Water Resources of the United States
Date: Mon, 15 Nov 2021 10:29:59 EST
Summary: Atmospheric river event in progress resulting in Peak Of Record (POR) and major flood stage for some basins in Northwest Washington.
A second atmospheric river in the last five days is bringing continued heavy rain to Northwest Washington starting yesterday and persisting today per Seattle/Tacoma NWS. A widespread 2-4 (a few 6+ reports) inches have occurred in the last 24 hours with some USGS precipitation gauges indicating 11+ inches over the previous five days. The snow line has risen in the Cascades, with rain on snow increasing runoff. Streamflow exceeded the rating at 9 locations. POR is forecast at 1 location in the Nooksack Basin. Major flood stage is occurring at 3 more streamgages located in the Nooksack, Snohomish, and Skagit Basins Moderate flood stage is forecasted at 7 locations, with 4 more to reach minor flood stage. Forecast hydrographs from the Northwest River Forecast Center are available at the link below.
Crews from the Northwest (Ferndale, WA) and Western Washington (Tacoma, WA) Field Offices were in the field this weekend and will be fully deployed again today. A total of 19 people (11 crews) are in the field, with some staff from the Tacoma Office headed north to support the Northwest Field Office. At least nine sites above the rating, one POR at a forecast site, two flood-damaged gages reported this morning, indirects likely needed at other locations. Road overflow and high winds are hampering access to some areas. No media release planned but some sites on the Skagit or Nooksack River could garner local media attention while USGS crews are present.