Yet another atmospheric river is set to hit Western Washington late Tuesday into Wednesday, bringing more rain into an already soggy Lewis County.
Snow levels up past 8,100 feet will start to thaw during the event as temperatures warm, with the combination of excess rainfall and snowmelt possible leading to river and lowland flooding with an increased risk of landslides, according to Lewis County Emergency Management.
The heaviest rains over the weekend were in the Olympic Peninsula through the North Cascades, according to the National Weather Service.
Winds are forecast to pick up along the coast and north interior late Monday night into Tuesday, but are not expected to be strong enough for considerable impacts.
The Chehalis River Basin Flood Warning System issued warnings on Sunday that the Chehalis River was approaching flood stages near Grand Mound and Montesano. Monday’s river forecasts showed the Chehalis river cresting at 140.85 feet — about 2 inches below the “minor flooding” stage — at Grand Mound on Sunday and beginning to decline on Monday, falling below the action state on Tuesday.
The highest stage at Chehalis River at Grand Mound between 2014-18 was approximately 142.8 feet, according to the Chehalis River Basin Flood Authority.
The Chehalis River rose over the weekend at other river gauges in Lewis and South Thurston counties, but did not approach flood stages.
“Currently, our rivers are tracking to reach the ‘near flood stage’, though this could change depending on how long the rain lasts/where this atmospheric river decides to land,” Lewis County Emergency Management stated in a Facebook post Friday afternoon. “We are watching rivers closely at this time and will keep you updated with any changes.”
The National Weather service warned Sunday that Western Washington residents should “Expect changes in the river forecasts due to high uncertainty in location and timing of heavier rainfall next week.”
For information on current forecasts or to register for email alerts from the Chehalis River Basin Flood Warning System, visit https://chehalis.onerain.com/.
Updated weather forecasts are available online at https://www.weather.gov/.
Updates from Lewis County Emergency Management will be posted to Facebook at https://www.facebook.com/profile.php?id=100072464765616.
