PROJECT ALERT NOTICE (WA) Major Flooding in Western Washington

Date: Fri, 12 Nov 2021 09:54:26 EST

Summary: Atmospheric river event in progress resulting in forecasts of major flood stage today for some basins in Western Washington.

An atmospheric river brought moderate to heavy rain to Western Washington starting yesterday and persisting into today per Seattle/Tacoma NWS. A widespread 3-5 inches has occurred with locally higher amounts recorded at USGS precipitation gauges. Major flood stage is expected at 6 streamgages located in the Nisqually, Cowlitz, Puyallup, and Skagit Basins today per the Northwest River Forecast Center. Moderate flood stage is expected at 6 locations, with 9 more to reach minor flood stage. Forecast hydrographs are available at https://www.nwrfc.noaa.gov/rfc/hydrographs/. A second atmospheric river is expected late Saturday, lingering into Sunday, with secondary river peaks likely.

Crews from the Northwest (Ferndale, WA) and Western Washington (Tacoma, WA) Field Offices are in the field today and again tomorrow. A total of 18 people (9 crews) are deployed. No peaks of record forecasted, but multiple sites have already reached flows above the highest recorded non-poor discharge measurement on record. No reports of malfunctioning gages this morning.