Cool and quiet weather will persist across Northcentral Washington today under a dry northerly flow aloft. But, as the day progresses, an arctic front currently over Western Canada will drop southward across the region this afternoon and tonight. Expect mostly sunny skies today with afternoon high temperatures in the lower to mid-50’s.
By tonight, winds will develop along the cold front beginning in the Okanogan Valley and then moving through the Columbia Basin later in the afternoon and evening. Local wind gusts of 40-50 mph will be possible, especially in channeled terrain. Wind advisories will be issued for the strongest wind locations, including the Okanogan Valley and Purcell Trench. It is rather unusual for gusty north to northeast winds of this magnitude this time of year, and enhanced impacts will be possible due to this fact. These winds will also usher in some of the coldest temperatures of the season thus far. The temperature forecast for tonight will be a bit tricky and will be highly dependent on how quickly winds drop off. Locations that do decouple will have the potential to drop into the teens, locally even single digits. Locations that remain better mixed may see lows in the 20s to 30s. The Wenatchee Valley will see mostly clear skies tonight with lows in the lower 20’s.
The cold air sticks around on Tuesday under mostly sunny skies afternoon high temperatures will only be in the upper 30’s to near 40 degrees.
Beginning on Wednesday, the Inland Northwest will be under a predominantly northwest flow with very quiet weather expected. A shortwave ridge of higher pressure will move across on Wednesday, and then this will be followed be an upper level disturbance for Thursday. Many areas will continue to see very cold temperatures into Wednesday morning with lows bottoming out in the low teens. Northcentral Washington will see sunny skies each day Wednesday through Sunday with afternoon high temperatures only in the lower 40’s on Wednesday, mid to upper 40’s on Thursday, upper 40’s to lower 50’s on Friday and nice weather expected for the weekend with highs then in the mid to upper 50’s.
Air Stagnation will also be a potential concern through the week for people with breathing and health issues.