'Double whammy' of extreme weather grips both US coasts

NEW YORK - Heavy rain and snow wreaked havoc across the northeastern United States, sparking flood warnings and power outages, as extreme weather gripped both American coasts.

The "double whammy," as the National Weather Service called it, is the latest in an unusual series of weather fronts to have rocked the United States simultaneously.

It is hard to establish a direct link between these winter storms, but scientists say human-caused climate change, brought about by the unchecked burning of fossil fuels, is making them wetter and wilder. 

New York and New Jersey declared states of emergency to free up additional resources, as a powerful coastal storm called a "nor'easter" barreled across the region and New England.

Precipitation and strong winds knocked out power to more than 230,000 homes across New York, Massachusetts, New Hampshire, Vermont and Connecticut, according to PowerOutage.us.

More than 15 million people across the northern Atlantic seaboard were under a winter storm warning Tuesday morning, with the National Weather Service (NWS) warning of widespread minor coastal flooding and tree damage.

New York governor Kathy Hochul said the snow was going to "come down like a brick," as she urged residents not to leave their homes on Tuesday.

"This will be a dangerous storm," she said Monday, warning of up to 20cm of snow in some areas and wind gusts of 72km/h.

Multiple schools were closed in areas of Massachusetts and in New Hampshire, where dozens of local elections were postponed.

The storm, which arrived late Monday and is expected to cause hazardous conditions until it leaves the region on Wednesday, also impacted flights.

New York City's LaGuardia airport tweeted that the weather had caused flight "disruptions" while a plane carrying 61 passengers skidded off a runway in Syracuse airport in upstate New York.

The operator of the airport, where several flights were cancelled, did not say whether the incident had caused any injuries.

Nearby Monroe County, next to the border with Canada, had recorded the highest snowfall in New York state as of Tuesday morning with nine inches falling overnight.

On the other side of the country, the NWS warned that there was a "high risk of excessive rainfall" over parts of central and southern California from Tuesday to Thursday.

The weather service said the precipitation, combined with snow melt in lower terrains, could cause "widespread flooding," in areas already too wet to absorb any more water.

A parade of storms have pummeled California this winter, causing hundreds of millions of dollars of damage as they washed out communities, brought down power lines and caused landslides.