Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
810 FXUS65 KBOI 301544 AFDBOI Area Forecast Discussion National Weather Service Boise ID 944 AM MDT Sun Jun 30 2024 .DISCUSSION...A band of light showers was moving east through the Idaho portion of our area this morning. After these showers move east later this morning, we will see some clearing and then isolated thunderstorms this afternoon. The best chance for thunderstorms will be over the West Central and Boise Mountain zones, along with Owyhee and Twin Falls counties. Temps will be about 10 degrees cooler today than yesterday. All this is handled well by the current forecast, and no update is planned at this time. && .AVIATION...Mainly VFR. Mid to high clouds with isolated to scattered showers and thunderstorms today, mainly across the higher terrain of Owyhee County. Isolated showers and thunderstorms will also drift into the Magic Valley late this afternoon and evening, with a 20% chance of a storm at KTWF. Surface winds: W-NW 10-20 kt with local gusts to 30 kt. Gusts to 40 kt near thunderstorms. Winds aloft at 10kft MSL: W-SW 15-25 kt. KBOI...VFR. Mid to high clouds with partial clearing this afternoon. Less than a 10% chance of showers at the terminal. Surface winds NW 10-20 kt with gusts to 25 kt. && .PREV DISCUSSION... SHORT TERM...Today through Tuesday night...At 3 AM MDT a cold front could be clearly seen on satellite imagery extending from northern ID southward along the western ID border, then ssw-ward to near Reno, NV. The surface cold front was slightly east of the main cloud band seen on satellite. KCBX radar showed light rain echoes as far south as central Malheur County but these should retreat northward when they get into Idaho this morning. Surface winds with the front have been stronger than forecast by the models. Around midnight MDT Ontario/OR reported northwest wind 30 mph with gusts near 45 mph. Around 2 AM MDT Boise reported northwest 20 mph with gusts near 30 mph. Behind the cold front high temps today will be about ten degrees cooler than yesterday. Scattered showers and thunderstorms (30 to 60 percent areal coverage) will occur in the central ID mountains, and isolated thunderstorms (15 to 25 percent areal coverage) will develop this afternoon near the NV/ID border. Instability in the central ID mountains looks strong enough for thunderstorm wind gusts up to 50 mph and small hail. Slightly less instability is forecast near the NV/ID border. Clearing and cooler in all areas tonight, with temps holding slightly below normal through Monday as an upper trough passes through from west to east. Mostly sunny Monday, except partly cloudy in the central ID mountains. Breezy again from the west/northwest Monday afternoon. LONG TERM...Wednesday through Sunday...Dry northwest flow will continue Wednesday and Thursday as our area remains between an upper level trough over Montana and a strong upper level ridge centered along the California coast. This will bring dry and breezy conditions with temperatures a couple degrees above normal. Forecast confidence decreases Friday through Sunday as ensembles disagree on the evolution of the pattern. Around 40% of ensembles amplify the ridge along the coast but keep our area under a weak trough, keeping temperatures from becoming too hot. However, the other 60% of ensembles move the ridge inland and bring the potential for very hot temperatures over the weekend. The current forecast is a blend between the two solutions, with lower valleys reaching the upper 90s to around 100 degrees by Saturday and Sunday, but these values are likely to change as models come into better agreement. && .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...SP AVIATION.....JR SHORT TERM...LC LONG TERM....ST