A bomb cyclone is knocking out power and disrupting travel in the Northeast

(CNN) — Winds as strong as those in a tropical storm are pummeling New England on Thursday morning as a storm known as a bomb cyclone knocks out power and promises to disrupt travel in the region through the end of the workweek.

The storm “is now parked over southern New England with the pressure equivalent to a Category 2 hurricane,” CNN meteorologist Dave Hennen said.

More than 550,000 customers from New York to Maine are without electricity, according to PowerOutages.us. And at least 50 flights have been canceled Thursday at Boston Logan International Airport, FlightAware.com reports, with more delays and cancellations expected through late Friday.

TRACK THE BOMB CYCLONE

Wind gusts of 40 to 50 mph are expected to punish New England for much of Thursday, while New York City, Boston and Portland, Maine, may feel winds of at least 39 mph — the low end tropical-storm-force — with stronger gusts.

Provincetown, on Massachusetts’ Cape Cod, already has been lashed with winds of 90 mph. Boston Logan recorded gusts of 70 mph overnight into Thursday, and gusts atop Mount Washington in New Hampshire were clocked at 125 mph.

A wind warning or advisory covers nearly 63 million people in 14 states, from the Appalachians in North Carolina to Maine.

Even as rain from the bomb cyclone pushes out on Thursday, flood watches and warnings remain in place across much of New England.

Bomb cyclone breaks records

A bomb cyclone is a storm that strengthens really fast. To earn the title, its pressure generally must drop 24 millibars (a unit that measures pressure) within 24 hours. The word “bomb” is used because of the explosive power these storms derive from rapid pressure drops.

The storm now hammering the Northeast blew well past meteorologists’ standard: Its pressure dropped 24 millibars in just 14 hours — and plummeted 35 millibars over 24 hours.

Indeed, the system broke low-pressure records for October in Boston; Providence, Rhode Island; Hartford, Connecticut; and Portland.

The storm’s heaviest rain fell in upstate New York, where up to 5 inches was recorded. The Mid-Atlantic states and much of the Northeast got 1 to 2 inches of rain.

Eastern US dips into chillier temperatures

High temperatures Thursday for the eastern half of the United States will be 5 to 10 degrees Fahrenheit below average as a cold front pushes in. That could turn lingering rain to snow in upstate New York.

Get the latest forecast and weather stories

The bomb cyclone is the second coastal storm to impact New England in a week. Last week’s storm sat off the coast of the Mid-Atlantic, churning up seas and bringing a strong onshore wind that shredded beaches up and down the East Coast. It caused costly damage due to beach erosion and coastal flooding.

Notice: you are using an outdated browser. Microsoft does not recommend using IE as your default browser. Some features on this website, like video and images, might not work properly. For the best experience, please upgrade your browser.