Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
004 FXUS65 KBOI 260245 AFDBOI Area Forecast Discussion National Weather Service Boise ID 845 PM MDT Sat May 25 2024 .DISCUSSION... Shower activity across east-central Oregon into the west-central Mountains has mostly diminished this evening, as an accompanying shortwave has shifted well to the southeast over Utah. Dry northwesterly to northerly flow is present across most of the region, with intermittent gusts reported over the lower Treasure Valley and Magic Valley. Winds will weaken overnight area-wide. Precipitation chances are near-zero across the region for at least the next 24 hours as mid-level height rises occur. && .AVIATION...VFR through late Sunday. Showers decreasing through late evening with clouds clearing overnight. Surface winds: NW winds 10-15 kt becoming light and variable overnight. SW winds gusting to 25 kt at KTWF/KJER after 26/16Z. Winds aloft at 10kft MSL: W 10-20 kt. KBOI... VFR through late Sunday. A few gusts Sunday afternoon near 15 kt. && .PREV DISCUSSION... SHORT TERM...Tonight through Monday night...As an upper level low departs the area to the east, relatively dry NW flow aloft will move over the region tonight. The flow will slowly become west Sunday night, then southwest Monday, as a strong and large upper level low strengthens off the coast. A chance of showers and thunderstorms will continue in eastern Valley County this evening, after which we should be dry through Monday night. Temps will warm up to just a few degrees below normal Sunday and then 5-10 degrees above normal Monday. Winds will be breezy out of the NW this evening (gusts 20-30 mph common in most areas, with gusts 30-40 mph in the western Magic Valley), then settle down into typical diurnal winds through Monday night. LONG TERM...Tuesday through Saturday...The upper level low off the coast will begin to move inland Tuesday, with the trough axis moving onshore late Tuesday afternoon or Tuesday evening. SW flow ahead of the trough will advect warm air into the region Tuesday, and highs are forecast to be around 10 degrees above normal (mid to upper 80s for lower elevations). Models are in excellent agreement with the forecast through Thursday, so it is with higher-than-normal confidence that we can forecast the trough to move through our area Wed night. Showers and thunderstorms are forecast to precede the trough beginning Tuesday aft/eve in most areas (50-80% chance in the mountains, 20-30% in lower elevations). A cold front will move through Tuesday night, bringing gusty NW winds. Additional showers and storms are forecast Wed aft/eve as the trough moves overhead. There`s a 20-30% chance of showers across the higher terrain in the northern part of the CWA Thursday as cold air aloft should promote weak convection. Friday and Saturday are expected to be dry due to an upper level ridge approaching from the west. Models disagree on the amplitude of this ridge, so we are confident that temps will warm back up some, but confidence is low on exactly how much warming we will see going into next weekend. At this time, we expect to be back up to near or a little above normal by Saturday. && .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...JR AVIATION.....JR SHORT TERM...SP LONG TERM....SP