Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
518 FXUS65 KBOI 260301 AFDBOI Area Forecast Discussion National Weather Service Boise ID 901 PM MDT Tue Jun 25 2024 .DISCUSSION...The leading edge of moisture arriving from Nevada has crossed into far SE Oregon/SW Idaho this evening. Radar shows isolated high-based showers with the initial surge, but better moisture will move into southern areas overnight accompanied by scattered showers and isolated thunderstorms. The showers/thunderstorms expand in coverage on Wednesday. Afternoon heating will enhance the potential for stronger outflow winds, with some storms capable of producing gusts to around 50 mph. In addition to the convection, winds increase in SE Oregon Wednesday afternoon ahead of an approaching cold front with gusts in excess of 30 mph. No updates. && .AVIATION...VFR. Increasing mid/high level clouds. Scattered showers and thunderstorms developing overnight across SE Oregon and near the ID/NV border. Surface winds: variable less than 10 kt. Winds aloft at 10kft MSL: SW 10-20 kt. KBOI...VFR. Increasing mid-high clouds. Surface winds: variable less than 10 kt becoming southeast after 04Z. && .PREV DISCUSSION... SHORT TERM...Tonight through Thursday night...A shortwave trough will move into the area tonight, bringing a rare nocturnal convective event to the region. Storms are expected to develop after 06Z in SE Oregon, and move into SW Idaho after around 09Z. These storms will be capable of wind gusts 40-50 mph. Storms will continue into Wed afternoon on the Idaho side, and wind gusts could approach 60 mph in the strongest storms. PW values increase tonight, so brief heavy rain is also possible in the strongest storms. As the system departs Wed afternoon, the PW will decrease rapidly. Winds will increase, especially in SE Oregon, Wed afternoon. The combination of lightning and stronger winds has prompted the issuance of a Red Flag Warning for parts of the area from late tonight through Wed evening (see the Red Flag Warning for details). After tonight`s initial shortwave, a larger upper level trough will move through Thursday. This will bring very few additional showers, but much cooler air. After temperatures around 10 degrees above normal tomorrow, readings will be around 5 degrees below normal Thu and again Fri, with Thu being the coolest day. Northwest winds Thursday afternoon and early evening will be gusty (15-25 mph) for most areas, and even stronger in the upper Treasure and western Magic Valleys (25-35 mph). LONG TERM...Friday through Tuesday...We will remain dry Friday until Saturday evening as dry NW flow aloft shifts gradually to SW ahead of a trough developing off the coast. The trough will gradually move inland through Sunday and cross our area Sunday night. As this occurs, a chance of precipitation will return Saturday evening and increase through Sunday afternoon/evening. Thunderstorms are possible, especially in the higher terrain and south of the Snake River. We should dry out Monday and remain dry for Tuesday. Saturday will be the warmest day of the long term, with temps 5-10 degrees above normal. Otherwise, temperatures should be around normal. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Red Flag Warning from 6 AM to 9 PM MDT Wednesday IDZ401-402. OR...Red Flag Warning from 3 AM MDT /2 AM PDT/ to 9 PM MDT /8 PM PDT/ Wednesday ORZ636-637. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...BW AVIATION.....BW SHORT TERM...SP LONG TERM....SP