textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Wet snow overnight and Thursday morning in the Snake Basin from Mountain Home east through the Magic Valley - A strong cold front moves through the region today bringing valley rain, mountain snow, and a slight chance of thunderstorms (<20% chance) this afternoon and evening with the potential for gusty outflow winds up to 45 mph.

- Windy conditions Thursday, particularly across south central Idaho where gusts up to 50 mph are expected.

- Lingering mountain showers this weekend, with another cold front early next week bringing gusty winds and widespread precipitation.

DISCUSSION

Updated forecasts for accumulating wet snow as low as 3000 feet MSL in southwest Idaho overnight through early Thursday morning. Expecting 1-3 inches accumulation in the Snake Basin, heaviest in the Magic Valley. Roads in the basin should stay wet but may become slushy and create a travel hazard.

PREV DISCUSSION

SHORT TERM /Through Friday Night/ Issued 211 PM MST WED MAR 4 2026 The cold front is tracking through the region as of 2 pm MST, bringing cooler temperatures, moderate rain, and gusty westerly winds across the region. Temperatures have decreased around 5 to 10 degrees as the front has passed through. For example, Rome, OR dropped from 51F to 40F in the space of one hour with northwesterly wind gusts up to 45 mph.

No lightning has been observed north of the Nevada border, but a stray thunderstorm is still possible (20% chance) this evening across southwest Idaho. The outflow wind gusts ahead of the heavier showers are still the primary concern this evening, with several hi-res models showing gusts up to 50 mph along the Mountain Home to Twin Falls I-84 corridor ahead of the front. Moderate valley rain and mountain snow will accompany this push of cold air. The heaviest mountain snowfall will generally be isolated to elevations above 7500 ft, with totals anywhere from 5 to 10 inches by tomorrow morning. Lower elevations from 4000-6000 feet will likely see wet snow totals from 1 to 3 inches.

Winds will kick up behind the cold front over the Camas Prairie and Magic Valley tomorrow, bringing gusts up to 50 mph by early afternoon, therefore the wind advisory is still in effect for those southern zones for tomorrow afternoon. Showers will linger on Friday, with minor accumulations over the mountains, otherwise conditions will be dry and cool under northerly flow aloft.

LONG TERM /Saturday through Wednesday/ Issued 211 PM MST WED MAR 4 2026 This coming weekend will be mostly dry as a building ridge over the North Pacific extends into our area. This ridging will allow for a warming trend, with temperatures warming to 5-10 degrees above normal on Sunday. Saturday will feature increased high clouds as a shot of upper- level moisture works around the ridge, before clearing Sunday. This remnant moisture may bring slight chances of precipitation over mountain areas this weekend.

Come Monday, a persistent west-northwest jet stream will sit over the northwest region, breaking down the ridge and bringing a cold front across the area early next week. Upper-level moisture continues to look limited as the front steers across the Northern Cascades. However, precipitation chances will increase (to 30-70%) over our northern mountains zones thanks to some orographic lift. Snow levels will drop from 6.5-7.5 kft Sunday to be at or near valley floors following this cold front through Wednesday. For now, accumulations are limited to the central ID mountains. Gusty winds will accompany this cold front, especially Tuesday afternoon where there is a 70-80% chance of wind gusts of 30+ mph in Mountain Home and eastward through the Snake River Plain. Unsettled northwesterly flow aloft will allow for snow showers to persist over the central Idaho Mountains through Wednesday.

AVIATION /06Z Thursday through Friday/

Issued 1042 PM MST WED MAR 4 2026

Rain and snow across SW Idaho late this evening will decrease overnight, with scattered showers continuing into Thursday. A 30% chance of light snow near KJER/KTWF Thursday morning. Snow levels 3000-4000 ft MSL. Mainly VFR to MVFR, except IFR to LIFR in snow. Mountains obscured. Gradual improvement through the day Thursday. Surface winds: W-NW 10-25 kt with gusts 25-35 kt. Gusts up to 45 kt in the Magic Valley Thursday afternoon. Winds aloft at 10kft MSL: N-NW 25-40 kt.

KBOI...Light rain showers will continue overnight, tapering off on Thursday. MVFR conditions in rain and low clouds overnight, gradual improvement Thursday. A 20% chance of a rain/snow mix early Thursday morning. Foothills obscured in precip. Surface winds: NW 10-20 kt with gusts up 25 kt, increasing to 30 kt Thursday afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Wind Advisory from 11 AM to 8 PM MST Thursday for IDZ014-016- 028-030. OR...None.