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Capital Weather Gang

'Bomb cyclone' blasting East Coast before polar vortex uncorks tremendous cold late this week

By Jason Samenow

January 3, 2018 at 4:18 PM

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Record cold temperatures are affecting much of the U.S. The weather may be brutal, but it can also be beautiful. (Taylor Turner/The Washington Post)

(This story, first published Tuesday afternoon, was fully updated late Wednesday afternoon with the latest forecast information.)

Unforgiving cold has punished the eastern United States for the past 10 days. But the most severe winter weather yet will assault the area Wednesday night into the weekend.

First, a monster ocean storm is taking shape, which pasted parts of Florida, Georgia and South Carolina with rare ice and snow early Wednesday. By Thursday, the exploding storm will, in many ways, resemble a winter hurricane, battering easternmost New England with potentially damaging winds in addition to blinding snow. Blizzard warnings have been issued for the Virginia Tidewater region up the coast to eastern Maine, including Ocean City, Atlantic City, eastern Long Island, Boston and Portland.

“This rapidly intensifying East Coast storm will produce strong, damaging winds — possibly resulting in downed trees, power outages and coastal flooding,” the National Weather Service tweeted Wednesday.

Related: [Watch: ‘Bomb cyclone’ moves toward east coast]

Forecasters are expecting the storm to become a “bomb cyclone” because its pressure is predicted to fall so fast, an indicator of explosive strengthening. The storm could rank as the most intense over the waters east of New England in decades at this time of year.

National Weather Service hurricane hunter aircraft are even flying into the storm to gather data and refine the forecast given the possible severe impacts in coastal areas.

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TV reporters and social media users are testing the freezing temperatures with some old tricks. (Elyse Samuels/The Washington Post)

In the storm’s wake, the mother lode of numbing cold will crash south — likely to be the last but most bitter in brutal blasts since Christmas Eve in the Northeast.

Related: [Major winter storm threatens East Coast with snow, bone-chilling cold]

The storm: How much snow and wind, and where

The storm took shape off the coast of Florida on Wednesday, unloading hazardous snow and ice in highly unusual locations not accustomed to such weather.

It is next expected to rapidly intensify, buffeting the Mid-Atlantic beaches and eastern New England.

On Wednesday morning, as many as six inches of snow and 0.5 inches of ice caked portions of north Florida, southeast Georgia and coastal South Carolina. In Tallahassee, it was snowing for the first time in 28 years.

Meanwhile, in Savannah, ice changed over to snow, offering a rare coating on the region’s palmetto trees. More than an inch accumulated, one of the snowiest days in the city’s history.

The Weather Service issued a rare alert for “heavy freezing rain” along the entire South Carolina coast Wednesday morning before the precipitation turned over to snow during the afternoon. In Charleston, the Weather Service reported the snow was “pouring”. Ultimately, it piled up to 5 inches, making Wednesday the city’s third snowiest day on record.

From Norfolk to the Maryland and Delaware beaches, under blizzard warnings, at least 5 to 8 inches of snow is predicted, with as much as a foot possible between Wednesday evening and Thursday afternoon. The combination of wind gusts up to 50 mph and heavy snow could cause whiteout conditions. It is only the second blizzard warning for the Virginia Tidewater since the 1980s.

Farther inland in the Mid-Atlantic, near Interstate 95, up to an inch or so could fall in Washington and Baltimore, but more in their eastern and southeastern suburbs, where several inches are predicted.

Related: [Big ocean storm to brush D.C. area with a dusting to a few inches of snow, heaviest in eastern areas]

To the north, Philadelphia and New York are both under winter storm warnings late Wednesday night through Thursday for 5 to 8 inches of snow and wind gusts up to 45 mph.

East of Philadelphia and New York, predicted snow amounts and wind speeds increase. Atlantic City is expecting 6 to 10 inches of snow and wind gusts to 50 mph, while eastern Long Island may endure 8 to 12 inches of snow and 55 mph gusts.

Specific amounts up and down the coast will depend on the exact storm track. If the storm tracks closer to the coast, snow amounts and peak wind gusts will be higher and extend farther west. But if the storm wobbles east, snow amounts as well as peak winds will decrease.

By the time the storm reaches the ocean waters off eastern New England on Thursday, it will have explosively intensified and become a more severe storm. Its central pressure will have fallen almost 50 millibars in just 24 hours — an astonishing rate of strengthening.

