‘Bomb Cyclone’: Rare Snow in South as North Braces for Bitter Cold
Posted January 3, 2018 4:49 p.m. EST
Updated January 3, 2018 4:54 p.m. EST
A powerful winter storm dealt a chilly blow to the Southeastern United States on Wednesday, as Floridians marveled at the rare sight of accumulating snow and officials around the region warned of icy roads and dangerously low temperatures — all while residents of the Northeast prepared for whiteout conditions and potential power failures caused by whipping coastal winds.
The storm, referred to by some meteorologists as a “bomb cyclone” for its sudden drop in atmospheric pressure, forced flight cancellations up and down the East Coast, and was expected to bring more headaches to the upper South and Northeast beginning Wednesday night, when New York City is forecast to receive 4 to 6 inches of snow.
A winter storm warning has been issued by the National Weather Service for parts of New York, New Jersey and Connecticut, with heavy snowfall and wind chills of up to 25 below zero expected. Gov. Terry McAuliffe of Virginia on Wednesday declared a state of emergency in the commonwealth, where up to a foot of snow is predicted in places.
The Savannah/Hilton Head International Airport in Georgia and the Charleston International Airport in South Carolina closed Wednesday morning as the storm hit. Airlines have canceled many flights to and from destinations along the East Coast and warned that their schedules could face continued disruptions.
It was 35 degrees in Jacksonville, Fla., and New Orleans; 23 degrees in Jackson, Mississippi; 28 degrees in Atlanta; and 14 degrees in the Raleigh-Durham area of North Carolina, as of about 7:30 a.m. Wednesday. It was the coldest it has been in Raleigh-Durham in more than 130 years. A temperature of 9 degrees at the area’s airport tied a record low set in 1887, the National Weather Service said.
So, what’s this about a ‘bomb cyclone’?
When discussing the storm, some weather forecasters have referred to a “bomb cyclone.” Calling it a “bomb” sounds dire, but those kinds of storms are not exceedingly rare — there was one in New England recently.
What makes a storm a “bomb” is how fast the atmospheric pressure falls; falling atmospheric pressure is a characteristic of all storms. By definition, the barometric pressure must drop by at least 24 millibars in 24 hours for a storm to be called a bomb cyclone.
Here is how it works: Deep drops in barometric pressure occur when a region of warm air meets one of cold air. The air starts to move, and the rotation of the earth creates a cyclonic effect. The direction is counterclockwise in the Northern Hemisphere (when viewed from above), leading to winds that come out of the northeast — a nor’easter.
That’s what happened at the end of October, when warm air from the remnants of a tropical cyclone over the Atlantic collided with a cold front coming from the Midwest. Among other impacts then, more than 80,000 electric customers in Maine lost power as high winds toppled trees.
A similar effect is expected late Wednesday, as warm air over the ocean meets extremely cold polar air that has descended over the East. Pressure is expected to fall quickly from Florida northward.
New York and the Northeast can expect frigid and snowy conditions.
As much as 280,000 tons of salt. More than 2,200 snow plow trucks. About 2,400 sanitation workers. That’s how New York City is bracing for the “bomb cyclone” forecast to hit the city late Wednesday.
“We are going to have exceptionally strong winds,” said Kathryn Garcia, commissioner of the Department of Sanitation. “Anything that is falling is likely to float around and drift.”
Garcia encouraged New Yorkers to avoid driving and use mass transit instead.
“The high winds and very low temperatures mean that we are going to be operating in near whiteout conditions,” Garcia said.
The city will open an emergency operation center at 9 p.m., said Herman Schaffer, assistant commissioner of the Office of Emergency Management.
“We are asking everyone that you please stay off the roads unless you need to be on the roads,” Schaffer said. “The major snows are going to be happening during tomorrow’s morning rush hour.”
Schaffer also encouraged residents to check up on their neighbors and make sure they were ready to brace for the negative temperatures in the days after the storm.
For Bostonians, Wednesday’s forecast high of 28 degrees was almost a relief after days of temperatures that hovered in or near the single digits. But it was quite literally cold comfort, with Thursday’s storm expected to drop 8 to 12 inches of snow on the city and potentially create blizzard conditions up and down the New England coast.
The National Weather Service posted winter storm warnings beginning at 1 a.m. Thursday for a broad swath of Massachusetts and all of Rhode Island, and a blizzard warning stretched along the coast, from Newport, Rhode Island, to the Canadian border, although it excluded Cape Cod.
Mayor Martin J. Walsh of Boston said schools would be closed Thursday and urged employers to let their employees work from home if possible. Swiftly falling snow was likely to keep roads clogged during some parts of the day, Walsh said, even though workers planned to treat roads before the snow began and use 700 pieces of equipment to clear them during the storm.
“We could be plowing and a half-hour later it’ll look like we didn’t touch the street,” Walsh said. The biggest challenge with Thursday’s storm, he said, was the frigid weather that is expected to follow.
The deep cold of recent days has already taxed transit systems, fuel supplies and homeless shelters in New England. And it has turned many of the region’s harbors to ice.
“Oh yeah, we’re frozen solid,” said Dawson Farber, the harbor master in Dennis, Massachusetts, who said the harbor looked like “a huge saltwater skating rink right in front of my window.”
The Mid-Atlantic region is facing blizzard conditions.
The National Weather Service said a blizzard warning would take effect along the Virginia coast later Wednesday.
