textproduct: Boise

KEY MESSAGES

- Light rain and high-elevation snow in northern mountains through Saturday night.

- High-winds and strong cold front shaping up for Saturday.

- Much colder but less windy Sunday.

- Rapidly warming Monday leading to record high temperatures area-wide Tuesday through Friday.

SHORT TERM /Through Sunday Night/

Breezy and mild again today and tonight, with light rain and high- elevation snow continuing in northern-most mountains. Pcpn will increase tonight in Idaho north of the Snake Basin, but other areas in our CWA should stay dry, although cloudy.

Saturday looks increasingly likely to bring an impactful high-wind event as models continue to bring an intense impulse inland within already strong WNW-ly flow aloft over the north Pacific. Latest models target southern Idaho for strongest winds while decreasing the winds slightly in eastern Oregon. Our High Wind Watch will continue as previously issued until we can better determine exactly where to upgrade to High Wind Warning. The Snake Basin east of Boise and south to the Nevada border are presently of greatest concern. Strongest winds should occur during and after passage of a cold front around mid-day Saturday, and through the afternoon. The overall pattern looks increasingly similar to the pattern that brought the windstorm of December 17, 2025. In addition, models continue to increase the thermal contrast across the cold front, i.e., frontogenesis, with snow level lowering all the way to valley floors late Saturday night as pcpn ends. Total pcpn through Saturday night should be .30 to .80 inch water equivalent in the West Central Idaho Mountains and Boise Mountains, .10 to .30 inch in Baker County and the Camas Prairie, and less than .10 inch elsewhere, but all areas should get wet, even if only briefly, as the cold front passes. Total snowfall should be 6 to 12 inches above 5500 feet MSL in the Idaho mountains north of the Snake Basin. McCall will have rain during most of the event, changing to snow only near the end, with less than one inch snow accumulation.

Sunday will be clearing and 15 to 20 degrees colder than Saturday, but the cold weather will be brief as a Pacific upper ridge will soon build inland, with a warm front and light pcpn again in northern areas Sunday night, followed by clearing and rapidly warming Monday on the way to record high temperatures Tuesday and beyond.

LONG TERM /Monday through Friday/

As an upper level low moves well east of the region, high pressure building over California rules the rest of the long term. Monday, a 20-30% chance of precipitation across the north turns to rain as snow levels rise to 7-8 kft MSL by that evening. Gusts in the Magic Valley and Upper Snake Plain will be 25-35 mph in the afternoon. The strong, moist flow driving the precip and gusts moves north by Tuesday, kicking off our period of near record temperatures. Monday will be 15 degrees warmer than Sunday, and about 5-10 degrees above normal for this time of year. Tuesday, temps rise to about 20 degrees above normal, threatening daily high temperature records for a toasty St. Paddy's day. Wednesday through Friday temps hold steady at 20-25 degrees above normal. Each day's daily records will be threatened, monthly max temps threatened, and we may set the record for our earliest 80 degree day in Boise on Wednesday. During this warm period, winds remain mild, afternoon RH values are 20-30% in lowlands and 30-50% in mountains, and skies are partly cloudy. The moist flow to the north of the area stays close enough to bring a 10-20% chance of rain showers across northeast Oregon and north-central Idaho. While cloudy conditions may limit daytime heating in these areas, temps will still be unseasonably warm.

AVIATION /06Z Friday through Saturday/

Issued 1052 PM MDT THU MAR 12 2026

Generally VFR under mid to high clouds. Periods of precipitation over the central ID mountains through Friday, resulting in periods of MVFR/IFR conditions and mtn obscuration. Areas of LLWS overnight, but generally under 30 kt. Snow Levels: 6-7.5kft MSL. Surface winds: Variable up to 12 kt overnight, becoming W-NW 10-20 kt with gusts to 20-30 kt Late Sat/AM. Winds aloft at 10kft MSL: W 40-55 kt.

KBOI...VFR under mid to high clouds. LLWS overnight, although generally under 30 kt. Surface winds: light and variable, leaning NE overnight. Then W-NW 10-15 kt Fri/PM.

Weekend Outlook...On Saturday, a cold front will bring heavier rain and snow to the central Idaho mountains, especially in the morning, with light precipitation elsewhere. Windy on Saturday along and behind the front. Precipitation decreasing Saturday night, drier on Sunday. Areas of MVFR/IFR and mountain obscuration in precipitation, otherwise VFR. Snow level lowering to 4-6kft MSL Saturday behind the front. Surface winds: W-NW 20-30 kt with gusts to 45 kt Saturday, W-NW 5-15 kt Sunday.

BOI WATCHES/WARNINGS/ADVISORIES

ID...High Wind Watch from Saturday afternoon through Saturday evening for IDZ014>016-028>030. OR...High Wind Watch from Saturday afternoon through Saturday evening for ORZ061>063.