Wednesday, December 15, 2021
A series of atmospheric rivers pushed Washington's Skokomish River into moderate flooding on November 10, with more rounds of heavy rain and wind forecast through November 14.
A series of atmospheric rivers is soaking the Pacific Northwest this week, and the first river is already out of its banks. The National Weather Service in Seattle issued a flood warning Tuesday night for the Skokomish River at Potlatch in Mason County, Washington. The river stood at 17.4 feet at 9:30 p.m. Tuesday and was forecast to crest near 17.5 feet overnight. At that level the NWS expects moderate flooding. Deep, fast water can cover some homes, many roads and much of the farmland in the Skokomish Valley. Skokomish Valley Road, Purdy Cutoff Road and Highway 106 are among the routes named in the warning.
The Skokomish should fall below flood stage around midday Wednesday, but the NWS says it could return to flood stage late this week. The storms are arriving in rounds through Saturday, November 14. AccuWeather forecasters say parts of western Washington and coastal British Columbia could see more than 12 inches of rain over that stretch, with the heaviest totals on west and south facing mountain slopes. NOAA's Climate Prediction Center gives parts of the Pacific Northwest and northern California a moderate risk of heavy rain and possible flooding from November 11 to 15. Coastal gusts up to 50 mph and seas near 20 feet add the risk of downed lines and power outages. Every total here is a forecast as of Wednesday morning and is likely to change as the week goes on.
The rounds are what make this setup dangerous. Each storm lands on ground still soaked from the last one, so small streams and rivers rise faster with every pass. Leaves clog storm drains and push water into streets, and slopes burned in this summer's fires can let loose mudslides and debris flows. Western Oregon and northern California sit in the path of the later storms, so the flood risk moves south as the week goes on. Solid flood preparedness starts before the water rises, while roads are still open and stores are still stocked.
If you live in a river valley or a low coastal area, pack a flood emergency kit in waterproof containers and keep it near the door. Walk through your family flood plan tonight so everyone knows the route to higher ground and where to meet. Homes with a history of water at the door can set sandbags for flooding now, ahead of the next round. Wind is the other half of the storm, so charge phones and lights and check your power outage kit before the gusts arrive. Turn around at any flooded road. A foot of moving water can float a car.
As of Wednesday morning the strongest storm in the series was aimed at Vancouver Island, with more rain and mountain snow due for Washington, western Oregon and northern California from Thursday through Saturday. Sign up for your county emergency alerts and check the NWS forecast for your area today.
