Follow Thursday’s updates here: Hurricane Florence set to unleash punishing wind and rain in the Carolinas

Decreasing in strength but expanding in size, Category 2 Hurricane Florence is within 36 hours of making landfall on the Southeast coast with potentially catastrophic impacts, from damaging winds to flash flooding to widespread power outages.

The storm’s surge, the rise in seawater above normally dry land at the coast, could reach up to 13 feet at peak. Hurricane-force winds will bring down trees and damage homes and businesses. Like Hurricane Harvey in 2017, Florence is expected to slow significantly when it reaches the coast, allowing the storm to dump a disastrous amount of rain in the Carolinas.

Although Florence’s peak winds decreased some Wednesday, from 130 to 110 mph, the National Hurricane Center said the storm increased in size and energy, “which will create a significant storm surge event.”

“This will likely be the storm of a lifetime for portions of the Carolina coast,” the National Weather Service in Wilmington, N.C., wrote Tuesday, “and that’s saying a lot given the impacts we’ve seen from hurricanes Diana, Hugo, Fran, Bonnie, Floyd, and Matthew.”

Forecasts project  the center of Florence to make landfall Friday around the border of the Carolinas as a Category 2.

As it nears the coast, the storm’s forward motion will slow to a crawl, but the winds and rain will be relentless.

Since Tuesday, forecasts have shifted the storm track toward  the south and southwest after it reaches the coast, which could increase the storm’s severity in coastal South Carolina through Myrtle Beach and Charleston and even into parts of Georgia.

Due to unusual steering patterns in the atmosphere, Florence may drift southward down the Southeast coast, the opposite direction storms usually travel.

“There’s virtually no precedent for a hurricane moving southwest for some time along the Carolina coast,” tweeted Bob Henson, meteorologist at Weather Underground. “Such an unorthodox track could produce some very unexpected outcomes.”

The Hurricane Center is warning of a triple threat in the Carolinas:

  1. A “life-threatening storm surge” at the coast — a tsunami-like rise in ocean water over normally dry land
  2. “Life-threatening freshwater flooding from a prolonged and exceptionally heavy rainfall event” from the coast to interior sections
  3. “Damaging hurricane-force winds” at the coast and some distance inland

Like Hurricane Harvey, which stalled over Texas in 2017, Florence could linger over the Southeast for several days after landfall, unloading 20 to 30 inches of rain in coastal North Carolina and isolated amounts of up to 40 inches. Flooding from heavy rains is the second-leading cause of fatalities in tropical storms and hurricanes that make landfall.

Enough rain could fall to break North Carolina’s record for a tropical storm — 24 inches — set near Wilmington during Hurricane Floyd in 1999, said Greg Carbin, chief of forecast operations at the Weather Service’s national prediction center.

More than 1.5 million people have been ordered to evacuate coastal areas ahead of the storm because of both destructive winds and a storm surge that could place normally dry land under at least 10 feet of water.

“All interests from South Carolina into the Mid-Atlantic region should ensure that they have their hurricane plan in place and follow any advice given by local officials,” the Hurricane Center said.

What you need to know
The latest | Storm hazards | Storm timing | Path projections | Florence’s place in history

The latest

News

“North Carolina, my message is clear,” a grim Gov. Roy Cooper said at a briefing Wednesday. “Disaster is at the doorstep and is coming in.”

The pivot in the forecast track of Florence led Georgia’s governor to declare a state of emergency Wednesday afternoon for all 159 counties, home to 10.5 million people.

And it led to mixed signals from officials in South Carolina, whose governor had canceled mandatory evacuation for several coastal counties  Tuesday. Wednesday, officials in Beaufort County, home to Hilton Head Island, held a news conference and urged people to leave voluntarily.

Federal officials warned that the millions of people in Florence’s sights could be without electricity for weeks, if high winds down power lines and massive rainfall floods equipment. There are 16 nuclear reactors in the region, and crews at the one closest to where landfall is forecast readied the station, at Brunswick, for a shutdown.

The monstrous storm has forced the closing of hundreds of schools throughout the region. Because Florence’s rainfall is expected to pound areas far from the coast, the University of North Carolina at Chapel Hill, Duke and North Carolina State universities canceled classes through week’s end. Boeing and Volvo shut down their Charleston factories, idling thousands who build 787s and sedans.

