Monday, December 7, 2015

Forecasters Heavy Rain Means Landslide Danger and Flooding

Special Weather Statement for Heavy Rain & Landslide Danger
  • Southwest Interior (South Mason County)
  • Hood Canal Area (North Mason County)
  • Western Whatcom County
  • Western Skagit County
  • Everett & Vicinity
  • Tacoma Area
  • Lower Chehalis Valley Area
  • Western Strait of Juan de Fuca
  • North Coast
  • Central Coast
  • East Puget Sound Lowlands
  • Bellevue & Vicinity
  • Seattle & Vicinity
  • Bremerton & Vicinity
Heavy rainfall today through Wednesday will lead to an increased threat of landslides in western Washington State.

Periods of heavy rainfall over the past week have increased soil moisture to moderate levels across western Washington State. Heavy rainfall of 2 to 5 inches across the interior lowlands and 3 to 6 inches along the coast is expected today through Wednesday. This amount of rain will put extra pressure on soil instability, leading to an increased threat of landslides.

Flood Watch in Effect from Tuesday Morning through Wednesday Afternoon

The National Weather Service in Seattle has issued a flood watch for much of Western Washington State, including Mason County.

Excessive rain, especially in the mountains, will probably result in flooding on the more flood prone rivers of western Washington State beginning Tuesday or Tuesday night. Minor to moderate flooding is possible on most of the rivers that flow off the Olympic Mountains and the west slopes of the Cascade Mountains. Most rivers should crest Wednesday or Wednesday night.


A succession of strong fronts will bring around 5 to 11 inches of precipitation to the mountains of western Washington today through Tuesday night. The snow level will rise to 5500 to 6500 feet today and 8000 feet on Tuesday, then start falling late Tuesday night to around 3500 to 4500 feet late Wednesday.