Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
821 FXUS65 KBOI 281533 AFDBOI Area Forecast Discussion National Weather Service Boise ID 933 AM MDT Thu Aug 28 2025 .DISCUSSION...A relatively mundane morning after the record PW`s, this morning`s sounding had 0.99 inches of PW which is ONLY at the 95th percentile instead of threatening the 100th. That being said, there`s still enough moisture for some instability and isolated storms this afternoon and tomorrow afternoon. They will develop in SE OR, the ID/NV border, and W-central ID, with gusts up to 40 mph and rainfall possible. As we begin to dry out, rainfall becomes less of a concern and wind becomes more of a concern. This weekend is looking to become much drier, with chances for precipitation diminishing on Saturday. We`ll also begin to warm up back to normal temperatures. && .AVIATION...Patchy LIFR fog at a few sites is actively dissipating, though haziness from wildfire smoke persists. Generally VFR through the day, with isolated thunderstorms in SE OR and W-central ID Mtns this evening. Thunderstorm gusts up to 35 kt are possible. Surface winds: Variable 5-10 kt this morning becoming 5-15 kt SW-NW. Winds aloft at 10kft MSL: W-NW 5-20 kt. KBOI...Mainly VFR and hazy due to wildfire smoke. Surface winds: SE 5-8 kt becoming W-NW 8-12 kt or less by Thu/18Z. Weekend Outlook...VFR conditions. Winds E-SE 5-10 kt. Mostly clear skies with some high clouds approaching E`rn OR Sunday afternoon/evening. && .PREV DISCUSSION... SHORT TERM...Today through Saturday night...The plume of deep monsoon moisture that`s been in place over the region for past few days is being pinched off and lifted northward this morning. While weak upper ridging brings drier air to the region today and Friday we won`t completely get rid of the shower and thunderstorm threat. Afternoon heating/instability will support cumulus buildups and a 20% chance of showers and thunderstorms across SE higher and higher terrain south of the Snake Plain in Idaho this afternoon. The area expands to cover the w-central Idaho mtns on Friday. The drier air mass and a weak shear environment will shift the main storm attribute to gusty outflow winds both days. The upper ridge amplifies over the area on Saturday, bringing further drying and more stable conditions aloft which will cap any threat for afternoon showers/storms. A more westerly flow aloft through Friday will transport elevated smoke to the area from wildfires in w-central Oregon, making for hazy skies. Temperatures return to normal by Friday, placing high temperatures around 90 degrees at lower elevations. LONG TERM...Sunday through Thursday...A broad upper ridge off the Desert Southwest will continue building into our area through Sunday. A slight warming trend will continue Sunday through Thursday, with valley daytime temperatures expected to linger in the lower 90s and central mountain daytime temperatures in the upper 70s/lower 80s. Monday through Thursday will see an upper low stalling and wobbling off the Pacific Northwest coast and slowly shift back out Northwest. This odd troughing pattern has the potential to steer weak upper moisture into the area from the coast of California. For now, the highest chances of showers/thunderstorms remain over the higher elevations along the Easternmost side of the forecast area and along the ID-NV border. Otherwise, mostly dry and warm conditions will persist throughout the extended. && .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...JM AVIATION.....JM SHORT TERM...DG LONG TERM....JY