President Trump has approved emergency disaster declarations for the Carolinas and Virginia, which frees up funds for relief and recovery. “We’re as ready as anybody has ever been,” he said after a briefing with Federal Emergency Management Agency Administrator William “Brock” Long and Homeland Security Secretary Kirstjen Nielsen.

He also canceled campaign rallies in Cape Girardeau, Mo., and in Mississippi.

“Florence could be the most dangerous storm in the history of the Carolinas,” Long, a North Carolina native, tweeted Tuesday.

Weather

As of 11 p.m. Wednesday, Florence’s top winds were 110 mph, and it was barreling northwest at 17 mph, about 280 miles east-southeast of Wilmington.

The Hurricane Center predicts the storm to maintain this intensity until landfall, after which the top winds will steadily decrease.

Within the northeast section of the storm, the Hurricane Center reported wave heights up to 83 feet Wednesday morning.

Even as Florence’s peak winds decreased, the storm’s wind field continued growing Wednesday, the Hurricane Center said. Hurricane-force winds extend 80 miles from the center, while tropical-storm-force winds extend 195 miles outward. The storm’s cloud field is about the size of four Ohios.

Hurricane warnings are in effect for the South Santee River in South Carolina to Duck, N.C, and Albemarle and Pamlico sounds. This includes Wilmington, N.C. Hurricane watches extend north to the North Carolina-Virginia border and south to the South Santee River, including the Charleston area. A tropical storm warning covers the area from north of Duck, N.C., to the North Carolina-Virginia border.

More than 10 million people are under watches and warnings, the Associated Press reported.


(National Weather Service)

Storm timing

In coastal areas of the Southeast and Mid-Atlantic, heavy surf and elevated water levels are expected to arrive by Wednesday morning, and rainfall could begin by late Wednesday night and Thursday morning. The rain is then predicted to spread inland by Friday and potentially continue for days as the storm slows or stalls.

Tropical-storm-force winds could reach the coastline as early as Thursday morning, at which point all outdoor preparations should be completed.

Extremely dangerous hurricane-force winds could batter coastal locations by Thursday night and Friday. Hurricane-to-tropical-storm-force winds could extend well inland, depending on the storm’s track.

Storm hazards

Storm surge

Like a bulldozer, the storm’s winds and forward motion will push a tremendous amount of water onshore when it makes landfall. The storm surge, or rise in water above normally dry land at the coast, could reach up to more than a story high, or 13 feet, if the maximum surge coincides with high tide.

Jeff Masters, the meteorologist who writes Weather Underground’s Category 6 blog, reported that a maximum surge of 15 to 20 feet is possible, which would rival heights from hurricanes Hugo (1989) and Hazel (1954).

The biggest surge should occur just to the north of where the eye of the storm comes ashore, which the Hurricane Center projects in southeastern North Carolina.

The surge will result in “large areas of deep inundation . . . enhanced by battering waves,” the Weather Service said. It warned of likely “structural damage to buildings . . . with several potentially washing away,” “flooded or washed-out coastal roads” and “major damage to marinas.”

Storm surge warnings were issued from South Santee River in South Carolina to Duck, N.C. The Charleston area is under a storm surge watch.


The Hurricane Center projects the following surge heights above normally dry land, if the maximum surge coincides with high tide:

  • Cape Fear to Cape Lookout, including the Neuse, Pamlico, Pungo and Bay Rivers: 9 to 13 feet
  • North Myrtle Beach to Cape Fear: 6 to 9 feet
  • Cape Lookout to Ocracoke Inlet: 6 to 9 feet
  • South Santee River to North Myrtle Beach: 4 to 6 feet
  • Ocracoke Inlet to Salvo, N.C.: 4 to 6 feet
  • Salvo to North Carolina/Virginia Border: 2 to 4 feet
  • Edisto Beach to South Santee River: 2 to 4 feet

Rain

Models agree that a building high-pressure zone north of the storm will cause it to slow once it reaches the coast or shortly thereafter. There is relatively strong agreement that excessive amounts of rain will fall in southeastern North Carolina.

“Floodwaters may enter numerous structures, and some may become uninhabitable or washed away,” the Weather Service warned.

Where exactly the zone of heaviest rain sets up as the storm meanders inland is highly uncertain, but models suggest that it may concentrate in southern North Carolina and northern South Carolina through the weekend.

