Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
861 FXUS65 KBOI 240255 AFDBOI Area Forecast Discussion National Weather Service Boise ID 855 PM MDT Mon Sep 23 2024 .DISCUSSION...The warming trend continues into Tuesday as an upper ridge moves into the region. Dry conditions prevail with clear or mostly clear skies and light winds. No updates. && .AVIATION...VFR. Surface winds: Surface winds: variable less than 10 kt. Winds at 10kft MSL: northeast 5-15 kt. KBOI...VFR. Variable winds less than 10 kt becoming SE by Tue/12Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Wednesday night...Continued warming through Wednesday as a Pacific upper ridge moves inland and through our CWA. High temps Wednesday will be in the mid 80s to lower 90s in the lower valleys, and upper 70s to mid 80s in the higher valleys and mountains, or about 15 degrees above normal. Upper trough from the Gulf of Alaska will push a surface cold front inland over WA and OR Wednesday, then across our northern and western CWA zones Wednesday night, and south- central Idaho just before sunrise Thursday. Southwesterly surface winds ahead of the front will increase to 20-30 mph with gusts to 40 mph in Harney and Malheur Counties Wednesday afternoon. A 10-20 percent chance of thunderstorms will develop along the front Wednesday night north of Baker/OR-McCall/ID. The frontal passage will shift winds to west or northwest, briefly gusty but not as strong as the southwest winds ahead of the front. LONG TERM...Thursday through Monday... Dry conditions are set to prevail through the weekend as ensemble guidance maintains a mean trough over most of the western US, with stronger westerlies positioned just to the north. Temperatures will cool down on Thursday to slightly above seasonal normals behind a mostly dry cold front. There is an increasing signal (40% chance) for this ridge to break down Sunday into early next week, earlier than the EPS ensemble mean fields suggest, with the potential arrival of an amplified upper trough, which would bring cooler temperatures, breezier winds, and at least low-end precipitation chances to the region. && .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.....BW SHORT TERM...LC LONG TERM....JR