A dry westerly weather flow across the Inland Northwest today will bring mostly sunny skies and a light breeze. Temperatures will be slightly cooler compared to Monday and winds a bit weaker. Otherwise, plenty of sunshine and a benign weather day with afternoon high temperatures in the lower 80’s.
On Wednesday, winds will increase a bit more through the Cascade gaps as the next cold front approaches our area off the Eastern Pacific. Cooler air on the west side will make a push through the Cascades and tighten the pressure gradient tomorrow as high and mid-level clouds thicken east of the Cascades by the afternoon and into the evening. For the Wenatchee Valley on Wednesday expect increasing clouds, west winds 5-10 mph with afternoon high temperatures in the mid 70’s.
Thursday through Friday, chances are quite good that this will be the coolest period of the upcoming week as a deep offshore trough shifts inland riding down the front side of our high-pressure ridge. On Thursday, the core of the upper low will move over western Washington with deepest instability either located over the Cascades with another area expected to be just east and south of our forecast area. Expect partly cloudy skies Thursday and much cooler temperatures with highs in the lower 70’s. There will be a better chance of active weather on Friday as the core of the upper level weather system shifts east of the Cascades and leaves the entire forecast area on the cold and unstable side of the upper level jet. We will see partly to mostly cloudy skies on Friday with a chance for a shower or two with high temperatures near 70 degrees. This air mass will be moist, but it should also be significantly cooler with temperatures 15-20 colder than what we saw last weekend. Some of the temperatures in the mountains could struggle to exceed the upper 30s to middle 40s during the daytime hours.
By Saturday, the core of the upper level trough will shift into Western Montana with an upper level ridge of high pressure pushing onto the British Columbia coast. Expect cool temperatures to continue with high temperatures only in the lower 70’s.
On Sunday the trough moves east with ridging poking over the entire Inland Northwest. The Wenatchee Valley will see sunny skies on Sunday and Monday with a warming trend. Afternoon highs will once again rise above the seasonal normals with readings in the 80s on Sunday and Monday and possibly into the lower 90s by Tuesday afternoon in some locations.