Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
013 FXUS65 KBOI 051526 AFDBOI Area Forecast Discussion National Weather Service Boise ID 926 AM MDT Wed Jun 5 2024 .DISCUSSION...No forecast changes at this time. Saturday still looks the hottest day with the upper ridge axis right overhead. We have around 25% chance of reaching 100F at Boise that day with Ontario/OR having a 55-60% chance. Thunderstorm chances will increase Thursday and Friday afternoons especially in southern areas. Beginning Sunday most models begin a cooldown as a north Pacific trough moves onto the northwest coast. ECMWF, however, maintains the ridge several more days. But even longer- range ECMWF does show a deep upper trough and much cooler air arriving by the end of next week. && .AVIATION...VFR conditions today. High pressure dominating and just a few clouds. Surface winds: W 5-15 kt, with gusts 20-25 kt south-central Idaho including the Magic Valley terminals. 10kft MSL winds: W 20-35 kt. KBOI...VFR. A few high level clouds. Surface winds becoming NW 5-10 kt, then southeast 5 kt or less after 03Z. && .PREV DISCUSSION... SHORT TERM...Today through Thursday night...An upper level ridge will build into the region through the short term period, bringing the hottest temperatures of the year. Today will be clear, hot, and dry with some high clouds building in over southeast Oregon by later this evening. Temperatures will be about 15 degrees above normal with locations in the Lower Treasure Valley reaching the upper 80s by the afternoon. Diurnal winds will remain light and variable throughout most of the region, with increasing westerly winds by the afternoon in the Lower Snake Plain. Some mid-level moisture along with some shifting southwest flow will bring a chance for thunderstorms near the Nevada border on Thursday night. The High Resolution Ensemble Forecast (HREF) gives about a 60% chance of a thunderstorm over the border of Owyhee County, ID with Nevada. Gusty winds are likely with any storms that form, especially given the hot and dry conditions. LONG TERM...Friday through Tuesday...The ridge will continue to build over the region through the weekend, with the hottest temperatures of the week expected to be on Saturday. Temperatures will be about 20 degrees above normal, with highs in the upper 90s in area valleys. Another pulse of mid level moisture will allow for a slight chance of showers and thunderstorms in southeast Oregon and near the ID-NV border on Friday night. A better chance for showers and thunderstorms looks to be on Saturday into Sunday as the ridge leaves the region and southwesterly flow with a preceding weak cold front begins to make way into the area on Sunday morning. After Sunday morning, significant model uncertainty persists for the beginning of next week. Most of the cluster ensembles show the ridge continuing into next week, while deterministic models show zonal flow moving in and cooling temperatures down while bringing a chance of precipitation. Regardless of the upper level flow that is realized, temperatures will likely moderate significantly compared to earlier in the week with a low chance of high terrain showers on Monday night into Tuesday. && .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...LC AVIATION.....MC SHORT TERM...SA LONG TERM....SA