Ophelia Could Become Hurricane Before Lashing East Coast

From a Washington Post story by Matthew Cappucci headlined “Ophelia strengthens and could become hurricane before lashing East Coast”:

Tropical Storm Ophelia formed Friday afternoon and quickly strengthened close to hurricane strength. The strong tropical storm is set to drench the East Coast this weekend, bringing heavy rain in addition to strong gusty winds, rough surf and coastal flooding, the National Hurricane Center reported. Tropical storm warnings are in effect from Cape Fear, N.C., to the Delaware-Maryland border on the Delmarva Peninsula, with storm surge warnings blanketing a similar area.

Because of the storm’s “unexpected strengthening” Friday, a hurricane watch was added for the zone from Surf City to Ocracoke Inlet along the North Carolina coast, the Hurricane Center wrote at 5 p.m. Friday. The storm is forecast to remain a 70 mph tropical storm when it makes landfall Saturday morning in the eastern part of the state, but winds would only need to increase 4 mph for Ophelia to be considered a hurricane which the Hurricane Center said “cannot be ruled out.”

As the storm comes ashore, some coastal zones could see 3 to 4 feet of storm surge, sparking concerns for significant shoreline inundation that the Hurricane Center warns could be “life-threatening.” Major coastal flooding is forecast in the Virginia Beach area, with areas of minor to moderate flooding predicted along the North Carolina Outer Banks, Chesapeake Bay and Tidal Potomac River, Delmarva Peninsula and New Jersey Shore.

In Virginia, Gov. Glenn Youngkin (R) declared a state of emergency to activate its emergency support team.

“We want to ensure that all communities, particularly those with the greatest anticipated impact, have the resources they need to respond and recover from the effects of this storm,” Youngkin said.

Up to half a foot of rainfall is anticipated in portions of Virginia, North Carolina and the Delmarva Peninsula. That could lead to freshwater flooding inland, especially in places also facing onshore winds and a storm surge. That will back up rivers, preventing drainage to the sea. Three or more inches of rain could also spread into parts of extreme southern New England.

Ophelia is the 16th named storm of the 2023 Atlantic hurricane season. Experts called for a busier-than-average season thanks to record-warm waters across the majority of the Atlantic.

If the season ended Friday, it would still go down in the books as more active than normal, but it is barely halfway done. And with the focus historically shifting to “homegrown” storms during the back half of the season, it’s far too soon to let one’s guard down.

As of 5 p.m. Friday, the center of the storm was 165 miles south-southwest of Cape Hatteras. It had maximum sustained winds of 70 mph at its core — just 4 mph from hurricane strength — as it headed north-northwest at 13 mph.
The storm earned a named as it transitioned from a mid-latitude storm, formed from a wave of low pressure on a front, into a tropical system, drawing energy from the warm waters of the Gulf Stream.

After making landfall Saturday morning, Ophelia is forecast to sweep up the Chesapeake Bay and gradually weaken.

Strong winds likely

Nontropical zones of low pressure are usually bigger than a purely tropical system. That means they spread their winds across a bigger area. Even as a tropical storm, Ophelia will have a very large wind field, given its nontropical origins.

From North Carolina to New Jersey along and east of Interstate 95, gusts of 40 to 50 mph are possible inland, with gusts of 50 to 60 mph at the coastline. A few gusts of 70 mph are possible closer to where the center comes ashore in North Carolina.

These strong winds could cause some downed trees and power outages, especially because heavy rain will loosen soils, and tree roots will become less anchored to the ground.

North of the storm’s center, winds from the east will also pile water against the coastline, causing a significant tidal surge, or rise in ocean water above normally dry land in coastal areas.

Significant coastal flooding possible

In Southeast Virginia and along the Delmarva coast, moderate to major coastal flooding and a 3- to 4-foot storm surge is expected. At Bowers Beach on the Murderkill River, the forecast is for flood stage to reach 8.7 feet, which would narrowly eclipse the record. Seven tidal gauges are forecast to be in major flood stage, and 20 others will reach moderate flood stage.

Particularly vulnerable are the Outer Banks of the Carolinas. A 3- to 5-foot surge is possible along the Pamlico and Pungo rivers, as well as on the Neuse and Bay rivers. Serious inundation is possible for Pamlico and Albemarle sounds.

In the Chesapeake Bay, a general 2 to 4 feet of surge is possible with the Saturday high tide.

Heavy rains and freshwater flooding

Flooding won’t be an issue just at the coastline. The waterlogged storm system will dump a month or more worth of rainfall in spots. Multiple weather models paint a jackpot of 6 inches or more of rain near Virginia Beach. It’s likely that the heaviest rain bands will precede the center of the storm and should begin spiraling ashore in the Carolinas on Friday afternoon.

Rainfall totals of 2 to 4 inches will be common from central North Carolina, Virginia and Pennsylvania northeastward into southern New England. Extreme northeastern North Carolina, the Virginia Tidewater and the southern Delmarva Peninsula are forecast to pick up 4 to 6 inches. Some localized flooding is possible.

Tornado risk

A couple tornadoes can’t be ruled out in eastern North Carolina, especially along the Outer Banks, and in Southeastern Virginia and Southern Maryland. That’s where Ophelia will swirl a narrow tongue of warm, humid air ashore, which will allow a few thunderstorms to blossom. Those thunderstorms will likely rotate as they grow vertically into a “sheared” atmosphere, or one characterized by a change of wind speed and/or direction with height. A sporadic tornado or two is possible, especially from 4 a.m. Saturday onward in northeastern North Carolina.

Matthew Cappucci is a meteorologist for Capital Weather Gang. He earned a B.A. in atmospheric sciences from Harvard University in 2019, and has contributed to The Washington Post since he was 18. He is an avid storm chaser and adventurer, and covers all types of weather, climate science, and astronomy.

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