A weather system known as an "atmospheric river" is unleashing heavy rain across California, bringing the threat of mudslides and flooding Thursday to a region that's already been slammed by days of rain and heavy snow. The National Weather Service's Weather Prediction Center said a strong storm system is unleashing an "anomalous surge of tropical moisture" across the Golden State. "There is a high risk of excessive rainfall on Thursday for the southern California mountains, capable of causing flash flooding and mudslides." The storm system is part of what's known as an atmospheric river, which the National Oceanic and Atmospheric Administration says is a huge plume of subtropical moisture. "These columns of vapor move with the weather, carrying an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi River."

Source: Fox News February 14, 2019 18:56 UTC