As Western Washington reels from catastrophic flooding that swept the areas along major river valleys, another plume of moisture will arrive on Sunday, according to the National Weather Service.
An atmospheric river rolled into the region Monday, bringing devastating floods to several areas and hitting communities along the Nooksack, Skagit, Skykomish and Snohomish rivers hard.
Usually, atmospheric rivers aren’t unusual, bringing mild showers and gray skies. This time, Seattle NWS meteorologist Anna Lindeman said unusually warm temperatures caused snow levels to rise so high that most of the moisture fell as rain, rapidly feeding rivers and worsening flooding. Some areas saw more than 12 inches of rain…