PROJECT ALERT NOTICE (WA) Minor flooding in Western WA

Date: Thu, 28 Oct 2021 15:17:49 EDT

Summary: Ongoing precipitation resulting in flooding on the Olympic Peninsula and in Northwest Washington.

An atmospheric river is expected to bring widespread
moderate to heavy rain to Western Washington today and persisting through Friday morning per the Seattle/Tacoma NWS. The current QPF forecast calls for 3-4 inches on the Olympic Peninsula, 4-6 in the Central to Northern Cascades, and a widespread 1-3 in lower areas of Western Washington. USGS precipitation gauges have already recorded 10+ inches in the last 5 days at some locations in the Olympics. Flooding has been occurring in the Skokomish Basin this week, with forecasted rain likely to result in minor flooding in the Skykomish, Stillaguamish, Skagit (potentially moderate flooding), and Nooksack basins in Northwest WA.

Crews from the Western Washington Field Office in Tacoma have been out all week measuring high flow. Additional crews from the Northwest Field Office in Ferndale will be out today and tomorrow measuring expected minor to moderate flooding. A total of 9 staff are deployed in the field today. No peaks of record likely though crews have made some of the highest flow measurements in recent years at select sites. One rating extension has been completed. No reports of malfunctioning gages.

Fieldwork will continue for the remainder of the week. The need for weekend work will be evaluated tomorrow.