textproduct: Boise

UPDATE

Updated aviation discussion.

KEY MESSAGES

- Dry and mild Sunday, then cooler with increasing winds, clouds and precipitation chances on Monday.

- Gusty afternoon winds in the extended, particularly Tuesday afternoon and Thursday afternoon.

SHORT TERM /Through Monday Night/

Issued 251 PM MST SAT MAR 7 2026 The upper ridge will flatten out on Sunday as strong westerly flow pushes in from the Pacific. The area remains on the warm side of the jet which will result in high temperatures reaching well into the 60s across lower elevations, and around 50 degrees in mtn valleys. Winds will become breezy across higher terrain where better vertical mixing is expected. Winds will generally top out between 15-20 mph with gusts to 30 mph in these areas. A cold front will sag south through the area on Monday, bringing a return of clouds and a chance of showers across the mountains. The mountains of Baker County and w-central Idaho will see a 50-80% chance of precipitation Monday/Monday night. The chance for measurable rain/snow drops to 20-40% across the Boise Mountains, and less than 10% across SE Oregon and the Snake River Plain. Increased westerly flow behind the front will bring another round of gusty winds Monday afternoon/evening. Open terrain, including the I-84 corridor will see northwest winds gusting to 35 mph. In this pattern, the wind max aloft will favor the Camas Prairie and northern foothills of the Magic Valley with the strongest winds, where gusts to 45 mph are possible. high temperatures will run about 10 degrees cooler on Monday, or near normal for early March.

LONG TERM /Tuesday through Saturday/

Issued 251 PM MST SAT MAR 7 2026 Strong west-northwesterly flow aloft will be overhead, associated with high pressure building over the Eastern Pacific and a longwave troughing pattern over Canada with multiple embedded shortwaves. Cool air will still permeate throughout the region Tuesday from the cold front that passed previously, keeping max temperatures 10-15 degrees below normal. Models agree on the front stalling out in Northern Nevada through early Wednesday, creating a strong pressure gradient across our region. The impact from this is the strong winds and wind gusts Tuesday afternoon, mostly over south-central Idaho. From Mountain Home to the Western Magic Valley (and higher elevations), there is a 50-80% chance of gusts stronger than 30 mph. In the Camas Prairie, there is a 40-70% chance of gusts stronger than 40 mph. While the bulk of the moisture will remain north of the forecast area, a medium chance (40-60%) of light snow is forecast across northeast Oregon and west-central Idaho throughout the day.

During the afternoon Wednesday, the Pacific high sitting off the California coast builds in overhead, with cluster solutions disagreeing on intensity and amplitude. Regardless, this will bring warm air back into the area, with valley floors reaching into the upper 50s and lower 60s. Areawide, normal to above normal temperatures return by Thursday. Moisture will continue to stream into the Pacific Northwest during this time, which will maintain precip chances (30-60%) across the northern zones both days. Snow levels will rise from 1.5-3.0 kft MSL Wednesday morning to 4.5- 6.5kft MSL Wednesday evening. Windy conditions are anticipated in the afternoons, this time affecting more of southeast Oregon and central Idaho as surface flow transitions to south/southwest. Thursday afternoon will be of particular interest, with widespread wind gusts of 30+ mph chances from 50-90%. Current models shield the Treasure Valley and mountain valleys from these strong gusts, but keep them breezy. A particular forecast point of concern is the Camas Prairie again during this time.

Once Friday rolls around, significant cluster disagreement on the overhead pattern emerges, with the strength of the upper-level ridge greatly in question. Two primary scenarios exist: one is the ridge strength holds and keeps temperatures warm, or the cooler air makes another oscillation southward over the area. The NBM max temperature range on Friday for Boise is from 48 to 72 (25th percentile to 75th percentile), which highlights the uncertainty well and showcases the two different scenarios listed. These scenarios will also dictate precipitation chances, although surface winds will remain gusty regardless.

AVIATION /06Z Sunday through Monday/

Issued 1038 PM MST SAT MAR 7 2026

Mainly VFR. Low clouds bringing periods of low VFR or MVFR conditions over the west-central ID mountains and the Magic Valley overnight. Patchy IFR/LIFR fog will develop overnight into Sunday morning in lower valleys across SE Oregon and in SW Idaho west of KEUL. Surface winds: variable 10 kt or less, then SW-NW 5-15 kt Sunday afternoon with gusts 20-30 kt over higher/exposed terrain. Winds aloft at 10kft MSL: NW 15-30 kt, becoming W 20-40 kt after Sun/12Z.

KBOI...VFR. Surface winds: SE 4-8 kt, then NW 4-8 kt Sunday afternoon.

BOI WATCHES/WARNINGS/ADVISORIES

ID...None.

OR...None.