


Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
342 FXUS65 KBOI 161522 AFDBOI Area Forecast Discussion National Weather Service Boise ID 922 AM MDT Thu Oct 16 2025 .DISCUSSION...Dry conditions today as northwest flow aloft prevails behind a departing upper level low. Breezy conditions will continue this afternoon through the Snake Basin, strongest east of Boise with gusts 20 to 35 mph. Low temperatures tonight will be looked at closely especially for the agricultural valleys, as lows are forecast to dip into the mid 30s to around 40 degrees, close to frost thresholds. Additionally, winds will be lighter than last night. However, high clouds will move overhead tonight which may keep lows up a couple degrees. Forecast remains on track and no updates anticipated this morning. && .AVIATION...MVFR-LIFR Low stratus in the Magic Valley and patchy fog in SE OR expected to dissipate later this morning. Skies generally clearing to VFR this afternoon. Valley fog formation possible again tonight. Surface winds: W-NW 5-15 kt with brief local gusts to 20 kt. Winds aloft at 10kft MSL: N-NW 10-20 kt. KBOI...VFR with mostly clear skies. Surface winds: W-NW 5-10 kt, with gusts 15-20 kt possible this afternoon. Weekend Outlook...Mostly clear conditions Friday through Saturday. Sunday clouds increase with widespread precip moving in after Sun/10Z from NW to SE lasting through the day. Best chance for precip is in the north. Snow levels during precip drop from 9 kft MSL Sun morning to 6 kft MSL Sun evening. Winds NW 5-15 kt Fri, S-SE 5-15 kt Sat, and SW-SE 5-15 kt with gusts up to 25-30 kt Sun. && .PREV DISCUSSION... SHORT TERM...Today through Saturday night...Isolated showers continue across portions of south central Idaho this morning, mainly south of the Snake River plain. This activity is expected to end by sunrise as the low moves east. Clearing skies are expected today, though temperatures will remain around 5 degrees below normal under dry northwest flow aloft. Afternoon wind gusts of 20 to 35 mph will be common across the Snake Basin, with the strongest winds east of Boise. Light winds and clear skies tonight should allow temperatures to fall into the mid to upper 30s in the western Snake River Plain. At the moment, most valley locations look to remain at or just above 36 degrees Friday morning, with the ensembles showing only a 10 percent chance of temperatures below 36 degrees (the frost threshold) across the Boise Metro area. On Friday, northwest flow aloft will continue as a shortwave trough moves by to the north, which will keep winds breezy during the day. Temperatures will warm a few degrees, but remain a couple degrees below normal. Overnight lows will be slightly colder with lighter winds, allowing sheltered areas in the agricultural valleys to dip into the low to mid 30s. Ensembles suggest a 40 percent chance of low temperatures reaching 36 degrees or colder. Due to this increasing risk, the potential for frost will be monitored closely, as a Frost Advisory may be warranted for Saturday morning. The upper level ridge rebuilds back across the Pacific Northwest on Saturday, with temperatures warming to near normal. LONG TERM...Sunday through Thursday...There is now stronger agreement between the long-range guidances on a longwave trough digging across the Northwest region on Sunday. Widespread precipitation will be expected throughout the area on Sunday, with the heaviest episodes expected through the afternoon hours. This pattern will bring a cooling trend, dropping snow levels down into the 5000-6000 ft range late Sunday into early Monday. As such, snowfall and mixed wintry precipitation remains highly probable over higher elevations through early Monday. This cooldown will drop peak temperatures from the mid 60s Sunday down into the mid to upper 50s Monday and Tuesday for most locations in the area. From the later hours of Monday through the end of the extended period, a broad upper ridge is expected to build and linger over the area, bringing a slight drying and warming trend. A weak shortwave trough is expected to break off the British Columbia coast and dig quickly across the OR/ID central mountains on Wednesday, but is expected to be dry and weak. Peak daytime temperatures are expected to slowly trend back up into the lower to mid 60s for most locations Wednesday through Thursday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...ST AVIATION.....JM SHORT TERM...JDS LONG TERM....JY