Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
782 FXUS65 KBOI 171555 AFDBOI Area Forecast Discussion National Weather Service Boise ID 955 AM MDT Mon Jun 17 2024 .DISCUSSION...Showers associated with an unseasonably cool upper low will continue today. Marginal instability will also support a slight chance (less than 20 percent) of afternoon thunderstorms, accompanied by gusty winds and small hail/graupel. Snow levels remain near 5000 feet with light snow accumulations in the mountains. Gusty winds increase through the afternoon, especially in the Western Magic Valley where a Wind Advisory is in effect. No updates. && .AVIATION...Scattered to numerous rain and snow showers will continue through the afternoon before tapering off this evening. Isolated thunderstorms will also develop today. VFR/MVFR ceilings this morning, with local areas of IFR and obscuration in mountains. Snow levels 4500-6000 ft MSL. Patchy mountain valley fog developing overnight. Surface winds: W-NW 10-20 kt with gusts 20-30 kt, except gusts 30-40 kt near the Magic Valley terminals. Winds aloft at 10kft MSL: W-NW 20-35 kt. KBOI...30-50% chance of showers and temporary MVFR ceilings at the terminal thru 00Z/Tue, with the highest chance late this morning. Showers have around a 10% chance of developing into thunderstorms this afternoon in the vicinity of the terminal. Surface winds: NW 10-20 kt with gusts 20-30 kt. && .PREV DISCUSSION... SHORT TERM...Today through Wednesday night...A unseasonably cool upper level trough will move over the area today, bringing rain and mountain snow above 5000 feet. Minor accumulations of generally 1-2 inches over the mountains today, with locally higher amounts on the mountain peaks. Precipitation will continue this morning, before becoming showery in nature this afternoon. As the cold air aloft moves over the area, instability will help fuel showers and thunderstorms this afternoon, some containing small hail and graupel. Breezy west to northwest winds this afternoon, generally 20-30 mph, with gusts to 45 mph possible in Magic Valley, where a wind advisory is in effect from noon to 7pm today. Winds should subside by Tuesday morning. Monday night into Tuesday morning will be the coldest night of the forecast period with temperatures in the 20s in the mountain valleys, while the Snake Basin will be 35-40 with patchy frost. The system will exit on Tuesday with lingering showers over the central ID mountains. A drying and warming trend starts with about 10 degrees of warming on Tuesday and another 10 degrees on Wednesday. LONG TERM...Thursday through Monday...Southwest flow aloft develops midweek and lasts into this weekend, supporting a gradual warming trend each day. Valley highs are favored to reach the lower 90s in the valleys by Friday and mid-upper 90s Saturday and Sunday. Winds in the long term remain mostly mild, but breezy winds are possible Sunday and next Monday. There is not enough moisture in the flow to warrant any convection, although even limited moisture could yield afternoon convection as the heat builds. Our current forecast remains dry through the period. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory until 7 PM MDT this evening IDZ016. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...BW AVIATION.....ST SHORT TERM...KA LONG TERM....JM