textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Light mountain snow showers and breezy winds today.

- Widespread frost and areas of freezing temperatures late tonight into Saturday morning.

- Remaining unsettled through the weekend and into early next week. Temperatures will gradually warm toward normal by mid week.

SHORT TERM /Through Sunday Night/

Issued 238 AM MDT FRI APR 24 2026 An upper low will remain over the Northern Plains / Southern Canada through the short term. A weak shortwave trough will dive down the backside of the low today and clip the northern part of our area. This will produce scattered snow showers across the west-central Idaho mountains with dry conditions elsewhere. Despite snow levels on mountain valley floors, any accumulations will be minimal. Highs today will be 5-10 degrees below normal. Winds will be breezy this afternoon across southern Idaho with gusts 20-35 mph. With a cool airmass in place, light winds, and mostly clear skies, temperatures will dip to near or below freezing tonight in agricultural valleys. A Freeze Watch remains in effect for these areas.

Additional shortwave energy dropping down the backside of the low will merge with a broad upper level trough over California over the weekend. The resultant broad trough over the Pacific Northwest will keep temperatures cool with a 20-50% chance of showers over the higher terrain along with a 10% chance of thunderstorms each afternoon. Snow levels will be 4000-5500 feet, with minor accumulations possible on higher peaks. Winds will be lighter on Saturday, then breezy again Sunday as surface low pressure moves over eastern Idaho. Areas of frost will develop Saturday and Sunday nights, but lows should not be as cold as tonight.

LONG TERM /Monday through Friday/

Issued 238 AM MDT FRI APR 24 2026 A broad upper level trough will remain over the Pacific Northwest on Monday and Tuesday, followed by upper level ridging Wednesday through Friday. A 20-50% chance of showers, highest chance over the mountains, and a 10% chance of thunderstorms will continue on Monday. Precipitation chances will begin to trend lower Tuesday, then settle at around 20% over the mountains each afternoon late week with lower chances elsewhere. Ridging will bring warmer temperatures, increasing to near or slightly above normal by mid to late week. Winds will be lighter under this pattern.

AVIATION /18Z Friday through Saturday/

Issued 1126 AM MDT FRI APR 24 2026

Generally VFR with localized MVFR/IFR in isolated snow showers over the West Central and Boise Mountains this afternoon. Mountains obscured in precipitation. Surface winds: W-NW 10-20 kt with gusts 25-35 kt, strongest over the Magic Valley terminals, variable less than 10 kt overnight. Winds aloft at 10kft MSL: NW 10-25 kt shifting to SW 10-20 kt after Sat/12Z.

KBOI...VFR. Surface winds: NW 10-15 kt with gusts to 30 kt, calming to variable less than 6 kt after Sat/03Z.

Weekend Outlook...Generally VFR with localized MVFR-IFR conditions in isolated showers over high terrain each afternoon. Low confidence of thunderstorms (10-20% chance) near the NV border each afternoon. Mountains obscured in precipitation. Surface winds: variable 10 kt or less Saturday, W-NW 5-15 kt Sunday with gusts to 25 kt.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Freeze Warning from midnight tonight to 9 AM MDT Saturday for IDZ012-014-016. OR...Freeze Warning from midnight MDT /11 PM PDT/ tonight to 9 AM MDT /8 AM PDT/ Saturday for ORZ064.