textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Gusty westerly winds tomorrow afternoon and Saturday, especially over ridgetops and in the Magic Valley-Camas Prairie. - An atmospheric river to our north will bring valley rain and wet mountain snow to Baker County, OR and Central ID Mountains through Sunday, with heavy snow accumulations above 7000 feet MSL. - Record to near record high temperatures are expected over much of the region next Tuesday and Wednesday. Monthly record highs for March will also be threatened in some locations.

SHORT TERM /Through Friday Night/

Issued 244 PM MDT WED MAR 11 2026 Zonal flow aloft will continue to bring moisture to higher elevations across the northern tier of our CWA (West Central Mountains to Baker County, OR). Light snow showers are occurring in McCall as of 2 pm MDT, with minor accumulations of less than one inch expected by nightfall. Moisture from an atmospheric river to our north will continue to bring ample valley rain and mountain snow to high terrain north of the Snake River Valley and over Baker County, with over an inch of liquid precipitation by Friday night. Snow levels will start around 4500-5500 feet MSL today, but warm air advection from the high to our south will increase them to 6500-7500 feet MSL by tomorrow. The highest snowfall will generally be limited to elevations above 7000 feet MSL, with anywhere from 10-20 inches of snow expected for these high elevations by Saturday morning. Snow to liquid ratios (SLR), which is a measure of the density of water in snow, will be low (less than ten inches of snow to one inch of water) through the end of the short term period. Therefore, accumulations at these higher elevations will be heavy and wet.

Breezy to gusty winds will accompany zonal flow through the short term period. Gusts up to 50 mph are expected tomorrow afternoon in the Magic Valley, Camas Prairie, and areas near the Nevada border, with a wind advisory in effect for these locations for tomorrow from 1-7pm MDT. Temperatures will be near normal today, warming to about 5 degrees above normal by Saturday. Valley highs will remain in the 60s beginning tomorrow.

LONG TERM /Saturday through Wednesday/

Issued 244 PM MDT WED MAR 11 2026 Saturday will feature strong westerly to northwesterly flow and a cold front, driven by a shortwave trough moving across northern Idaho. This will bring gusty winds to the region, with at least a 50% chance of gusts greater than 45 mph across much of the area. The exceptions will be Boise and points to the north and west as well as sheltered mountain valleys, where chances will be lower to see gusts that strong. The cold front will also bring rain and snow to the area, with the highest chance of precipitation in the morning. Any rain amounts in lower elevations will be light as the moisture tap quickly fades as the trough passes through. The mountains will see a few more inches of snow above 4000-6000 feet. An upper level ridge will move onto the coast on Sunday, putting our area in a cool northwest flow aloft. A plume of moisture moving over the ridge will continue a chance of rain and snow, mainly over the mountains Sunday into early Monday. Temperatures will dip from slightly above normal on Saturday to slightly below normal on Sunday. Winds Sunday and Monday will be breezy, especially across the Magic Valley, but will be weaker than on Saturday.

Late Monday through Wednesday, the ridge will move east and amplify. As a result, temperatures will warm 10-15 degrees from Sunday to Monday, another 5-10 degrees on Tuesday, and a few more degrees on Wednesday. By Tuesday, high temperatures will be at or near record highs across the area. On Wednesday, lower elevations across the Treasure and Magic valleys have a 50-80% chance of reaching 80 degrees. For Boise, there is a 70% chance this occurs, which would be the earliest 80 degree day on record. Monthly record highs for March will also be threatened in some locations. The unseasonably warm temperatures may last a couple more days beyond Wednesday before the next pattern shift.

AVIATION /00Z Thursday through Friday/

Issued 544 PM MDT WED MAR 11 2026

Generally VFR. Showers across the central ID mtns continuing overnight, resulting in localized MVFR/LIFR conditions. Mtns obscured in precip. Snow Levels: 4.5-7kft MSL, rising to 6-8kft MSL by Thursday afternoon. Surface winds: SW-SE 5-15 kt with gusts to 20-30 kt outside of the lower Snake Basin overnight. Becoming W-NW 10-20 kt with gusts to 10-35 kt Thu/PM, highest near KJER/KTWF. Winds aloft at 10kft MSL: W 45-55 kt.

KBOI...VFR under mid to high clouds. LLWS overnight through early Thursday morning. Surface winds: SE 8-12 kt overnight. Becoming W-NW 10-15 kt Thur/AM with gusts to 25 kt Thur/PM.

BOI WATCHES/WARNINGS/ADVISORIES

ID...Wind Advisory from 1 PM to 7 PM MDT Thursday for IDZ016-028- 030. OR...None.