398 FXUS65 KBOI 192030 AFDBOI Area Forecast Discussion National Weather Service Boise ID 230 PM MDT Thu Oct 19 2017 .SHORT TERM...Tonight through Saturday...Satellite data continues to show increasing cloud cover across the Pacific Northwest this afternoon, with observations noting hints of the cold front moving off the Pacific coastline. Gusty winds noted across Oregon and portions of central Idaho this afternoon ahead of this anticipated front. Models continue to indicate this front arriving into eastern Oregon late tonight and moving into southwest Idaho early Friday morning. As the front progresses, expect the threat for gusty wind to continue, with precipitation expected to accompany the front. Snow levels will decrease to around 6k ft tonight, leaving mountain snowfall possible. Temperatures on Friday are expected to be between 10 and 20 degrees cooler than today. Shower activity will weaken through the evening hours as the front moves east of the area. However, another push of moisture will move into eastern Oregon late Friday night, spreading across Idaho on Saturday afternoon and evening. This will continue to wet and cool pattern, with temperatures remaining generally 5 to 10 degrees below normal. .LONG TERM...Saturday night through Thursday...Moist westerly flow aloft will continue to support showers, mainly over the mountains of Baker County Oregon and west central Idaho, through Sunday night. An upper level ridge building over the west coast will cut off the moisture supply on Monday. Tuesday night an upper level trough from the Gulf of Alaska will weaken as it moves into British Columbia and encounters the ridge. The trough will slide southeast across northern Idaho and western Montana Wednesday afternoon and evening as the ridge rebuilds offshore. Precipitation with this system is expected to stay north and east of our area, and there will be little effect on temperatures, which will continue near or slightly above normal. && .AVIATION...VFR through this evening. Increasing and lowering clouds tonight ahead of a Pacific cold front, currently timed to pass KBKE and KBNO about 09z, KMYL and KBOI about 12z, and KTWF and KJER about 15z Friday. Expect deteriorating conditions after 06z, with showers spreading across the area, and areas of mountain obscuration and MVFR ceilings. Snow levels lowering from 7000-8000 feet MSL tonight to 5000-6000 feet MSL Friday morning and around 5000 feet MSL Friday afternoon. Surface winds mainly east to southwest 10-20 kts, shifting to west 10-20 kts following the front. Winds aloft at 10kft MSL southwest 30-40 kts. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise SHORT TERM...KB LONG TERM....JT/JT AVIATION.....JT |