“Travel will be very dangerous to impossible,” forecasters wrote in their warning for the highly populated Hampton Roads region of Virginia, which they said could expect 5 to 8 inches of snow, with up to 12 inches in some areas.
The Weather Service said wind gusts could reach 50 mph and that they could “cause whiteout conditions in blowing snow” in and around Norfolk and Virginia Beach.
In Baltimore, the president of the Teachers Union on Wednesday urged administrators to close schools in the district, citing heating problems amid freezing temperatures. Four schools in the city were already closed Wednesday, and three more released students early.
“Our educators have been forced to endure teaching in classrooms with dangerously low temperatures, instructing students who have been forced to try to learn bundled up in coats, hats and gloves,” wrote Marietta English, the union’s president, in a letter that was delivered to school leadership and published online by The Baltimore Sun.
Washington, too, remained firmly in the grip of a winter that has already proved treacherous. The District of Columbia government activated its cold emergency plan on Dec. 27, and on Wednesday, it extended it further. Washington’s strategy calls for emergency shelters and for officials to provide transportation to “warmth and safety.”
On Wednesday morning, city firefighters were breaking ice along a segment of the Potomac River that divides Virginia and the District.
Snow is falling in some unlikely places.
Tallahassee, Florida’s capital, sees flurries every few years, said Mark Wool, a meteorologist with the National Weather Service’s Tallahassee office. But the tenth to two-tenths of an inch of snow recorded Wednesday? Not since 1989.
The dusting, which was preceded by a couple of hours of freezing rain, lasted about an hour. It was over by about 9 a.m., though more snow was falling just north of Tallahassee, in southern Georgia. Chris Jones, the fire chief in Thomas County in southern Georgia, said the snowfall was brief there, too.
A handful of school districts in North Florida that had already resumed classes after winter break, including in Tallahassee and Gainesville, had previously closed. It is the second time in recent months that many children in the area will lose school days because of the weather: Hurricane Irma forced shutdowns in September.
In Charleston, South Carolina, about 5,000 people were without power after a morning bout of freezing rain left power lines, mossy oaks and palm trees coated with an uncharacteristic glaze of ice. By 1 p.m. the icy rain gave way to heavy snow — expected to fall at the rate of an inch an hour through the evening.
At a grocery store in the Folly Beach neighborhood, Chris Brown, a father of two daughters, stocked up on food to prepare to be snowed in. “It’s blowing up,” he said of the snow. “I can’t believe how heavy it is. I’m heading home to play with the kids.”
An ER doctor in Atlanta says ‘this is the most challenging winter.’
The new round of shivering prolonged what has already been a difficult period in the country’s emergency rooms. In the Atlanta area, where temperatures were hovering around freezing Wednesday but were expected to plunge into the teens after nightfall, doctors said they had been seeing an unusual number of patients with weather-related emergencies.
“This is the most challenging winter, in terms of exposure, that I’ve ever seen,” said Dr. Brooks Moore, the assistant medical director of the emergency department at Grady Memorial Hospital, Atlanta’s public hospital.
Moore said about 20 people were arriving at the emergency room each day with minor complaints related to the weather, and that about the same number were appearing with conditions like asthma or emphysema that were exacerbated by the cold.
He added that doctors were seeing about one or two patients a day whose core body temperatures had fallen into the low 80s — normal is about 98.6 degrees — and required “aggressive re-warming” techniques.
Southern governors warn residents to stay safe.
Gov. Roy Cooper of North Carolina said on Wednesday he would declare an emergency in places forecast to be affected by the storm, including eastern counties unused to snow. Up to 8 inches are expected in Camden and Currituck counties, in the state’s northeastern edge.
“What I worry about are people in their homes who may lose power and may lose the ability to heat their homes,” Cooper said.
His administration is providing four-wheelers and Humvees to local governments to help people who might get stranded. State troopers are marking abandoned cars along roads to ensure no one is left stranded.
“The good news is that the storm is moving quickly and should be gone by Thursday evening,” the governor said. “The bad news is that we will have unusually cold temperatures sticking around for several days.”
On Tuesday, Gov. Nathan Deal of Georgia declared an emergency for 28 counties along or near the state’s southeastern coast. Deal’s declaration includes Chatham County, home to about 289,000 people.
Deal was among the Georgia politicians who received criticism after a winter storm paralyzed Atlanta in 2014. In a statement Tuesday evening, he noted that the state Department of Transportation had sent all of its brine trucks, as well as 75 plows, to southeast Georgia.
“I encourage all Georgians in the potentially impacted areas to stay informed, get prepared and be safe,” he said.
What’s happening to the birds that flew south for the winter?
Geoff LeBaron, director of Audubon’s Christmas Bird Count, a kind of early-winter bird census that has been taking place since the year 1900, said that, fortunately, birds that could not effectively withstand cold snaps were already farther south than the continental United States.
“Warblers, thrushes, tanagers, they’re down in Central and South America,” he said. “The birds that winter in the Southern U.S. are better able to withstand the temperatures and have more flexibility in terms of the food they can eat.”
LeBaron said that waterfowl and marsh birds might be affected if there was significant snow cover or if water sources were frozen over.
And he warned that the increasing number of hummingbirds that spend the winter in the South might be affected, and said that people who maintain the birds’ feeders should keep the feeders warm and well supplied.
But he said that the short amount of time the cold was expected to last would allow others to scrounge through.
“The birds that are wintering down there are going to have to hunker down and deal with the conditions,” he said.
Just like the humans.