FXUS65 KBOI 020349 AFDBOI Area Forecast Discussion National Weather Service Boise ID 849 PM MST Sun Feb 1 2026 .DISCUSSION...A weak cold front will move just to our east on Monday with slightly cooler temperatures aloft Monday morning. Clearing expected tonight with good radiational cooling. Fog will have a better chance at forming tonight in the lower Treasure Valley with the clearing. Upper level ridge strengthens on Monday and Tuesday and moves overhead by Thursday. Current forecast reflects this with no updates planned. && .AVIATION...VFR overnight with some mid to high clouds, and continued VFR Monday. Areas of MVFR/IFR possible in the Lower Treasure Valley of Oregon and Idaho 04-17Z. Surface winds: variable less than 8 kt, favoring WNW by Monday afternoon. Winds aloft at 10kft MSL: SW 15-30 kt. KBOI...VFR with some mid and high clouds. Surface winds variable less than 5 kt, leaning NW after 17Z Monday. && .PREV DISCUSSION... SHORT TERM...Tonight through Tuesday night...A band of mid/high clouds due to a weak Pacific cold front aloft was passing through our CWA this afternoon. Clouds will decrease from west to east this evening. Higher elevations will cool a few degrees tonight and Monday as the associated upper trough flattens the persistent main ridge. Lower elevations will not be affected. The ridge will re-amplify Tuesday and higher elevations will get warmer again. The warming will intensify the inversion in the valleys below, with the usual patchy fog and low clouds in the night and morning hours. Light winds through Tuesday night. No pcpn. LONG TERM...Wednesday through Sunday...Amplified high pressure along the California coast will become a closed system as it slowly steers eastward through the end of the week. Dry and stagnant conditions will be expected Wednesday through early Friday. Fog/low stratus and colder temperatures will likely return for the basins. A dry and weak shortwave trough will likely move through the area Friday through Saturday, possibly breaking the inversion. Latest long-term guidance now projects a longwave trough digging into the region Sunday, likely bringing precipitation. For now, most precipitation will be rain across except at highest elevations, which may see snow. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Air Stagnation Advisory until 11 AM MST Friday IDZ012-033. OR...Air Stagnation Advisory until 11 AM MST /10 AM PST/ Friday ORZ064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...KA AVIATION.....MC SHORT TERM...LC LONG TERM....JY