Winter storm hits California and Northeast U.S.

A wet winter storm hit Northern California on Sunday, with forecasters warning of significant rainfall, snow, thunderstorms, debris flows and mudslides.

Meteorologists with the U.S.' National Weather Service indicate that gusts became a mild cold front last Saturday evening, turning into a powerful storm and becoming even stronger on Monday, and that rains are expected to follow quickly.

The storm puts California's central coast at risk of "significant flooding," and thunderstorms in the valleys around Sacramento, the capital of California, could bring "brief tornadoes, large amounts of small hail, heavy rain, lightning, and gusty winds," according to the weather service office.

Forecasters compared the wet winter storm with the devastating atmospheric river which hit Southern California in early February, causing floods and hundreds of landslides with casualties. The meteorologists also said that, though it is not the ideal setup for an atmospheric river, it is strong enough to cause problems including flooding and power outages if the cold front persisted.

California Governor Gavin Newsom activated his state's operation center to help coordinate local, state and federal response to the storm on February 18. He also directed the California Governor's Office of Emergency Services (Cal OES) to strategically pre-position swift water rescue crews and other rescue personnel and equipment in multiple counties to be able to respond if needed, according to the California government's official website.

A winter storm also hit parts of northeastern U.S., with more than 30 centimeters of snow reported in Pennsylvania and New Jersey, including snowfall rates of up to 10 centimeters per hour. The storm also brought a drop in temperature to an average of -12 degrees Celsius.

(With input from agencies.)