Flash Flood — Catawba, North Carolina

2024-09-27 to 2024-09-28 · near Catawba, Catawba, North Carolina

Event narrative

A stream gauge on the Catawba River at Lookout Shoals Dam indicated flash flooding developed in the vicinity of the damn after widespread extremely heavy rainfall occurred in the upper part of the basin across the mountains and foothills over three days, with 6-9 inches falling across Catawba County. More than 100 structures were damaged on the Catawba County side of the river, especially in the Carpenters Cover community. Numerous roads were inundated and damaged as well. The gauge at Lookout Shoals reached its highest level since August 1940.

Wider weather episode

Tropical Cyclone Helene began organizing over the western Caribbean on the 23rd and 24th of September before rapidly intensifying as it moved north through the eastern Gulf of Mexico on the 25th and 26th. A plume of moisture extending from the intensifying storm interacted with a slow-moving cold front to produce a band of widespread heavy rain showers and embedded scattered thunderstorms over the southern Appalachians and vicinity on the 25th and 26th, resulting in a predecessor heavy rainfall and flash flooding event over these areas. Helene made landfall in the Florida Big Bend and moved quickly N/NE through Georgia before turning toward the N/NW once the remnant center reached northeast Georgia. Tropical rainbands around the center of Helene swept over areas with already-saturated soils over the mountains and foothills during the early morning of the 27th, resulting in extreme rainfall and record, catastrophic flash flooding across multiple basins with headwaters near the Blue Ridge escarpment. Due to its quick movement, Helene was still a strong tropical storm when the wind field reached the western Carolinas and northeast Georgia. Frequent wind gusts of 55 to 70 mph, with occasional gusts of 80 mph...and likely as high as 100 mph across the higher elevations combined with saturated soils to produce widespread damage to trees and electrical infrastructure. Across the mountains, some east and southeast-facing slopes above 3000 feet saw canopy-loss of 80% or more. Hundreds of trees fell on houses, vehicles, and power lines throughout the area, resulting in several fatalities. Almost all customers in several counties lost power for at least a brief period. Most people were without power for at least a couple of days, while thousands were without power for a week or more.

View location on OpenStreetMap → (35.7740, -81.1130)

Source: NOAA Storm Events Database, event_id 1218212. Narrative written by the NWS forecast office that issued the report.