow the warming trend in the long-term period. Come Saturday, a deepening Alaska low will give way to zonal flow aloft. Daytime highs of 5-10 degrees above normal and generally dry conditions are expected through the weekend.

AVIATION /00Z Monday through Tuesday/

Issued 543 PM MDT SUN MAY 17 2026

Generally VFR. Scattered showers and isolated thunderstorms before sunset, mainly SW Idaho. Patchy blowing dust in the Snake Plain and E-Oregon. Localized MVFR/IFR conditions in blowing dust and precip. Snow levels: 4.5-5.5 kft MSL. Surface winds: NW-N 15-25 kt with gusts to 25-35 kt. Overnight, W-N 10-20 kt with gusts to 20-25 kt. Winds aloft at 10kft MSL: N-NE 20-40 kt.

KBOI...VFR. Showers and isolated thunderstorms in the area. A 20% chance of rain/graupel showers hitting terminal before 18/03Z, then clearing. Foothill showers return Monday PM. Surface winds: NW 15-25 kt with gusts to 30-35 kt before sunset. Becoming NW 7-17 kt after sunset, with occasional gusts around 20-25 kt before 18/07Z.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Wind Advisory until midnight MDT tonight for IDZ012-014-015- 029. Freeze Warning from midnight tonight to 8 AM MDT Monday for IDZ016. OR...Wind Advisory until midnight MDT /11 PM PDT/ tonight for ORZ061>064.