Residents in Lewis County should be prepared for significant incoming rainfall and heavy winds over the weekend and into next week.
Beginning the evening of Saturday, Dec. 2, a Flood Watch issued by the National Weather Service will go into effect for the Chehalis, Newaukum and Cowlitz rivers.
“We are going to see a lot of rain,” said Samantha Borth, a meteorologist with the National Weather Service office in Seattle.
The Flood Watch, which advises residents to “be prepared” as conditions are forecast to be “favorable for flooding,” is set to be in place through Wednesday, Dec. 6. Immediate action is not necessary until a “Flood Warning” is issued.
The Chehalis River at Centralia is forecast to reach the “minor” flood stage between 4 and 10 p.m. on Dec. 5. Downstream, at Grand Mound, the Chehalis River could reach “moderate” flooding on Monday and lasting through Thursday.
Along the Newaukum River in Chehalis, “moderate” flooding is forecast on the evening of Dec. 5.
For the Cowlitz River, Packwood may hit the “action” stage of flooding on Tuesday, while Randle could see “moderate” flooding throughout the day on Tuesday and into the following evening.
Weather service flood stages, from least to most severe, are action, minor, moderate and major.
“That could all still change,” Borth said. “Right now, it looks like the rivers are likely to flood. But the timing and peak could be adjusted. … There is still some uncertainty as to severity.”
All Lewis County residents, regardless of their proximity to a river, should brace for heavy winds.
“The winds are going to increase overnight and peak Saturday morning,” Borth told The Chronicle on Friday. “Wind gusts (are) possible from 35 to 45 miles per hour.”
The National Weather Service website shows forecasts for rivers and weather in general, and Borth said she recommends keeping an eye on the page.
The Chehalis River Basin Flood Authority has an email alert system that sends automatic email alerts about rising water at gauges of the receiver’s choice. To sign up or read other information from the Flood Authority, visit https://chehalis.onerain.com.
To sign up for notifications from the county’s Division of Emergency Management, search online for Lewis County Alerts or visit https://lewiscountywa.gov/departments/emergency-management/lewis-county-alert.
“Make sure you’re paying attention, going into next week, at least,” Borth said. “It’s possible you will see additional headlines.”