Flash Flood — Alleghany, North Carolina

2024-09-27 · near Laurel Spgs, Alleghany, North Carolina

Event narrative

Runoff from continued heavy rain resulted in numerous roads becoming flooded and impassible across Alleghany County per reports from the public and from the Alleghany County 911 Dispatch Center. Rainfall totals ranging from seven to locally ten inches were observed across much of the county on the 26th, resulting in numerous flooded creeks and roads that were covered by several inches of flowing water. After a brief lull in rainfall as the Predecessor Rainfall Event concluded, allowing flooding to subside briefly, heavy rain associated with the arrival of Tropical Storm Helene moved across the county, falling at rates of one to two inches per hour. Reports include Saddle Mountain Road being washed out and destroyed near its intersection with the Blue Ridge Parkway. Along the New River, the Farmers Fish Camp Road Bridge was completely submerged by the New River, with significant damage observed on the bridge once the flooding receded.

Wider weather episode

Hurricane Helene made landfall in Florida as a powerful Category 4 hurricane late Thursday, September 26, and moved quickly northward into the southeastern states, and then turned slightly northwestward towards the southern Appalachian Mountains overnight into Friday morning, weakening as it moved over land. Helene's intensity and fast forward motion led to impacts being felt well inland, from the Florida Big Bend area into the Appalachians, and there was extensive damage in northwest North Carolina. Widespread cellular service and power outages, some lasting for several days, occurred as high winds downed thousands of trees across the region. While there were widespread wind gusts 50 to 60 MPH, pockets of wind gusts measured 85 to 91 MPH contributed to several swaths of widespread wind damage in the northwest North Carolina mountains. There were three confirmed tornadoes associated with the remnants of Hurricane Helene in nnrthwest North Carolina.

Flooding impacts from Hurricane Helene were extensive across the area, and were exacerbated by a predecessor rainfall event that occurred a few days before Helene reached the region, which brought six to eight inches of rain to the mountains prior to the arrival of the remnants of Helene. The three day rainfall totals associated with the remnants of Hurricane Helene were highest along the mountains of northwest North Carolina, where observations of 20 to 21 inches of rain were recorded. A cooperative observer in Sparta, North Carolina reported over 17 inches of rain over three days. The Piedmont of North Carolina received much less rain, between one and two inches, with a couple areas around three inches.

View location on OpenStreetMap → (36.3775, -81.2367)

Source: NOAA Storm Events Database, event_id 1219130. Narrative written by the NWS forecast office that issued the report.