Flash Flood — Henderson, North Carolina

2024-09-26 to 2024-09-27 · near Bat Cave, Henderson, North Carolina

Event narrative

Historic and catastrophic flash flooding developed along multiple streams across Henderson County during the overnight and early morning hours as rainfall rates began to intensify again during the evening. Flash flooding first redeveloped along the Rocky Broad River in the Bat Cave community, but spread to encompass most of the other major streams in the county, including Mud Creek and Bat Fork in the Hendersonville area, as well as Mills River and Cane Creek. The most intense rainfall occurred around sunrise, as the tropical rain bands near the center of Helene swept across the area. Catastrophic flash flooding first developed along the Rocky Broad River and its tributary Reedypatch Creek. Numerous homes were swept away along both streams. Seven fatalities were reported in Henderson County, mostly occurring in homes that were destroyed in the Bat Cave area (F63HOU, F89HOU, M65UNK, M66HOU, F60HOU, F50HOU, M72UNK). Major flooding developed along Mud Creek and Bat Fork, with numerous businesses and other structures inundated in the Hendersonville area. Meanwhile, stream levels on the French Broad River at Fletcher, which was already in moderate flood, began to increase rapidly around sunrise, reaching major flood stage and exceeding the record stage by more than 10 feet (the gauge was installed in 2002). Numerous roads were damaged or washed out throughout the county. Three-day rainfall amounts ranged from 9-15 inches across much of the county to 15-20 inches, with locally higher amounts across the southern and eastern part of the county. Hundreds of landslides also occurred across Henderson County, especially in the eastern part of the county. This contributed further to structural damage.

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 → (35.4660, -82.2740)

Source: NOAA Storm Events Database, event_id 1218184. Narrative written by the NWS forecast office that issued the report.