Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
384 FXUS65 KBOI 020256 AFDBOI Area Forecast Discussion National Weather Service Boise ID 856 PM MDT Fri Aug 1 2025 .DISCUSSION...There are a couple areas of ongoing convection (showers/thunderstorms) this evening, one is over the southern ID highlands and the other is in western Harney County. Both are aided by weak short waves moving through a southwest flow aloft. The trend is for a decrease in strength and coverage through midnight, but there is a slight chance (less than 20 percent) of lingering showers in s-central ID after midnight. There is a 15-30 percent chance of more showers and thunderstorms over the higher elevations Saturday afternoon and evening. No updates. && .AVIATION...Mostly VFR. Isolated showers/thunderstorms near the Magic Valley and KBNO this evening, with about a 30% chance of storms continuing briefly this morning. Low confidence in afternoon showers and thunderstorms tomorrow, mainly over SE OR and the Magic Valley. Thunderstorms capable of heavy rain, small hail, 30-40 kt outflows, and brief MVFR conditions. Mtns obscured in precip. Surface winds outside of outflows: variable less than 10 kt overnight becoming W-NW 8-12 kt by 02/16Z. Winds aloft at 10kft MSL: S-SW 10-20 kt. KBOI...Mostly VFR with some haze aloft from OR wildfires. Surface winds: W-NW 5-12 kt becoming NW 10-12 kt by 02/16Z. Sunday Outlook: Isolated showers/thunderstorms across Baker County, Magic Valley, and higher terrain in SW Idaho Sunday. Thunderstorms capable of 30-40 kt outflows, and heavy rain resulting in MVFR conditions and mountain obscuration. Surface winds outside of outflows: NW-SW 5-15 kt each afternoon, variable 5-10 kt over nights. && .PREV DISCUSSION... SHORT TERM...Tonight through Sunday night...We`ll see another round of showers and thunderstorms on Saturday. The focus of develop will be across SE Oregon and SW Idaho south of the Snake Plain as a minor wave tracks through the northern Great Basin. A slightly warmer and drier air mass near the surface will increase the outflow wind gust threat up to 50 mph, compared to today`s 30-40 mph potential while a weak shear environment will result in mostly short-lived smaller storms. A deeper upper trough and surface front will approach the region on Sunday placing SE Oregon in a favorable position for shower and thunderstorm development. A more robust environment ahead of the trough would increase the chance for stronger thunderstorms to develop. Southeast Oregon will see its somewhat common late afternoon/evening wind push which will likely be enhanced by the cold front and outflow from upstream showers/storms Sunday evening. Typically windy locations, to include the I-84 corridor in Baker County along with northern Harney and Malheur counties will see stronger winds Sunday evening. Temperatures are at or slightly below normal through Sunday, even as the average temperatures starts to drop after today. Smoke will hang around with varying coverage. LONG TERM...Monday through Friday...High guidance confidence remains over a shortwave trough digging across the Pacific Northwest and Upper Great Basin through Monday. Isolated showers/thunderstorms are expected to continue Monday, mostly over Eastern OR and West- Central ID. The frontal passage is also expected to bring a cooling trend on Monday, dropping peak valley temperatures into the lower to mid 80s and mountain temperatures into the 60s/70s. Tuesday and Wednesday will see a large high pressure ridge over the Four Corners region build into the area, returning a warming and drying trend. Tuesday will see valley daytime temperatures climb back up into the upper 80s and Wednesday into the lower 90s. Guidance uncertainty remains over a longwave trough moving into the Northwest region on Thursday and Friday. For now, conditions are tentatively on the warmer and drier side towards the end of the extended forecast period. && .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...BW AVIATION.....SA SHORT TERM...DG LONG TERM....JY