European model simulation of storm pressure drop between Wednesday and Thursday. (, adapted by CWG/)

“Some computer models are projecting a minimum central air pressure of below 950 millibars at its peak, which would be nearly unheard of for this part of the world outside of a hurricane,” wrote Mashable’s Andrew Freedman. “For comparison, Hurricane Sandy had a minimum central pressure of about 946 millibars when it made its left hook into New Jersey in 2012.”

It is this drop in pressure that will cause winds to really crank up in eastern New England, up to 60 to 70 mph along the coast. Winds will be considerably stronger over the ocean — exceeding hurricane force — where enormous waves will form.

In Boston, the Weather Service is forecasting up to 14 inches of snow Thursday, along with 60 mph wind gusts strong enough to bring down branches and cut power.

In both eastern Massachusetts and Maine, the combination of potentially damaging winds and heavy snow is expected to cause whiteout conditions and significant drifting of snow. Thunder could accompany the snow and fall at a clip of up to 2 to 3 inches per hour.

As the wind and waves slam into the shore, coastal flooding is forecast Thursday late morning and afternoon, raising seas 2 to 2.5 feet above normal, with “moderate to major impacts,” according to the Weather Service, inundating shore roads and basements. “In a few spots, sea ice chunks may exacerbate damage,” it said.

The Weather Service expects to snow to result in “extremely difficult” travel, but it is most concerned about the power outage threat and the bitter cold predicted to follow.

The cold in its wake: record-breaking

Temperature difference from normal forecast Saturday morning by American (GFS model. Note these are deviations from average, not actual temperatures./)

The storm’s enormous circulation will help draw several lobes of the polar vortex, the zone of frigid air encircling the North Pole, over the Mid-Atlantic and Northeast by Friday and Saturday. Wicked cold air sourced from Siberia, the North Pole and Greenland will all converge on the region.

Temperatures are forecast to be 20 to 40 degrees below normal, the coldest of the winter so far.

Most locations in the Mid-Atlantic and Northeast are predicted to set records for cold temperatures Friday, with highs in the single digits and teens.

Forecast highs on Friday from the National Weather Service. Those circled are forecast to be within a degree of a record low. (

On Saturday morning, subzero cold is forecast over almost all of New England, with single digits in the Mid-Atlantic.

Forecast lows predicted by National Weather Service Saturday. Those circled are predicted to within a degree of the record low. (

Winds, gusting to 30 mph, will make these areas feel 10 to 20 degrees colder.

Top wind gust is forecast for Friday evening from the American (GFS model./)

Finally, after one of the most intense cold spells of such duration on record in parts of New England — including Boston — temperatures are forecast to thaw by early next week.

