Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
175 FXUS65 KBOI 040246 AFDBOI Area Forecast Discussion National Weather Service Boise ID 846 PM MDT Tue Jun 3 2025 .DISCUSSION...o forecast changes. Northwest flow aloft will continue through Friday between an upper ridge in the eastern Pacific and a broad upper trough centered roughly over the Rocky Mountains. Both the ridge and trough will shift slowly eastward resulting in steady warming (4-6 degrees per day) and decreasing northwest winds. Hottest days should be Monday and Tuesday when the upper ridge passes directly overhead. High temps on those days should reach 95 to 100 degrees in our lower southern valleys. As the Pacific ridge moves eastward a weak upper low in the desert southwest will be shifting westward, and mid/high level moisture will gradually increase in the Great Basin. This will lead to a 10-20 percent chance of high- based thunderstorms in our southern areas on the hottest days. Longer range models show a cooldown next week as an upper trough from the Gulf of Alaska replaces the upper ridge. && .AVIATION...VFR. Surface winds: N-NW 10-20 kt with gusts up to 18-28 kt this evening, becoming variable 5-12 kt after sunset. Winds aloft at 10kft MSL: N-NW 10-20 kt. KBOI...VFR. Surface winds: NW 10-15 kt gusting to 25 kt this evening. becoming variable under 10 kt overnight. && .PREV DISCUSSION... SHORT TERM...Tonight through Thursday night... The forecast area will remain under the influence of dry northwest flow as a strong upper level ridge remains situated off the coast while an upper trough extends from the northern plains across the Great Basin. The pressure gradient will relax tomorrow resulting in considerably less wind while temperatures begin an upward trend. Other than some passing high clouds and diurnal cumulus over the higher terrain, mostly sunny/clear conditions will prevail. LONG TERM...Friday through Tuesday...A strong upper level ridge will build into the northwest region Friday and through the weekend. This ridging is expected to bring hot temperatures across the area later in the weekend from Sunday to Monday, with a 5-10% chance of 100 degree high temperatures in the lower valleys for both days. On Monday and Tuesday, long-range guidances generally indicate a weak trough moving onto the northwest coast. There is considerable uncertainty over the timing and magnitude of this trough early next week, but current guidances project a slight (10- 20%) chance of afternoon showers and thunderstorms to the area on Monday and Tuesday, mostly in higher elevations. Breezy afternoon winds are generally expected throughout the long-term 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...LC AVIATION.....NF SHORT TERM...TL LONG TERM....JY