A powerful nor'easter is rolling through the East Coast for the second time in less than a week, bringing another round of blackouts, treacherous roads and canceled flights.

The storm dumped snow in several states, including New York, New Jersey and Pennsylvania -- before it shifted its focus to New England on Thursday, where it'll linger for a day.

About 19 million people, from Connecticut to Maine, remained under winter storm warnings and watches after a deadly "bomb cyclone" hit the area last week. But this storm is less severe and not a repeat of the previous one on March 2, which left at least six people dead.

Snow and rain remain a concern, along with the aftermath of fallen trees, knocked out power lines and slippery roads.

Here's what to expect:

Focus is on New England

The storm has mostly passed in most areas in the Northeast. While it's not as strong as last week's as far as wind and waves, it will produce a lot of snow, CNN meteorologist Michael Guy said.

"New England will still be feeling the effects of the wind and residual snowfall (though light) through Friday," Guy said.

It will be a messy mix of snow and rain moving into central New England during the next few hours,the National Weather Service said early Thursday.

"Rain is changing to snow across southeastern Massachusetts and Rhode Island," it said.

Snow is still falling

When it comes to snowfall, New York should breathe a sigh of relief. While snow continued to fall there overnight Thursday, it should be "completely out of the region" by morning, according to the weather service.

But parts of New England will see heavy to moderate snow overnight into Thursday morning, forecasters said. It will stay the longest over eastern New England, which will see manageable light snow as late as noon.

Massachusetts Gov. Charlie Baker urged residents to use caution and stay off the roads during the height of the storm.

The Boston area is forecast to receive 6 to 8 inches of snow by Thursday morning, and Mayor Marty Walsh announced public schools will be closed that day.

More blackouts

Winds and snow are bringing down more power lines, piling on to the crippling outages remaining from last weekend's storm.

By late Wednesday night, there were about 329,000 customers without power, from Virginia to New England.

The storm is expected to pack wind gusts of 30 mph to 50 mph. While a far cry from the 90-mph gusts recorded during the weekend storm, they could impede efforts to restore power in the region.

The heavy, wet snow is not helping either, combining with the strong winds to heighten the risk of downed power lines and as a result, blackouts to more homes and businesses.

Hardest-hit states

In Pennsylvania, Philadelphia was forecast to get between 6 to 8 inches Wednesday, according to the National Weather Service. Pennsylvania Gov. Tom Wolf announced a state of emergency for several counties.

In New York, the town of Sloatsburg topped the list of most snowfall Wednesday night, with 26 inches within 24 hours, according to the National Weather Service.

Gov. Andrew Cuomo deployed 400 National Guard troops to conduct wellness checks and assist with storm recovery.

In addition to the snow, Boston faces coastal flooding Thursday due to high tide, the National Weather Service said.

"Already observing an over 3-foot storm surge at Boston; obvious concern with onshore wind gusts upon a weakened, vulnerable shoreline," it tweeted.

The snowstorm also brought a rare phenomenon in some parts of Pennsylvania, New Jersey and New York, the weather service said. Known as "thundersnow," it's snow paired with lightning and resulting thunder.

Travel headaches

More than 400 flights -- including at airports in New Jersey, New York, Boston and Philadelphia -- were canceled by early Thursday, according to FlightAware.

As for ground travel, New York City's Office of Emergency Management issued a hazardous travel advisory urging residents to "take mass transit if possible and allow for extra travel time."

Amtrak has also canceled some services in affected areas.

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