A powerful storm system moving down the British Columbia coast will sweep into the region tonight, bringing heavy mountain snow, gusty winds, and a sharp drop in temperatures that will lead to a widespread hard freeze by Thursday night.
Check out Scott Dorval's video forecast of more rain, storms & snow
Precipitation will begin in southeast Oregon late this evening before spreading into southwest Idaho overnight. Snow levels will initially hover between 5,000 and 6,500 feet, bringing a mix of rain and snow to mountain valleys. Above 6,500 feet, heavy, wet snow will accumulate rapidly, with 10 to 20 inches expected and localized amounts reaching up to two feet through Wednesday evening.
Lower elevations will see periods of rain on Wednesday. By late morning, strong winds will mix down to the surface, bringing 40 to 45 mph gusts to southern Harney, Malheur, and Owyhee counties. A cold front will push through Wednesday evening, bringing a chance of thunderstorms and spreading strong wind gusts into the Snake Plain and Weiser Basin.
Behind the cold front, snow levels will crash to valley floors as precipitation scatters out. Thursday will remain cold and unstable as the upper-level low passes directly overhead, triggering rain, snow, and graupel showers, along with isolated mountain thunderstorms capable of producing brief, heavy snow.
As the system exits eastward Thursday night, clearing skies will allow temperatures to plummet. A widespread hard freeze is expected, with many locations dropping to 28 degrees or lower. Subfreezing morning temperatures will persist through Saturday, posing a threat to early spring agriculture and blooming plants.
Friday will remain breezy and chilly before a ridge of high pressure builds in for the weekend. This will bring a welcome warming and drying trend, with temperatures climbing slightly above normal on Saturday and 5 to 10 degrees above normal by Sunday. Another storm system from the Gulf of Alaska is expected to bring renewed precipitation chances by late Sunday into Monday.
Tonight
A slight chance of rain before midnight, then a chance of rain after 2am. Increasing clouds, with a low around 43. Light wind. Chance of precipitation is 50%.
Wednesday
Rain before noon, then showers between noon and 3pm, then showers and possibly a thunderstorm after 3pm. High near 56. Light morning wind then locally gusty breezes late in the day. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday Night
Rain showers before midnight, then a slight chance of rain and snow showers between midnight and 3am, then a slight chance of snow showers after 3am. Some thunder is also possible. Low around 32. NW wind 10-15 mph with gusts to 35 mph in the evening then becoming light late.. Chance of precipitation is 90%. New snow accumulation of less than a half inch possible.
Thursday
A chance of snow showers before 3pm, then a chance of rain showers. Partly sunny, with a high near 47. West northwest wind 6 to 13 mph, with gusts as high as 25 mph. Chance of precipitation is 40%. Little or no snow accumulation expected.
Thursday Night
Mostly clear, with a low around 28. NW wind 6-12 mph becoming light north northwest after midnight. Winds could gust as high as 24 mph.
Friday
Sunny with cold, frosty morning and cool afternoon, with a high near 54.
Friday Night
Mostly clear, with a low around 32.
Saturday
Mostly sunny with milder afternoon, with a high near 64.
Saturday Night
Partly cloudy, with a low around 42.
Sunday
Partly sunny & pleasant, with a high near 72.
Sunday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 46.
Monday
A 30 percent chance of showers. Partly sunny, with a high near 70.
Monday Night
A 20 percent chance of showers. Mostly cloudy, with a low around 43.
Tuesday
A 30 percent chance of showers. Partly sunny, with a high near 63.
