After storms covered much of California with snow, more storms this week could lead to the risk of flooding.
The National Weather Service predicts that a tropical storm will hit central California on Thursday, melting the snowpack and leading to possible flooding.
The “impactful atmospheric river” poses a level 3 to 4, or moderate, risk of excessive rainfall “as the threat of several inches of heavy rain into high-terrain favorable regions given increased snow levels as well as the additional impacts of snow melt will increase the risk of flooding,” per NWS.
What is an atmospheric river?
In an atmospheric river, a channel of wind carries heavy tropical moisture that “can be deadly and cause a lot of damage,” Hanna Seariac writes in the Deseret News.
“Atmospheric rivers that contain the largest amounts of water vapor and strongest winds lead to extreme rainfall and flooding, causing damage to property and inducing mudslides,” National Weather Service senior forecaster Bob Oravec told NPR.
What areas of California are under flood watch?
About 16 million people in northern and central California are currently under flood watch before the storm hits Thursday, CNN reported.
A strong storm system will impact Central California Thursday evening through Friday night, resulting in excessive rainfall and possible flooding in most of the area. A Flood Watch is in effect. The majority of this precipitation will fall Thursday night and Friday. #CAwx pic.twitter.com/llceU48dWB— NWS Hanford (@NWSHanford) March 8, 2023
See a list of updated watches, warnings or advisories for California from the National Weather Service here.