Natural gas distribution companies and electric utilities ramped up their preparedness efforts as the path of Hurricane Florence, a Category 3 storm as of 2 p.m. ET Wednesday, took a notable shift and was set to approach the coast of North Carolina or the northern coast of South Carolina beginning Thursday.

The National Hurricane Center (NHC) said Florence was moving toward the northwest near 15 mph. On the forecast track, the center was expected to move between Bermuda and the Bahamas, approaching the coast of North or South Carolina on Thursday and Friday, then meander near the coastline through Saturday. Maximum sustained winds dropped slightly Wednesday afternoon to 125 mph with higher gusts, falling back from its Category 4 to a Category 3, but Florence remained on track to be an extremely dangerous major hurricane when it nears the U.S. coast.

Industry Preparing For Aftermath

Work that started earlier in the week to prepare two major natural gas pipeline projects in the path of the storm continued on Wednesday. Construction on the Mountain Valley Pipeline (MVP) was suspended in anticipation of inclement weather and crews were working to stabilize the right-of-way, secure pipe in open trenches and take other precautionary steps along the 300-mile route in West Virginia and Virginia.

Despite new projections that the storm is likely to pause over North Carolina and move southward, MVP spokesperson Natalie Cox said all efforts remain focused on preparation.

The similarly routed Atlantic Coast Pipeline (ACP) project, with a path originating in West Virginia, passing through Virginia and into North Carolina, is also girding for Florence’s effects. Although construction along the 600-mile route was suspended last month over regulatory issues, crews and contractors will be on standby throughout the storm, spokesperson Aaron Ruby said.

“We’re expecting heavy rainfalls across the ACP footprint, so we’re taking all necessary precautions to prepare for the storm,” he said. “We’re reinforcing environmental controls and stabilization measures at our worksites, and we will continue monitoring them closely throughout the week.”

States of emergency have been declared in both Virginia and North Carolina, while West Virginia authorities have made a similar declaration. The Virginia Department of Environmental Quality (DEQ), for instance, has been in “close communications” with both projects, along with its erosion and sediment control contractors, emergency response staff and federal regulators, agency spokesperson Ann Regn told NGI.

“Staff will be on site as long as it’s safe, and back out there as soon as the storm passes,” she said of DEQ’s efforts to oversee the companies storm response work.

Utilities also continued to prepare. Piedmont Natural Gas, a subsidiary of Duke Energy, said it had activated its Severe Weather Preparedness Plan ahead of Florence, which includes ensuring the availability of additional communication links and resources, adequately fueled vehicles for use by personnel in impacted areas, appropriate equipment in the potential impact areas and preparation of facilities for potentially high winds and flood conditions.

“The safety of our customers and our communities remains top priority for Piedmont Natural Gas as Hurricane Florence approaches the Carolinas,” said Piedmont Executive Vice President Frank Yoho, who also is president of Duke’s natural gas business.

Duke also owns six nuclear generation facilities in the Carolinas that together produce nearly 11,000 MW of electricity. The Charlotte, NC-based company was “staffing up” ahead of the storm, and workers were checking the readiness of equipment and back-up equipment at the nuclear sites, according to spokeswoman Mary Katherine Green.

While the nuclear facilities are designed to withstand significant winds and rain, the company will shut down each plant on a case-by-case basis before sustained inland winds are greater than 73 mph, Green told NGI. In the event of a shutdown, Duke will decide when to restart the facilities following the storm based on the damage sustained to area transmission lines. “We can’t put power out on the grid if there’s no one to send it to.”

Energy Ventures Analysis Inc. senior analyst June Yu said only Florida Power & Light Co.’s Turkey Point nuclear facility shut down ahead of 2017’s Hurricane Irma, which hit the Florida Keys as a Category 4 storm. The two-unit, 1,600-MW plant remained shut for five days.

Virginia Natural Gas, one of four natural gas distribution companies of Southern Company Gas, also was closely monitoring the progress of Florence and on Wednesday was implementing its emergency response plan.

Demand Destruction Likely

Matthew, a Category 1 hurricane, was the last major hurricane to hit the region in 2016. It pushed natural gas demand down about 2% (roughly 1 Bcf/d) below pre-storm levels, according to Genscape Inc. Irma, which hit Florida at about this same time last year, sent power demand in the Southeast down by around 2.5 Bcf/d from peak to trough (mostly in Florida), and total demand destruction in the power sector from Irma was about 10 Bcf over a seven-day period.

On Sept. 11, 2017, 6.1 million customers in Florida, 59% of the state, had lost power. This number fell to 2.6 million by Sept. 15 and to 0.2 million (2%) by Sept. 20, according to Genscape.

“At this point, we would expect demand destruction from Florence to be a bit less than that of Irma, as Florida has a larger population and a more gas-intensive power stack than the Carolinas,” Genscape natural gas analyst Eric Fell said.

Heavy Rainfall, Flooding Likely

Florence is expected to produce heavy and excessive rainfall, with coastal North Carolina expected to see 20-30 inches and in some isolated places, up to 40 inches. “This rainfall would produce catastrophic flash flooding and significant river flooding,” the NHC said.

South Carolina, western and northern North Carolina are expected to receive five to 10 inches and in isolated areas up to 20 inches. Elsewhere in the Appalachian and Mid-Atlantic states, three to six inches of rain are expected, with up to 12 inches in isolated areas, according to the NHC.

“That heavy rain threat may last for days into early next week in some areas, given Florence’s slow movement. Disastrous flooding is expected in some areas, not simply near the coastal Carolinas where the heaviest rain totals are forecast, but also in the Appalachians, where heavy rain over mountainous terrain is likely to trigger mud and rockslides,” meteorologists said.

“A storm with the track of Florence is unprecedented. It was located farther north in the Atlantic than any other storm to ever hit the Carolinas, so what we’re forecasting is unprecedented,” said AccuWeather’s Marshall Moss, vice president of forecasting and graphics operations. “Also, most storms coming into the Carolinas tend to move northward, and this storm looks like it’s going to stall over the region and potentially bring tremendous, life-threatening flooding,”

Radiant Solutions said recent model guidance showed Florence was expected to stall off the coast of North Carolina and drift southwestward parallel to the coast before tracking inland into South Carolina. This change has major implications on the storm’s impact, as a stalled hurricane would bring a prolonged period of hurricane force winds and pounding surf to the coastline along with extremely heavy rain with widespread amounts of 10-20 inches and localized amounts upwards of 40 inches possible, the weather forecaster said.

“Changes in the storm’s track have reduced the threat of inland flooding in the Mid-Atlantic at the expense of a heightened threat of more prolific flooding from both storm surge inundation and extreme rainfall for areas closer to the coasts of North and South Carolina,” Radiant senior meteorologist Steve Silver said. “In addition, the storm’s slow track will promote a prolonged period of hurricane force and tropical storm force winds, maintaining a high probability of widespread power outages for areas in Florence’s path.”

Given the unusual jet stream pattern responsible for Florence’s expected erratic path, further changes to the storm’s track and ensuing impacts are possible in the coming days, he said.

“That heavy rain threat may last for days into early next week in some areas, given Florence’s slow movement. Disastrous flooding is expected in some areas, not simply near the coastal Carolinas where the heaviest rain totals are forecast, but also in the Appalachians, where heavy rain over mountainous terrain is likely to trigger mud and rockslides,” meteorologists said.