A mid-level cold front will slowly sag south across the Inland Northwest today which will lead to breezy westerly winds this afternoon. Weather forecast for today calling for sunny skies and a northwest wind 10-20 mph with possible gusts to 30 mph with afternoon high temperatures still mild into the mid and upper 50’s.
Tonight into Thursday, winds decrease giving way to mostly clear skies into Thursday with slightly cooler temperatures down into the lower 50’s.
The northwest flow aloft flattens out on Friday as a vigorous shortwave weather system develops off the British Columbia coast and carves an upper level trough off the Washington coast with a deepening low-pressure system at the surface. A moist southwest flow will increase east of the Cascades on Friday and interact with cold arctic air dropping down from the Canadian Rockies as precipitation develops and increases throughout the day. Surface winds are forecast to shift to the east and increase by Friday afternoon as the arctic front approaches. Precipitation type will start off as snow in most areas with an 80% chance before 11:00 a.m. then rain is expected during the afternoon with much cooler high temperatures down into the upper 30’s and lower 40’s. With the strengthening of a low-pressure system off the coast and the incoming arctic front, it does not look like anyone in the region is off the hook from a return of winter.
With the inflow of cold arctic air, overnight Friday into early Saturday, we will continue to get more snow into the early Saturday morning hours. Currently, it looks like light to moderate snow addition to Friday, with heavier in the higher elevations. There is a 30% chance of snow for the morning hours with mostly cloudy skies by afternoon with highs only in the mid 30’s. Following the frontal passage, windy conditions are expected to develop across much of the region with sustained winds in the 20-25 mph range with gusts up to 35-40 mph. Some areas of concern include the upper Columbia Basin, Okanogan Valley and Waterville Plateau. With the snowy conditions, winter driving conditions, with blowing snow, is a possibility. Overnight lows Saturday will drop down into the upper teens for most Northcentral Washington locations.
By Sunday, expect a slow warming trend through the week with tempe4ratures on Sunday in the upper 30’s, warming into the lower 40’s by Monday and up top the upper 40’s on Tuesday.