Northwest flow aloft transitions into a flat ridge of high pressure aloft today into tonight. Northcentral Washington will see temperatures continue to warm with readings well into the upper 80’s to lower 90’s today under sunny skies and a northwest wind 10-15 mph. Winds should start off light, although surface pressure gradients build over the Cascades this afternoon leading to westerly gap winds late this afternoon into the evening as a surface pressure trough migrates into the Columbia Basin.
Breezy westerly winds increase with the frontal passage Thursday and downslope winds in the afternoon and evening hours in the lee of the Cascades, the Waterville Plateau, Okanogan Valley, Wenatchee Valley and into the Columbia Basin. Anticipate sustained winds of around 10-20 mph and gusts 25-30 mph. Thursday temperatures will still be quite warm with highs tomorrow in the lower 90’s.
By Friday, a broad upper level trough of low pressure remains over the Inland Northwest. The weather system won’t affect Northcentral Washington a whole lot with just slightly cooler temperatures with afternoon highs in the upper 80’s.
Confidence is increasing that the Inland Northwest will experience a dry, major warming trend over the weekend and into early next week. An elongated upper-level ridge of high pressure centered over the Eastern Pacific will begin to expand inland allowing the heat dome from the Desert Southwest to make subtle pushes northward into Northcentral and Eastern Washington.
Weather models are pointing to a 1-5 degree warming trend each day from Saturday through Tuesday. Weather forecast for the Columbia Basin and Wenatchee Valley calling for sunny skies each day with afternoon high temperatures in the low to mid 90’s on Saturday and Sunday to the upper 90’s on both Monday and Tuesday, overnight low temperatures will be mild as well with readings around 70 degrees.