Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
813 FXUS65 KBOI 250900 AFDBOI Area Forecast Discussion National Weather Service Boise ID 300 AM MDT Tue Jun 25 2024 .SHORT TERM...Today through Thursday night...Sunny and hot today as an upper ridge builds over the area. Southwesterly flow aloft will draw in mid and high level moisture from NV, CA, and AZ late today and tonight with clouds spreading over our CWA. A slight chance of thunderstorms will move north of the NV border this evening, then later tonight over nearly all of eastern OR and Idaho south of the Snake River. A better chance of thunderstorms (30 to 50%) will come Wednesday morning over the entire CWA, gradually shifting out of eastern OR Wednesday afternoon as a cold front moves through, but increasing to near 60% in southern Owyhee and Twin Falls Counties. Relatively little rain (generally less than .10 inch) will reach the ground from these thunderstorms due to dry air in the lower atmosphere, but they will produce gusty downdraft and outflow winds as well as lightning. Wednesday night will be cooler than tonight as skies clear, and Thursday will be windy and much cooler (about 15 degrees) with highs only in the mid 70s to lower 80s in the valleys and mid 60s to mid 70s in the mountains. Thursday night will be especially cool as winds die down, with lows 45 to 50 in the valleys and 35 to 45 in the mountains. .LONG TERM...Friday through Tuesday...Dry and relatively cool northwest flow will develop Friday in the wake of a trough, supporting near-normal temperatures for the day. A quick transition to much warmer southwest flow aloft is forecast Saturday as the next trough approaches the Pacific Northwest. Current models bring the accompanying cold front through E Oregon and SW Idaho late Saturday into Sunday, introducing a 15-35% chance of showers and thunderstorms for this period. Temperatures will lower several degrees from Saturday, and remain within 5 degrees of normal through at least Tuesday as troughing persists over the northwestern U.S. Breezy winds are anticipated both Monday and Tuesday due to a strengthening surface pressure gradient and enhanced mid-level flow. && .AVIATION...VFR. Hot temperatures will promote high density altitude today. Increasing mid/high level clouds this afternoon. Scattered showers and isolated thunderstorms will develop late tonight and continue through Wed afternoon, with outflow gusts of 35-45 kt possible. Surface winds: variable up to 10 kt, becoming SW-NW 5-15 kt this afternoon. Winds aloft at 10kft MSL: SW 10-20 kt. KBOI...VFR. Hot temperatures will promote high density altitude today. Increasing high clouds this afternoon, then ceilings lowering to around 10,000 ft AGL late tonight. A 30% chance of showers/thunderstorms after 26/09Z through Wed afternoon, with outflow gusts of 35-45 kt possible. Surface winds: variable up to 6 kt. Then, NW 5-10 kt this afternoon, shifting to NE around 26/00Z. && .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 SHORT TERM...LC LONG TERM....SH AVIATION.....SH