PROJECT ALERT NOTICE (NC) Response to high runoff following passage of "Potential Tropical Cyclone Eight"

Date: Tue, 17 Sep 2024 22:06:37 EDT

Summary: Moderate to extreme high rainfall totals occurred following the passage of Potential Tropical Cyclone Eight across parts of coastal and inland North Carolina and South Carolina on September 15-17, 2024.

A potential tropical cyclone #8 developed off the coasts of North Carolina and South Carolina in mid-September 2024. Although the storm did not evolve into a full-scale tropical storm or hurricane, its movement across coastal and inland parts of North Carolina and South Carolina on September 15-17 resulted in a wide range of moderate to extreme high rainfall amounts.

The National Weather Service Office in Wilmington, NC, reported rainfall totals exceeding 10 inches across parts of New Hanover and Brunswick Counties (reference: https://www.weather.gov/ilm/2024PTC8). Extreme high rainfall totals exceeding 19 inches were reported for Southport and Carolina Beach, resulting in historic flooding levels in these areas.

Elsewhere across North Carolina, rainfall totals for this event were commonly in the range of 2 to 5+ inches, with the higher amounts of this range across the Coastal Plain and eastern Piedmont regions. Rainfall totals in the range of 2 to 3+ inches were widespread across the western and central Piedmont regions.

USGS field crews from the Raleigh Field Office (5 crews of 2 technicians) and the Charlotte Field Office (also 5 crews of 2 technicians) responded by obtaining high-flow measurements at sites in their respective field regions. Most of the measurements were in the medium and "medium +" ranges that helped with ratings development and maintenance, particularly at some of the newer sites in Fayetteville.

As of the evening of the 17th, a total of 4 streamgages across eastern North Carolina were reported to be above flood stage and still rising: (1) 02087500 Neuse River Clayton, (2) 02087570 Neuse River Smithfield, (3) 02103000 New River Gum Branch, and (4) 02105500 Cape Fear River W.O. Huske Lock Tarheel (reference: https://waterwatch.usgs.gov/?m=flood&r=nc&w=map).

No reports of downed or damaged streamgages were received as of this project alert.

All field personnel are known to be safe and accounted for at this time.

No other project alert is planned for this event.