textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Gusty winds this afternoon in south-central Idaho, including the Western Magic Valley and Camas Prairie. - Valley rain and mountain snow generally above 6000-7000 feet in Baker County, OR and the Central ID Mountains through early Sunday.

- Strong wind with widespread precipitation and low chance of a stray thunderstorm on Saturday along and behind a cold front. - Record to near record high temperatures over much of the region next Tuesday through at least Thursday. Monthly record highs for March will also be threatened in some locations.

SHORT TERM /Through Saturday Night/

Issued 227 PM MDT THU MAR 12 2026 Elevated winds are occurring in south central Idaho, with Twin Falls and Jerome gusting to 40 mph this afternoon. Gusts will continue, with periods of gusts up to 45 mph, until sunset. The atmospheric river to our north is transporting significant moisture over northern Valley County, with mountain snow showers and valley rain expected to continue through the short term period. Rainfall will be highest in mountain zones northeast of the Snake River Valley, with up to one inch of liquid equivalent over the highest terrain by Saturday. Snowfall totals by late Saturday will range from a dusting to 2 inches over mountain valleys, with an additional 8 to 12 inches of wet snow over 6000-7000 feet.

A cold front will move through the region on Saturday, bringing much colder temperatures, a brief switch to snow for mountain valley floors, and very strong winds. There is a low chance (<10%) that this cold front could bring embedded convection, although forecast guidance shows minimal instability along and ahead of the front. If any of these stronger showers or thunderstorms form, isolated gusts up to 60 mph could occur.The high wind watch has been trimmed from this morning's package to cover the Snake Plain and southeast Oregon, with ID mountain zones generally being sheltered from the strongest wind gusts thanks to the terrain. Ridgetops will still see strong winds, but valley winds are anticipated to be much lower in the Lower Treasure Valley, Upper Weiser Basin, and West Central-Boise Mountain zones. Sustained winds in the areas with a high wind watch are anticipated to reach 30-40 mph with gusts up to 55 mph.

LONG TERM /Sunday through Thursday/

Issued 227 PM MDT THU MAR 12 2026 Sunday will be cool on the backside of an upper level trough. Highs will be around 5 degrees below normal with mostly dry conditions. However, there will be a 30-60% chance of rain and snow in the mountains late Sunday into early Monday as the fringe of an atmospheric river rotates around an upper level ridge and into northern Idaho. Snow levels will be low (3-5kft MSL), supporting the potential for light snow accumulations in the mountains. Much of southeast Oregon, the Snake Basin, and points south should remain dry.

A much warmer pattern will develop through the rest of the week as an upper level ridge along the coast migrates to the east and amplifies. After around 15 degrees of warming on Monday, high temperatures will be at or near records by Tuesday. Temperatures will rise a few more degrees on Wednesday and Thursday. Lower valleys will reach the 70s to lower 80s, which will challenge not only daily record high temperatures, but also monthly high records for March. A minimal (20%) chance of showers will exist across the northern mountains by midweek if the ridge axis moves slightly to the east, allowing limited moisture to move in under southwesterly flow aloft. Aside from breezy conditions on Monday across south- central Idaho, winds will be fairly light through the period.

AVIATION /00Z Friday through Saturday/

Issued 523 PM MDT THU MAR 12 2026

Generally VFR with mid to high clouds. Periods of precipitation over the central ID mountains and NE Oregon resulting in periods of MVFR conditions and mtn obscuration. Areas of LLWS overnight but generally under 30 kt. Snow Levels: 6-7.5kft MSL. Surface winds: Generally NW-SW 5-15 kt with gusts to 20-30 kt near KBNO/KJER/KTWF this evening, gusts decreasing overnight. Winds aloft at 10kft MSL: W 45-55 kt.

KBOI...VFR under mid-high clouds. LLWS overnight, although generally under 30 kt. Surface winds: Becoming E-NE 5-10 kt overnight, then NW 7-12 kt with gusts to 18 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. Wind Advisory until 7 PM MDT this evening for IDZ016-028-030. OR...High Wind Watch from Saturday afternoon through Saturday evening for ORZ061>063.