Flood — Giles, Virginia

2024-09-27 to 2024-09-29 · near Glen Lyn, Giles, Virginia

Event narrative

The New River at Glen Lyn (GLLV2) crested at 24.24 feet (180,000 cfs) at 1:00 PM EDT on Sept. 28th (28/1700 UTC) due to heavy rain associated with Tropical Cyclone Helene. It was observed that the gage flatlined at this stage for about 3 hours, so it's possible that the crest was closer to or rose above 22 feet. This is the second highest crest in the history of this gage, behind the flooding event of August 1940 (27.50 ft). This crest rates just below a 100-year Average Recurrence Interval (ARI), or a 1% Annual Exceedance Probability per USGS StreamStats. The flooding was the result of between 10 and locally 20 inches of rain that fell across the upper New River basin between the 25th and 27th, with totals ranging anywhere from between a 200-year and more than a 1,000-year ARI per NOAA Atlas 14 Point Precipitation Frequency estimates. Near the town of Pembroke, substantial flooding of homes and property was observed along Caboose Lane, Overview Drive, and Royal Drive. At the Riverview Campground in the Town of Narrows, 70 to 80 campers were inundated, with several of those declared uninhabitable after the flooding receded. Only a handful of campers in the park were high enough to remain above the flooding. The water treatment plant in Narrows was surrounded by water as well. Backwater flooding from the New River occurred along Wolf Creek, with water entering Anna's Restaurant, as well as multiple businesses across from the Narrows Farmers Market. Near the community of Rich Creek, several campers at Gentry's Landing Campsite were inundated, with only a few campers on the highest parts of the property unaffected by flooding. Overall, the county assisted 48 families with relocation in the wake of the storm. At least 200 tons of debris had to be removed from along the banks of the New River.

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, almost only 12 hours after landfall, and there was extensive damage in southwest Virginia. Widespread cellular service and power outages, some lasting for several days, occurred as high winds downed thousands of trees across the region. Winds gusted as high as 55 mph to 65 mph in southwest Virginia. There were three confirmed tornadoes associated with the remnants of Hurricane Helene in the Piedmont of Virginia. Flooding impacts from Hurricane Helene were extensive across the area, and were exacerbated by a predecessor rainfall event that occurred a day 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 Grayson and Smyth Counties, where observations of 10 to locally 15 inches of rain were recorded. The Piedmont of Virginia received much less rain, between one and two inches, with a couple areas around three inches. Total economic losses for Virginia, which include Virginia's agriculture, forestry, and other industries, are expected to range between $416 million and $630 million per an economic analysis released by Virginia Tech researchers.

View location on OpenStreetMap → (37.3835, -80.8834)

Source: NOAA Storm Events Database, event_id 1225983. Narrative written by the NWS forecast office that issued the report.