Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
465 FXUS65 KBOI 241558 AFDBOI Area Forecast Discussion National Weather Service Boise ID 958 AM MDT Mon Jun 24 2024 .DISCUSSION...Southwest flow aloft will maintain the dry and stable conditions today. Temperatures will be slightly lower compared to the weekend, but still above normal with highs in the 80s and 90s. No updates. && .AVIATION...VFR with clear skies. Reduced visibilities from smoke near a fire in far SW Idaho. Surface winds: NW 5-15 kt becoming variable less than 10 kt overnight. Winds aloft at 10kft MSL: W-SW 20-35 kt. KBOI...VFR with clear skies. Surface winds: NW 5-10 kt becoming variable less than 5 kt overnight. && .PREV DISCUSSION... SHORT TERM...Today through Wednesday night...A mild cold front passed through this morning, maintaining cooler temperatures with west-northwesterly winds across the Treasure Valley today. Afternoon temperatures are expected to range from the low to mid 90s. Higher elevations will experience westerly winds with gusts up to 20-30 mph, creating warm, dry, and breezy conditions conducive to active fire behavior. This may lead to smoke plumes and haze, particularly east-northeast of the significant fire in southwest Owyhee County. On Tuesday, a much stronger trough from the Gulf of Alaska will approach the Pacific Northwest coast, causing upper-level winds to shift south- southwest. This change will bring a return to hot temperatures. Moisture originating from the southwestern U.S. will move northward reaching the Idaho/Nevada border Tuesday evening. The moisture is high-based with minimal potential for precipitation despite some convective activity. Temperatures are forecasted to peak on Tuesday with light surface winds and mostly clear skies, with a 30-60% chance of temperatures reaching 100 degrees or higher. By Wednesday, as the trough moves further inland, high-level moisture increases across southwest Idaho. The upper- level jet stream will pass over the area, enhancing instability and shear. Precipitable water values reaching 1 inch over south- central Idaho suggest favorable conditions for high-based thunderstorm development. Model forecasts vary on exact locations of these storms, but favor higher terrain in southwest Idaho. Inverted-V profiles and strong mid-level winds indicate these storms may produce gusty outflow winds, especially within the areas of deepest moisture over south-central Idaho. Increased cloud cover and west-northwesterly winds will keep temperatures slightly cooler, around the mid 90s in the lower valleys. LONG TERM...Thursday through Monday...A trough will continue to move through the Pacific Northwest and bring in notably cooler temperatures for both Thursday and Friday. Surface winds will become breezy Thursday in the wake of the cold front, but the chance for precipitation is less than 10 percent. Dry, westerly flow will develop Friday as the trough exits toward the east, with hot temperatures returning for the weekend as an upper ridge strengthens over the Intermountain West. Models currently indicate an increase of moisture Sunday and Monday as the next Pacific trough approaches, yielding a potential (15-30% chance) for showers and thunderstorms for northeast Oregon and west-central Idaho on Sun/Mon. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...BW AVIATION.....SA SHORT TERM...JDS LONG TERM....SH