Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
743 FXUS65 KBOI 090302 AFDBOI Area Forecast Discussion National Weather Service Boise ID 902 PM MDT Wed May 8 2024 .DISCUSSION...A highly amplified pattern develops across the west over the next couple days as a retrograding low moves southwestward from the northern plains into Utah on Thursday and an offshore ridge builds into the Pacific Northwest. SE Oregon and SW Idaho will be generally dominated by the ridge, resulting in dry and much warmer conditions. However, the low in Utah will be close enough for a 15-30 percent chance of showers in far s-central Idaho on Thursday. The windy conditions over the last couple of days are not expected to return on Thursday, but it will be breezy. No updates. && .AVIATION...VFR with decreasing clouds. Sfc winds: W-N 10-20 kt with gusts to 25 kt, diminishing to 5-15 kt by 06Z. Winds at 10k ft MSL: NE 10-20 kt. KBOI...VFR with clear skies. Sfc winds: NW 10-15 kt with gusts to 25 kt, diminishing to 10 kt or less by 04Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Friday night...Continuing through Thursday, a persistent northeasterly flow aloft prevails across the region, driven by an upper-level low situated over the Northern Plains. This atmospheric setup maintains the potential for isolated showers this afternoon in areas, including the Boise Mountains, Upper Treasure Valley east of Mountain Home, Western Magic Valley, and southern Twin Falls County. Elsewhere, expect partly cloudy skies to persist into Thursday. Breezy conditions will persist across the area until early evening, particularly east of Boise from Mountain Home through Glenns Ferry, with gusts reaching up to 40 MPH before diminishing by sunset. A gradual shift towards warmer and drier conditions is anticipated as an upper-level ridge expands eastward into the northern Rockies. However, the presence of a cut-off low over the four-corners region inhibits the eastward movement of the ridge over the Intermountain West, resulting in the warmest temperatures remaining west of the divide. Thursday and Friday are expected to feature mostly clear skies and lighter winds across most of the forecast area, with the exception being south-central Idaho on Thursday afternoon, where northeasterly flow may trigger isolated showers in the Western Magic Valley and Southern Twin Falls. Temperatures are forecasted to rise to about 10 degrees above today`s highs on Thursday, which is approximately 3 to 4 degrees above normal. An additional 5 to 7 degrees of warming is expected on Friday, with temperatures reaching the upper 70s in the lower valley. LONG TERM...Saturday through Wednesday...High confidence in much warmer and drier conditions this weekend through the middle of next week as an upper ridge builds across the Pacific Northwest. High temperatures will be 5 to 15 degrees above normal during this period, with many locations reaching the 80 degree mark Sunday and Monday. Dry conditions will also prevail, with exception to weak instability developing on Sunday and Monday leading to a very low chance (5-10%) of isolated afternoon thunderstorms. && .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...JDS LONG TERM....JR