FXUS65 KBOI 270828 AFDBOI Area Forecast Discussion National Weather Service Boise ID 228 AM MDT Mon Oct 27 2025 .SHORT TERM...Today through Wednesday night...Rain and snow showers in ID early this morning will be the last pcpn for several days, except for possible flurries in northern-most mountains Wednesday morning. The main upper trough will exit east this morning as an upper ridge comes in from the Pacific. A faster-moving upper trough from the Gulf of Alaska will race inland along the Canadian border Wednesday while the slower- moving upper ridge stays over our CWA. The trough is the reason for the possible flurries far north Wednesday. West winds will increase to 15 to 25 mph with gusts to 30 mph in south-central Idaho behind today's departing upper trough, but will decrease tonight in all areas as skies clear. Strong radiational cooling will then take place and Tuesday morning will be the coldest of the season so far. Patchy fog will develop in the valleys overnight and last into mid-morning Tuesday as a mild inversion sets up. The incoming upper ridge will allow daytime high temps to warm faster in the mountains than in the valleys starting Tuesday, and patchy valley fog may be slow to clear after the cold nights and low sun angle of late October. .LONG TERM...Thursday through Monday...The long term will start out dry with our area under near zonal flow, resulting from a deepening Alaskan low and high pressure over SoCal. Throughout the day Friday, a moist plume of Pacific moisture will begin to advect over our area ahead of an upper level shortwave and surface cold front associated with the aforementioned low. High clouds will increase across our area Friday as a result of this moisture advection. While the bulk of the moisture is looking to remain to our north, there will be enough residual moisture to support precipitation in our area. Ensemble mean PWATs are progged to reach the around the 90th percentile. This will support elevated precipitation chances north of a line from (roughly) Fairfield/ID to Wagontire/OR. Precipitation chances will range from 20% to 50%, increasing as you move north from that line. The weekend will also be breezy as the pressure gradient tightens. Our area will begin to dry out through Sunday as weak ridging begins to build in again. Temperatures will be seasonable for this time of year, although will lean above normal over the coming weekend. Also, with our area on the periphery of ridging some uncertainty is introduced regarding late week temperatures. && .AVIATION...Precipitation continuing to move east across SW-Idaho, resulting in low VFR/MVFR in rain, IFR/LIFR in snow. Localized IFR at KTWF/KJER early this morning. Generally improving conditions this through the morning. Localized fog this morning in E-Oregon and sheltered mountain valleys in SW-Idaho. Mountains obscured. Snow Levels: Lowering to 2500-3500 ft MSL early this morning. Surface winds: Becoming W-NW 5-12 kt behind the front with gusts to 15-25 kt this morning. Winds aloft at 10kft MSL: W-NW 20-35 kt. KBOI...Rain ended and low ceilings continuing to improve to VFR early this morning. Foothills obscured. Surface winds: W-NW 5-10 with gusts to 20 kt between 09z and 12z this morning. && .PRELIMINARY POINT TEMPS/POPS... Baker City 47 21 51 24 / 10 0 0 0 Boise 49 32 55 34 / 0 0 0 0 Burns 47 16 53 21 / 0 0 0 0 Caldwell 52 29 56 32 / 0 0 0 0 Fairfield 40 12 46 17 / 0 0 0 0 Idaho City 44 17 53 21 / 10 0 0 0 Jerome 41 26 48 31 / 10 0 0 0 McCall 36 16 44 21 / 20 0 0 0 Mountain Home 49 27 54 30 / 0 0 0 0 Ontario 54 27 56 28 / 0 0 0 0 Rome 48 21 57 25 /0 0 0 0 Twin Falls 42 27 48 29 / 10 0 0 0 && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...LC LONG TERM....NF AVIATION.....NF