Winter weather moves east after ice storm hits from Oklahoma to Illinois

After a day of historic rainfall in California, parts of the South are on alert for flooding and states in the north are preparing for ice as winter weather sweeps across the U.S.

In San Diego, where a state of emergency was declared, more than a month's worth of rain fell in three hours on Monday. It was the city's wettest January day on record, with a rainfall total of 2.73 inches. Typically, San Diego gets 1.98 inches of rain for the entire month of January.

Dozens of rescues were reported across San Diego County due to the historic rainfall.

Over the past three days, parts of Northern California and Southern California recorded 5 to 9 inches of rain amid a continuous onslaught of Pacific storms.

Most of California and the West Coast are expected to get a break from stormy weather, but more rain and snow is in the forecast for Northern California on Wednesday.

Part of the western storm that hit California is expected to combine with moisture in the Gulf of Mexico to bring rounds of heavy rain to the South this week.

Rain and potential thunderstorms will hit Tuesday night through Thursday from Texas to Missouri to Georgia.

The highest threat for flooding will be from Houston to Little Rock, Arkansas, to Huntsville, Alabama, where more than 6 inches of rain is possible.

Meanwhile, an ice storm that struck states from Oklahoma to Illinois on Monday, leaving more than a quarter of an inch of ice on roads, sidewalks and trees, is moving into the Great Lakes region and parts of the Northeast on Tuesday.

A glaze of ice and 1 to 2 inches of snow is possible from Kansas to Massachusetts.

Schools closed in Cedar Rapids, Iowa, on Tuesday due to the weather.

The Northeast is expected to see an icy mix on Tuesday, with snow for Pennsylvania, upstate New York and the Hudson Valley, northern New Jersey, Connecticut and Massachusetts. There could be slick roads by the evening commute in parts of the Northeast.

Meanwhile, a major thaw is on the way for millions of Americans. Temperatures are expected to surpass 40, 50 or even 60 degrees in parts of the Midwest and Northeast later this week.