Nearly 65 million Americans under weather alerts as winter storm blasts country - with Philadelphia forecasting biggest snowfall in two years and California braced for MORE flooding and mudslides

Nearly 65 million Americans are under weather alerts as a quick-hitting winter storm blasts the country.

Much of the East Coast woke up to a blanket of snow on Saturday morning, with Philadelphia braced for its biggest dump in two years.

The National Weather Service warned that up to an inch an hour could fall in the Pennsylvanian city, with totals hitting up to six inches by lunchtime.

Advisories were also issued for New Jersey and New York, where the snowfall had already passed expectations by up to six inches in some areas.

Drivers were being warned of difficult conditions, while temperatures are expected to hover around freezing when wind chill is factored in.