A winter storm watch is in effect beginning Saturday morning and continuing until Monday in Upstate South Carolina.

A massive winter storm was set to drop a hazardous mix of freezing rain and heavy snow on some 160 million Americans starting Friday, threatening "catastrophic" icy conditions. State officials there vowed the power grid that failed during a deadly winter storm five years ago and left millions without power was prepared this time around.

The storm will be so extensive, its snow, sleet and freezing rain could stretch more than 1,500 miles from the Plains across the South and into the Northeast. Major travel disruption is a given across its entire footprint.

A major winter storm — among the most extreme and widespread in years — is set to lash more than two dozen states with damaging ice and heavy snow late this week.

VALLEY FORGE, Pa. — Operators of the nation's largest power grid are warning residents in 13 states that electricity demand driven by the coming winter storm will be historically high, placing high stress on the grid and increasing the risk of outages across large parts of the country.

A strong winter storm is expected to impact many parts of central and eastern New Mexico on Friday and Saturday.