(NEW YORK) -- More than 70 million people in 23 states from California to Connecticut are under flood, heavy snow, blizzard and high wind alerts on Friday as multiple storms move across the country.
By Friday morning, more than 4 inches of rain had already fallen in Northern California, pushing rivers over their banks.
Heavy rain is expected to move into Southern California Friday morning with flooding possible north of Los Angeles in Santa Barbara. Rain will continue in Los Angeles into the evening and will begin to taper off on Saturday.
A flash flood warning was issued for northwestern San Luis Obispo County in southwestern California and will remain in effect until Friday 10 p.m. local time.
Between 2 to 5 inches of rain has fallen in many areas of California, with local amounts upward of 7 inches in the mountains. An additional 4 to 8 inches of rain are possible throughout the day.
There is the potential for especially dangerous flooding by late Friday morning, according to the National Weather Service.
A flash flood warning was in place Friday morning for central Santa Cruz County in Northern California due to heavy rain falling in the San Lorenzo River near Big Trees. The river was rapidly rising and is expected to be in a major flood stage.
But California is not done with rain after this storm. More rain is expected in Northern California over the weekend and into next week.
Heavy snow fell near Redding, California, on Friday shutting down parts of Interstate 5. Some of the heavy snow from the California mountains will move into the Rockies, where a winter storm warning and an avalanche watch have been issued.
Locally, the Rockies could see 1 to 2 feet of snow, with the Sierra Nevada Mountains seeing additional 3 to 4 feet this weekend.
Snow for Midwest and Northeast as well
Part of the western storm will move east over the weekend, bringing blizzard conditions to the Upper Midwest and the Northern Plains.
In the East, a separate storm system is moving from the Great Lakes into the Northeast with heavy, wet snow.
A winter weather advisory is in place in Pennsylvania, New York, New Jersey and Connecticut, where some areas could see several inches of snow overnight. New York City could see up to an inch of snow by Saturday morning.
To the south, severe thunderstorms are possible with damaging winds, few tornadoes and large hail. Oklahoma and Arkansas will be in the bull's-eye on Saturday.
On Sunday, severe weather will impact an area from Mississippi to Georgia, including Jackson; Birmingham, Alabama; and just south of Atlanta. Damaging winds and hail will be the biggest threat.