An area of low pressure is slowly migrating across the Pacific Northwest this morning delivering another day of showers, thunderstorms, and cool temperatures. This morning`s satellite reveals the low center over Astoria, Oregon and slowly drifting to the east/southeast. Ahead of the low center, there is a pronounced circulation or satellite wave moving northward between Royal City and Ellensburg. This feature is expected to drift north then west into the Cascades throughout the day. This will help focus a bulk of the showers and storms over Central Washington today, especially west and north of a line from Quincy to Colville. Localized heavy rain and lightning will remain the main weather concern with this activity and a flash flood watch has been posted for much of the Wenatchee Valley until 8:00 p.m. tonight. Burn scars and steep terrain will remain the most susceptible to localized flooding or debris flows. Expect Northcentral Washington temperatures today to top off around 70 degrees.
On Wednesday, the upper-level low will track east into Wyoming and high pressure will begin to build into the region. In general, this will equate to a warming and drying weather trend region-wide with mostly sunny skies tomorrow with afternoon highs in the upper 70’s.
Thursday, the weather forecast continues to be dry as Eastern Washington is under the influence of a shortwave ridge of high pressure. Look for mostly sunny skies with afternoon temperatures to rebound into the mid-70s with a few low 80s in parts of Northcentral Washington.
On Friday, weather models continue to trend dry weather conditions with a cold front poised to move through the state. For the Columbia Basin, Waterville Plateau and the Wenatchee Valley, Friday`s cold front will produce afternoon winds of 15 mph with gusts to 25 mph. High temperatures Friday in the upper 70’s.
Saturday through Monday, the medium range weather models have come into decent agreement with the timing and track of a large trough developing over the weekend. At this time, it looks like the majority of significant rains on Saturday will remain over Northwest Washington in the vicinity of a slow moving frontal system. The Wenatchee Valley can expect a 30% chance of late-day showers on Saturday with highs in the mid to upper 70’s. Wet and cooler weather for Sunday and Monday with a 30% chance of showers and afternoon high temperatures around 70 degrees.