A low pressure system brewing hundreds of miles east of Florida’s peninsula was gathering strength Thursday, while Hurricane Nigel rapidly spun northeastward with no threat to the Lowcountry.
The new system moved toward the north at 9 mph and whirred about 370 miles from Charleston on Thursday morning, as it dumped disorganized showers and thunderstorms, according to the National Hurricane Center. Its maximum winds speeds were about 35 mph, with higher gusts.
Within two hours Thursday morning, the system’s chance of formation within the next 48 hours jumped from 40% to 60%. Meteorologists called the system a “potential tropical storm,” as of noon Thursday.
Forecasters expect it will form into a non-tropical low pressure storm by early Friday. Later Friday or Saturday, the storm will push north bringing gusty to gale-force winds, heavy rain and high surf to South Carolina’s coast.
However, forecasters predict the majority of impact would be seen along the North Carolina coast. In an 11 a.m. NHC advisory for the system, it noted a tropical storm warning and storm surge watch had been triggered for parts of North Carolina.
“Winds will become strong, especially Friday and Friday night over land areas, with gusts perhaps reaching as high as 30 or 35 mph, highest near the coast,” the National Weather Service’s Charleston Office said Thursday.
A low pressure system is an area of a relative pressure minimum that has converging winds and rotates in the same direction as the earth — counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere, the NHC explained.
The NWS’ Charleston Office said coastal flooding and high surf will be a concern as the system moves through, with the biggest impacts on Friday. It could require coastal flood and high surf advisories. Gale watches and warnings could also be necessary for “at least parts” of the marine area Friday into Saturday, the office said.
“Whether it’s a non-tropical gale or a tropical storm, it will affect SC,” Frank Strait, the state’s severe weather liaison, said.
Beyond the churning system near Florida, a second system, in the eastern tropical Atlantic, is stirring.
A tropical wave located west of the Cabo Verde Islands has environmental conditions that look as though it could form into a tropical depression late this week as it moves westward across the eastern and central tropical Atlantic between 10 and 15 mph, according to the National Weather Service’s Charleston Office.
The chance of formation within the next week is 70%.