Flash Flood — Yancey, North Carolina

2024-09-26 to 2024-09-27 · near Lunday, Yancey, North Carolina

Event narrative

Historic, catastrophic flash flooding developed along the Cane River and South Toe River basins during the overnight and early morning hours of the 27th as rainfall rates began to intensify again during the evening of the 26th. The most intense rainfall occurred just after sunrise, as the tropical rain bands near the center of Helene swept across the area. These rivers and their tributaries inundated hundreds of homes, with some structures being completely destroyed. Numerous roads were damaged or destroyed. More than 200 landslides were reported in this part of Yancy County, further contributing to the damage and destruction. Multiple fatalities were reported, mostly within homes that were swept away, although one death occurred in a vehicle, and another may have occurred in a landslide. Storm total rainfall was 8-14 inches across most of the county. However, amounts across the southern part of the county, including the headwaters of the Cane and South Toe Rivers, were mainly between 15 and 22 inches. The maximum storm total rainfall in North Carolina associated with Helene and the predecessor rainfall event occurred at Busick, where just over 30 inches fell.

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 → (35.9500, -82.1960)

Source: NOAA Storm Events Database, event_id 1218187. Narrative written by the NWS forecast office that issued the report.