A farmer feeds his cattle as a light snow begins to fall in Myersville, Md.
US Vice President Mike Pence's limos are seen with their windshield wipers up before an ice storm January 8, 2018 in Washington, DC. / AFP PHOTO / Brendan SmialowskiBRENDAN SMIALOWSKI/AFP/Getty Images
Cassia Denton jumps in the air from the frozen Lincoln Memorial Reflecting Pool.
CLARKSBURG, MD -JAN 08: Jamal Richardson admitted that the road and sidewalk surfaces were a bit slick today but he had the help of his sure-footed four-legged jogging partner named Duke. They are on Little Seneca Parkway in Clarksburg, Maryland. (Photo by Michael S. Williamson/The Washington Post)
People are seen bundled up near the Lincoln Memorial.
People skate at the Chesapeake and Ohio Canal National Historical Park in Washington.
Children skate at the Chesapeake and Ohio Canal National Historical Park in Washington.
Sabrina Spracklen of the U.S. Naval Academy is seen with others at the Lincoln Memorial while on a squad run.
The Jefferson Memorial is reflected on the frozen Tidal Basin at sunset.
A water leak causes a slippery layer of ice on the road at Dupont Circle.
The Tidal Basin is frozen after days of below freezing temperatures.
The Tidal Basin near the Jefferson Memorial.
The temperature is displayed at a Dupont Circle bank. Commuters and pedestrians have faced temperatures way below the freezing point in the early mornings.
Construction crews from Fort Myer Construction and the D.C. Water and Sewer Authority work on a broken water main pipe on 27th Street NW.
Anna Compton bundles up for the cold as she crosses K Street near Farragut Square.
A homeless person’s tent is seen downtown.
Despite the cold weather, tourists have photos taken on the steps of the Lincoln Memorial.
A Metro employee cleans the stairs at the Smithsonian Metro station during the early morning commute.
Early morning at the Mall.
Diego Vazquez gets a push from his mother Genevieve Vazquez in an attempt at sledding in a light snowfall on the west front of the Capitol.
People walk alongside a frozen Lincoln Memorial Reflecting Pool on the Mall.
This aerial photograph shows snow in Washington. A giant winter “bomb cyclone” walloped the East Coast on Thursday with freezing cold and heavy snow, forcing thousands of flight cancellations and widespread school closures — and even prompting the Senate to cancel votes for the rest of the week.
Dock hand Melvin Castellon breaks up ice around a dock at the Washington Sailing Marina in Alexandria.
An aircraft takes off from Reagan National Airport, as seen from the Washington Sailing Marina in Alexandria.
A boat sits in ice while docked on the Alexandria waterfront near Founders Park.
The Thurgood Marshall Memorial Lawyers’ Mall withstands the chilly temperatures outside the statehouse in Annapolis, Md.
Christian Fay, 21, of Laytonsville, Md., plays hockey on Brinkwood Pond in Montgomery County. The makeshift rink has about a foot of ice covering it, twice the depth required for safe skating.
A pedestrian walks through steam along 10th Street NW.
People wait to cross 17th Street NW as they walk along L Street.
On a frigid day in the Rosslyn area of Arlington, Va., Patty Lopez, center, takes a break from work.
People skate at the National Gallery of Art Sculpture Garden rink in Washington.
Jason Haynes, left, and Nicholas DePhillip interact with gulls in the snow at the Thomas Jefferson Memorial in Washington.
Ginna Altmeyer and Will Wetzel take wedding photos in the snow at the Thomas Jefferson Memorial before their ceremony at Holy Rosary Church. Of the snow, Altmeyer said, “I love it. It makes it the picture-perfect D.C. winter wedding.” She was told that snow on one’s wedding day is lucky.
A collection of coffee cups are piled up by visitors as they walk to see the White House.
Ganesh Puri, left, tosses bread to geese chilling in a pond in the Flower Hill neighborhood of Gaithersburg, Md.
Geese that opted to stay local and not head south float in a pond in the Flower Hill neighborhood.
A squirrel enjoys a piece of frozen pizza crust while straddling on a fence just past sunrise in Gaithersburg.
A pedestrian walks by a group of homeless folks on the 1300 block of K Street NW.
WASHINGTON, DC -DEC 29: Dion Druz shivers in the cold as he rests on the sidewalk on the 1300 block of K street NW. He has a variety of reasons that he doesn't like the shelters including the fact he once got bed bug bites at the shelter. -For a variety of reasons, some homeless folks on the streets of Washington, D.C. opt to stay on the streets in the fierce cold weather rather than stay in a homeless shelter. (Photo by Michael S. Williamson/The Washington Post)
A woman who goes by the name Seal takes a smoke break after visiting the tent belonging to a fellow homeless person named Dreds.
Evan Graham, right, with fellow homeless campers Ernesto and Mario, center, said that it would have to get much colder than it is now for him to go into a homeless shelter. Some people who stay at the shelter make him uncomfortable and he doesn’t like what he feels are restrictive rules, he said.
Homeless residents of the district huddle amid blankets on the sidewalk along K Street NW as the sun rises.
A pedestrian covers her head along Indiana Avenue NW.
Pedestrians make their way along Indiana Avenue NW.
Pedestrians walk down Seventh Street NW.
People brave the cold as they ride on an open-air tourism bus making its way down the Mall.
Visitors to the Washington Monument brave temperatures in the teens.
A woman braves the cold on her way to the National Museum of African American History and Culture.
Tourists bundle up to visit the Mall near the Capitol.
Tourists visit the Mall despite the cold.
Photo Gallery: Residents and tourists alike face frigid temperatures in the DMV.

Jason Samenow is The Washington Post’s weather editor and Capital Weather Gang's chief meteorologist. He earned a master's degree in atmospheric science and spent 10 years as a climate change science analyst for the U.S. government. He holds the Digital Seal of Approval from the National Weather Association.

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Capital Weather Gang

'Bomb cyclone' blasting East Coast before polar vortex uncorks tremendous cold late this week

By Jason Samenow

January 3, 2018 at 4:18 PM

Watch more!
Record cold temperatures are affecting much of the U.S. The weather may be brutal, but it can also be beautiful. (Taylor Turner/The Washington Post)

(This story, first published Tuesday afternoon, was fully updated late Wednesday afternoon with the latest forecast information.)

Unforgiving cold has punished the eastern United States for the past 10 days. But the most severe winter weather yet will assault the area Wednesday night into the weekend.

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