A closed low off the Oregon coast will send a strong mid-level weather wave through the area late this afternoon into this evening. The Wenatchee Valley and most of Northcentral Washington can expect increasing clouds throughout the morning with a 60% chance of showers and thunderstorms developing by this afternoon with high temperatures in the upper 70’s. Some thunderstorms could contain strong winds, small hail and frequent lightning as well as heavy downpours of rain.
On Thursday and into Friday, all latest weather models are in good agreement in lingering the upper weather system over Western Washington through at least Friday before slowly weakening it into an open trough or weak closed low this weekend and into next week without moving very much. It is rather amazing for this time of year to have such a persistent weather feature sitting smack-dab over Northcentral Washington for such a long period. With that being said, the Thursday and Friday time frame will feature continued cooler than normal temperatures with enough instability to warrant a 50% chance of showers and possibly thunderstorms on Thursday and a 40% chance of Friday with afternoon highs both days in the lower 70’s.
The weekend will feature dry weather conditions with a warming trend back to near normal for this time of year on Saturday with highs in the upper 70’s to near 80 degrees in the Wenatchee Valley and above normal temperatures into the lower and mid 80’s on Sunday. For next week, weather models are indicating a building ridge of high pressure with sunny skies both Monday and Tuesday and afternoon high temperatures in the mid to upper 80’s.