A longwave trough is currently over the Pacific Northwest. A shortwave, or weaker disturbance, is now beginning to move inland, sparking up some showers across the viewing area. These showers are going to continue tomorrow, and gradually diminish from west to east as the whole system pushes into the Intermountain West. We will see a break in the rain during the late afternoon and early evening Sunday, before our next disturbance moves in.
This next shortwave will bring heavier rains to the region throughout the holiday. If you have plans to be outdoors, plan for both cold and wet weather. Occasional showers will produce heavy rain at times, especially for the Coastline, Coastal Range Mountains and Umpqua Basin.
Unsettled weather, with unseasonably cool temperatures, is going to persist into midweek. Several more weaker disturbances will bring a chance for rain to most areas into Wednesday evening, and possibly even Thursday. It has been an extremely dry month so far, with the precipitation departure from normal almost three quarters of an inch, so the rain moving in for the upcoming days is certainly needed–especially in the Basin. Unfortunately, it has to be for the holiday weekend when many plan to be outdoors! Again, be prepared for cooler temperatures and also periods of rain.
Have a wonderful Memorial Day, and enjoy the time with family and friends!