Area Forecast Discussion
Issued by NWS Boise, ID
Issued by NWS Boise, ID
247 FXUS65 KBOI 250235 AFDBOI Area Forecast Discussion National Weather Service Boise ID 835 PM MDT Mon Jun 24 2024 .DISCUSSION...Mild temperatures under clear skies with light winds tonight. Hotter temperatures will return Tuesday as an upper level ridge builds overhead, accompanied by southwest flow aloft. Lower valleys will reach the upper 90s to near 100 degrees. Mid to upper level moisture will increase from the south late Tuesday bringing increasing clouds. The increasing moisture will lead to a threat of showers and thunderstorms Tuesday night into Wednesday as a shortwave trough approaches. This is all handled by the current forecast and no updates this evening. && .AVIATION...VFR with clear skies tonight. Increasing mid to high clouds from the south Tuesday afternoon. Reduced visibilities from smoke near a fire in far SW Idaho. Hot temperatures on Tuesday will result in high density altitudes. Surface winds: variable 10 kt or less overnight, becoming SW-NW 5-15 kt Tuesday afternoon. Winds aloft at 10kft MSL: W-SW 10-20 kt. KBOI...VFR with clear skies. Increasing high clouds Tuesday afternoon. Surface winds: variable 6 kt or less overnight, becoming NW 5-10 kt Tuesday afternoon. && .PREV DISCUSSION... SHORT TERM...Tonight through Wednesday night...A dry west- southwest flow aloft through Tuesday (accompanied by dry condition) transitions to a moist southwesterly flow Tuesday night through Wednesday. Initially, moisture arrives in the mid and upper levels, but translates to the lower levels on Wednesday as the precipitable water peaks at around 1 inch which is around the 95th percentile. The convective threat increases with the increase in moisture as any thunderstorms would be high-based Tuesday night through early Wednesday, with the potential for heavy rain with the thunderstorms by Wednesday afternoon. Shower/thunderstorm chances will be generally less than 30 percent with the best chances over the higher elevations. Gusty winds develop during the afternoon ahead of an approaching cold front that is associated with a trough over the PacNW. The front moves through Tuesday night, followed by drier/stable conditions into Wednesday. Much-above normal temperatures continue both days with highs around 10 degrees above normal. LONG TERM...Thursday through Monday...Cooler temperatures (near seasonal normals) follow the passage of the midweek cold front Thursday through Friday. Breezy northwest winds are anticipated on Thursday with lighter winds on Friday. Showers chances will be confined to the far north (West Central ID Mountains) on Thursday with dry conditions area-wide on Friday. The cooler northwest flow becomes southwesterly on Saturday bringing a return to above-normal temperatures. Models remain in good agreement with the arrival of the next Pacific trough early next week for a slight cooling trend and a 15-30 percent chance of showers, mainly over the higher elevations. && .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...ST AVIATION.....ST SHORT TERM...BW LONG TERM....BW