A coastal storm has taken shape from a non-tropical area of low pressure attached to a dying cold front off the southeastern U.S., bringing heavy rains, coastal flooding, and tropical storm conditions (winds above 38 mph) to the Carolinas today.
So far the heaviest rainfall has fallen from the Grand Strand in South Carolina northward to the Crystal Coast of North Carolina, with radar estimates of totals approaching a foot at the tip of Cape Fear in North Carolina near Bald Head Island.
Another 4 to 8 inches of rainfall is forecast for today across northeast South Carolina and southeast North Carolina, centered on Wilmington, which could produce considerable flash and urban flooding. The flood threat will spread inland across much of North Carolina, including the Carolina Piedmont, through early Tuesday.
Strong and persistent onshore flow will also lead to minor coastal flooding from near Pawleys Island in South Carolina northward to the lower Outer Banks, Hatteras Island, and Pamlico Sound in North Carolina. Seas are already topping 13 feet at offshore buoys this morning and treacherous marine conditions will continue today.
Time quickly running out to become a named storm
The strung-out low-pressure system this morning hasn’t yet separated from the front that spawned it, an important step in it becoming subtropical or even tropical and garnering a name (Helene is the next name on the list). Whether or not it becomes Helene is largely incidental, as the system will be moving inland soon with little additional time to strengthen even if it transitioned to a subtropical or tropical storm.
Although not structurally a tropical storm, the coastal storm is accompanied by tropical storm winds (winds above 38 mph). A buoy 30 miles east of Wrightsville Beach was gusting to 54 mph Monday morning while another nearby buoy at Frying Pan Shoals was reporting 1-minute sustained winds of up to 47 mph. Meanwhile on shore, Wrightsville Beach was gusting above 40 mph by early Monday.
The low-pressure center is forecast to move over land later Monday afternoon south of Myrtle Beach, though inclement weather will be mostly north of where the center comes ashore. Conditions should improve noticeably on Tuesday from southeast to northwest across North Carolina, with lower rainfall totals spreading into southern Virginia.
Gordon weak and no threat to land
Gordon weakened to a Tropical Depression over the weekend, succumbing to the struggles which have plagued the deep Atlantic this season.
Gordon has its work cut out, as dry air is expected to be an impediment for most of the week. The forecast restrengthens Gordon back into a low-end tropical storm but the system is expected to bend northward and poses no threat to land.
Watching the western Caribbean next week
Longer-range forecast models are hinting at storminess building over the western Caribbean for early next week.
It’s too soon to talk specifics, but this is likely courtesy of the Central American Gyre, a sprawling low-pressure area extending from the eastern Pacific across Central America into the Caribbean. The Central American Gyre or CAG is a known breeding ground for tropical systems in late September and October.
We’ll discuss this more as the forecast becomes clearer in the days ahead, but South Florida will need to monitor the unsettled weather as whatever comes of it could get drawn northward later next week. We still have plenty of time to see how it all shakes out.