Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
426 FXUS65 KBOI 060246 AFDBOI Area Forecast Discussion National Weather Service Boise ID 846 PM MDT Sun Oct 5 2025 .DISCUSSION...Clear skies and diminishing winds tonight will create ideal conditions for radiational cooling across the area, leading to a chilly night. The most significant impacts are expected in the Western Magic Valley, where a Frost Advisory is in effect for temperatures forecast to drop into the low to mid 30s. While higher elevation valleys have a high probability of reaching freezing temperatures, the Treasure Valley will likely remain slightly warmer, with lows in the upper 30s. A warming trend is forecast to begin Monday, bringing abundant sunshine and warmer afternoons through at least the middle of the week. && AVIATION...VFR. Skies mostly clearing with some mid-to-high clouds over E`rn OR. Snow levels 6000-7000 ft MSL. Patchy valley fog and scattered low stratus clouds overnight, primarily in sheltered mountain valleys (near KMYL). Surface winds: NW-NE 5-15 kt, with gusts up to 20 kt through the Snake Plain becoming variable less than 10 kt tonight after 05Z. Winds aloft at 10 kft MSL: N-NE 5-15 kt. KBOI...VFR. Surface winds: NW 5-10 kt, shifting to SE 5-10 kt tonight after 05Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Tuesday night...Breezy northwesterly winds are kicking up across the Snake River Valley this afternoon, with cool temperatures and a few cumulus clouds building over higher terrain. Isolated showers with a stray lightning strike will continue over the Southern Boise Mountains, dissipating after 6pm MDT. Clouds will begin to clear overnight, with temperatures reaching near or below freezing in higher elevation valleys. Therefore, a frost advisory has been issued for the Western Magic Valley with overnight lows anticipated to be around 30-37F. Winds will die down quite a bit overnight, with patchy fog likely in sheltered valleys. Fog will mix out by mid morning, with another day of cool and dry conditions anticipated. A Pacific high will then build in on Tuesday, with temperatures increasing across the region. LONG TERM...Wednesday through Sunday...Dry southwesterly flow will bring warming and drying conditions through Thursday. Temperatures will climb to about 3-5 degrees above normal through the midweek, then a return to a cool and wet pattern will occur. Model agreement has increased with ensembles agreeing on the track of a deep upper level low moving into the Pacific Northwest on Friday, bringing cooler temperatures, gusty winds, and high terrain showers to the area. There is still large discontinuity on the timing of the heaviest precipitation, with the GFS/Canadian deterministic models showing a much slower evolution compared to the ECMWF. By Sunday, the trough axis will move east, bringing cold temperatures and lingering showers over higher terrain. This will be a much colder air mass than earlier this weekend, so there is a potential for light snow down into population centers in mountain areas like McCall and Idaho City on Sunday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Frost Advisory from 2 AM to 10 AM MDT Monday IDZ016. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...JDS AVIATION.....JY SHORT TERM...SA LONG TERM....SA