780 FXUS65 KBOI 261527 AFDBOI Area Forecast Discussion National Weather Service Boise ID 927 AM MDT Sat Oct 26 2019 .DISCUSSION...West winds are already near advisory levels in the western Magic Valley. Latest guidance continues gusty winds through the day. Will issue a wind advisory through 7 PM MDT for the western Magic Valley, southern Twin Falls County, Upper Treasure Valley east of Boise, and the southwest Idaho Highlands (northern part of Owyhee County). These winds are behind a dry cold front that passed through the area early this morning, so temperatures will also be much cooler than yesterday. Snow showers are possible in eastern-most Idaho zones today, continuing tonight in south-central Idaho. Record low temps are possible Monday morning (although winds will be only light and variable). Even colder wx is possible Wednesday as the core of an arctic air mass comes south from interior northwest Canada into western Montana and Wyoming. Halloween looks a little warmer but still quite cold. && .AVIATION...VFR with scattered to broken mid-level clouds. Isolated to scattered snow showers in the West Central Mountains causing mountain obscuration and MVFR/IFR conditions through 27/00z. MVFR/IFR south of KJER thru Jackpot, NV with scattered snow showers and mtn obscuration 27/00z thru 27/09z then improving. Surface winds: generally NW 15 to 25 kts with gusts up to 35 kts east of KMUO. Winds shift to North after 27/00z. Winds aloft at 10K ft MSL: West to Northwest 20 to 40 kts, shifting North to Northeast 15 to 30 kts aft 27/00z. && .PREV DISCUSSION... SHORT TERM...Today through Tuesday...Much cooler today behind the overnight cold frontal passage. High temperatures will be 15-25 degrees cooler than yesterday, with gusty winds adding a chill. The strongest winds will be along the I84 corridor from Baker City to Twin Falls where gusts to 40 mph are possible, especially in Baker county and the Snake Plain east of Boise. Snow showers will develop across northern Valley county by late morning in association with an upper trough dropping into central Idaho. Development will shift southward through the afternoon. An area of surface convergence coupled with the instability and lift along the advancing trough will support a period of light rain/snow over portions of the Snake Plain east of Glenns Ferry this evening. Temperatures will likely be too warm for much snow accumulation, but a coating is possible. Dry and cold conditions follow for Sunday and Monday under northerly flow aloft. A second shortwave trough will drop along the Divide on Monday, reinforcing the cold air mass and bringing another chance of light precipitation to the w-central Idaho mountains and middle Snake Plain Monday night. Tuesday will be dry and cold as northerly flow remains in place. High temperatures will average around 15 degrees below normal for Sun-Tue with record low temperatures possible Monday morning. LONG TERM...Tuesday night through Friday...Northeast flow aloft will continue through Wednesday as cold, dry conditions persist into the extended. A deep trough will continue to stretch over the Intermountain West, lowering temperatures roughly 10-15 degrees below the seasonal average. After this system cycles eastward, northwest flow aloft over the region will limit warming to a degree or two each day through Saturday. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Wind Advisory until 7 PM MDT this evening IDZ014>016-030. OR...None. && $$ www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise DISCUSSION...LC AVIATION.....CR PREV SHORT TERM...DG PREV LONG TERM....AL