textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

-Valley rain and mountain snow through Wednesday. Northwest winds gust up to 30 mph during the day and isolated afternoon thunderstorms are possible.

-The most impactful system arrives late Wednesday, bringing a strong cold front with gusty winds and heavy mountain snow into Thursday morning. Gusts of 30-45 mph possible across eastern OR ahead of the front. Significant snow is expected above 6000 feet, with snow-covered roads across portions of Idaho Highway 55, ID Highway 21 and US 95 Thursday morning.

-Dry weather and above normal temperatures return for the weekend.

SHORT TERM /Through Thursday Night/

Issued 405 AM MDT TUE MAR 31 2026 A stationary front remains over the area over the next day with shower chances highest north of a line from Burns to Boise. Snow levels remain around 6500-7500 feet today. A trough will slowly move into the region, ushering in cooler air aloft by Wednesday. This cooler air will generate enough instability for showers and isolated thunderstorms during the afternoon each day. Relatively dry low levels will support gusty outflow winds in the vicinity of showers. Snow levels fall to 5500-6500 feet on Wednesday.

Winds will ramp up ahead of a cold front Wednesday afternoon, especially in eastern OR, with gusts of 30 to 45 mph. Hazy conditions from lake dust across southcentral OR is possible.

A potent cold front will move into the area early Thursday morning, with snow levels falling to around 2500-3000ft. Moderate to heavy showers with a slight chance of thunderstorms expected along the front. Little to no snow accumulations in the valleys below 4000 feet, 2 to 6 inches above 5000 feet, and 6 to 10 inches of snow above 6000 feet. Precipitation quickly tapers off behind the main front with scattered showers during the afternoon on Thursday.

LONG TERM /Friday through Tuesday/

Issued 405 AM MDT TUE MAR 31 2026 The upper low system is expected to steer eastward out of our area and continue a weak northwest flow through Friday. Precipitation chances will begin to taper off with scattered snow showers continuing over higher terrain through Friday afternoon. Come Saturday, a drying and warming trend will set in as a Pacific ridge builds into the northwest region. Through Sunday, temperatures will be up to 5-10 degrees above normal. On Monday, another upper low off the Gulf of Alaska will potentially steer a shortwave trough across the northern portions of our CWA. Considerable guidance uncertainty remains over the timing and magnitude of this system. For now, a less than 20% chance of precipitation is expected for mountain areas on Monday and up to 30% on Tuesday.

AVIATION /18Z Tuesday through Wednesday/

Issued 1147 AM MDT TUE MAR 31 2026 Showers increasing across the area, bringing MVFR-IFR in mountains and near KONO. A 20-30% chance of thunder north and west of KMUO exists this afternoon as showers strengthen. Small hail/graupel are likely out of thunderstorms. Shower activity decreases tonight before more rain moves in tomorrow. Surface winds: becoming SW-NW 5-15 kt, gusts up to 30 kt possible near storms. Winds aloft at 10kft MSL: SW 25-35 kt.

KBOI...VFR and overcast. Rain showers increase this afternoon with a 30% chance of thunder. Thunderstorms could produce small hail/graupel and wind gusts up to 25 kt. Surface winds: light and variable, staying generally SW-SE.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.