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10h ago

Pacific Northwest Braces for Major Atmospheric River as Flood Watches Expand

Forecasters expect prolonged heavy rain from Monday through Wednesday that will push multiple western Washington rivers toward major flood stage.

Highway digital billboard during snow storm in the Sierra Nevada mountains that reads, "Unsettled Weather Expected, Carry Chains." Oncoming headlights from cars visible.
A map from the National Weather Service (NWS) shows areas at risk of flooding as an atmospheric river takes aim at the West Coast on December 6, 2025.
Satellite image of the first atmospheric river moving over the US West coast on December 5, 2025. Credit NOAA GOES-19, Zoom Earth, The Watchers
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Overview

  • The National Weather Service issued Flood Watches across western Washington and northwest Oregon through late week, with new Flood Warnings posted for the Wilson River, Johnson Creek and the Grays River.
  • Ensemble guidance from CW3E, GEFS and ECMWF shows AR4 to AR5 intensity is possible in parts of Washington, with moisture transport likely to persist for more than 72 hours.
  • Rainfall totals of 3 to 7 inches are forecast broadly, with 10 inches or more along the Olympic Peninsula, coastal ranges and windward Cascades as freezing levels rise during the main event.
  • Local river forecasts indicate the Snoqualmie near Carnation and the Snohomish near Monroe are likely to reach major flood stage, with many rivers cresting Wednesday and Thursday.
  • King tides are prompting coastal flood advisories for minor inundation this weekend, and saturated soils are raising the risk of landslides and urban flooding as the storm intensifies.