There is some possibility that the storm will reverse course early next week and turn back north toward West Virginia, Virginia and Pennsylvania, albeit significantly weakened. This region will be particularly susceptible to flooding because of far-above-normal rainfall since May. In addition, because the ground is likely to be saturated, trees would be vulnerable in strong winds.


(National Weather Service)

The Hurricane Center forecasts these rain amounts:

  • Coastal North Carolina.: 20 to 30 inches, isolated 40 inches.
  • South Carolina, western and northern North Carolina: 5 to 10 inches, isolated 20 inches.
  • Elsewhere in the Appalachians and Mid-Atlantic states: 3 to 6 inches, isolated 12 inches. Much of this rain would fall early next week, rather than over the weekend.

Wind

The strongest winds will occur where and when the storm makes landfall in a ring around the calm eye of the storm known as the eyewall. If the storm makes landfall as a Category 2, these winds will be damaging, sustained at up to 100 mph or so with higher gusts.

The zone where these intense winds occur will be narrow, but the effects will probably be severe, similar to a  tornado. The Hurricane Center describes the types of damage associated with Category 2 winds:

Well-constructed frame homes could sustain major roof and siding damage. Many shallowly rooted trees will be snapped or uprooted and block numerous roads. Near-total power loss is expected with outages that could last from several days to weeks.

Outside this zone of destructive winds, damaging winds are still likely, even some distance inland from the coast, which would lead to minor structural damage, downed trees and widespread power outages.

A power outage model run at the University of Michigan projects that 3.2 million customers will be without electricity because of  the storm, mostly in the eastern half of North Carolina.

If the storm stalls in the eastern Carolinas as or just after it makes landfall, these wind impacts will be magnified.

The National Weather Service forecast calls for 62 straight hours of tropical-storm-force gusts, and 24 straight hours of hurricane-force gusts in Wilmington.

The latest path projections

Where the storm makes landfall has implications for where the strongest winds and biggest rise in water at the coast occurs, but strong winds and extreme rainfall could occur at great distances from the landfall location. Keeping this in mind, here is the likelihood of landfall at different locations based on our evaluation of model data:

  • 90 percent in the Carolinas
  • 10 percent elsewhere

Even in the unlikely event that the storm center remains just offshore, it will almost certainly come close enough to bring dangerous wind and flooding to coastal areas. Areas farther to the north and west may be somewhat spared in this scenario.

While it is extremely likely that the eastern Carolinas will be hard hit by the storm Thursday into Friday, the storm’s direction becomes far less certain over the weekend and next week.

“Models are indicating that the steering currents will collapse by Friday when Florence is approaching the southeast U.S. coast,” the Hurricane Center wrote. “The weak steering currents are expected to continue through the weekend, which makes the forecast track on days 3-5 quite uncertain.”

Since early in the week, the post-landfall storm track has shifted more to the south and west, possibly pushing it down the coast of South Carolina or into its interior — in the opposite direction storms normally track before most likely returning north.


A group of simulations from American (blue) and European (red) computer models from Wednesday. Each color strand represents a different model simulation with slight tweaks to initial conditions. Note that the strands are clustered together where the forecast track is most confident, but they diverge where the course of the storm is less certain. The thick bold red line is the average of all of the European model simulations, while the blue is the average of all the American model simulations. The thinner bold (red and blue) lines are the main or operational simulations from each model. (StormVistaWxModels.com)

Florence’s place in history

If Florence strengthens just slightly into a major hurricane (Category 3 or higher) and makes landfall along the Southeast coast north of Florida, the rarity of such an event is relevant. Since 1851, only 10 major hurricanes have done so, and the most recent was Fran in 1996, 22 years ago. Hugo in 1989 was the one before that and was a Category 4 at landfall. No hurricane has made landfall as a Category 5 in this region on record.

Many people in the Southeast and Mid-Atlantic probably have not experienced a storm of the potential magnitude of Florence.

Read more

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‘Nothing to play with:’ FEMA chief’s Hurricane Florence alarm draws on vivid memories of Hugo

Hurricane Isabel struck the Mid-Atlantic 15 years ago, and its memory is still fresh as Florence approaches

Category 6? Climate change may cause more hurricanes to rapidly intensify.

The Washington Post’s Joel Achenbach and Ann Gerhart and Capital Weather Gang’s Brian McNoldy contributed to this report.