Cowlitz County creeks could flood Wednesday, rivers Thursday and Friday, meteorologists say

The National Weather Service issued a flood watch from Thursday through Friday in Southwest Washington and Northwest Oregon due to anticipated rain and snowmelt. Minor flooding in low-lying and poorly drained areas, including Cowlitz County, could also start Wednesday, reports the organization.

Portland office Meteorologist Clinton Rockey said rivers that drain into the Oregon Cascades — like the Cowlitz and Lewis rivers — are less likely to flood than bodies of water that drain into the Coast Range — like the Wilson River — or the Willapa Hills — like the Grays River. However, the threat of local floods is still present, Rockey said.

“They’re all going to see strong rises,” he said about area rivers. “The Cowlitz could get into flood stage.”

Unwanted guest

The National Weather Service forecasts the Cowlitz River at Castle Rock will reach just below what the organization calls “minor” flood stage at about 48 feet between Thursday night and Friday morning. Meteorologists predict the Cowlitz River at Kelso is expected to hit minor flood stage at around 21.5 feet around Friday morning.

Rockey said rivers reach flood level when they have surpassed their banks. He said small creeks and gullies could produce minor flooding Wednesday as well.

Rockey said the predicted front is not as strong as an atmospheric river — regions in the sky that transport large amounts of water vapor from the tropics — but the front is “wrapped in moisture” and expected to overstay its welcome.

“Like a rotten family member who doesn’t know when to go home,” he said.

The National Weather Service calls for up to an inch of rain Wednesday night in Cowlitz County, and around 2 inches of rain Thursday. In Longview, Kelso and Castle Rock, the high is expected to reach about 50 degrees Thursday, with south winds up to 13 mph, and gusts up to 25 mph. The high is forecasted to be around 48 degrees Friday with up to another quarter inch of rain.

The National Weather Service reports most flood deaths occur in vehicles and advises people not to drive through water, especially at night when it’s hard to see.