NoticeHydrologic Outlook from NWS Seattle WA
ESFSEW
Another strong atmospheric river will impact western Washington
starting late Sunday extending into mid week. Snow levels will rise
as high as 8500 feet Monday before lowering to 3500 to 4500 feet
Tuesday. Soils will still be saturated and rivers will be elevated.
A few rivers might not drop below flood stage before this round of
rain begins.
Expect rising rivers with the potential for flooding, urban
flooding, and landslides. Debris flows are also possible throughout
this period.
Please monitor the latest river forecasts from the National Weather
Service for additional information.Flood Watch from NWS Seattle WA
WHAT: Flooding caused by excessive rainfall is possible.
WHERE: Portions of northwest and west central Washington, including the following counties, in northwest Washington, Clallam, Grays Harbor, Jefferson, Kitsap, Mason, Skagit and Whatcom. In west central Washington, King, Lewis, Pierce, Snohomish and Thurston.
WHEN: From Monday morning through Thursday afternoon.
IMPACTS: Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Creeks and streams may rise out of their banks. Flooding may occur in poor drainage and urban areas. Storm drains and ditches may become clogged with debris. Area creeks and streams are running high and could flood with more heavy rain.
ADDITIONAL DETAILS: - A series of weather systems next week will bring another round of significant rainfall to western Washington late Sunday through Wednesday. Preliminary liquid totals of 2 to 8 inches will cause additional sharp rises to area rivers, with many forecast to enter moderate and even major flood stage early next week. Urban and small stream flooding remains possible for areas with poor drainage. Very saturated soils will maintain increased risk for potential landslides and debris flows off of burn scars. - Http://www.weather.gov/safety/flood
Special Weather Statement from NWS Seattle WA
Rainfall of 2 to 12 inches over the past several days, with locally
higher amounts to 17 inches, has increased soil moisture to very
high levels across western Washington. This amount of rain will put
extra pressure on soil instability, leading to an increased threat of
landslides and debris flows, especially from recent burned areas.
Numerous landslides have already been reported in the western
Cascades in western Washington. More landslides are possible.
Areas most susceptible to landslides debris flows under these
conditions are steep coastal bluffs, other steep hillsides or
road cuts, and recent burned areas. A diminishing threat of
landslides and debris flows will continue for several days after
the rain ends.
For more information about current conditions, visit
www.weather.gov/seattle, select Hydrology, and then scroll down
for the links to the landslide information pages.
For more information on landslides, visit the website for the
Washington State Department of Natural Resources landslide
geologic hazards at: http://bit.ly/2mtA3wn 
