Flood — Danville (c), Virginia

2020-05-21 to 2020-05-24 · near Danville, Danville (c), Virginia

Event narrative

The Dan River at Danville (DVLV2) exceeded Moderate flood stage of 26 feet, cresting at 27.57 feet early on the morning of May 23rd. This was the 3rd highest stage at the current gaging site after the remains of Hurricane Fran in September 1996 (28.65 ft.) and Hurricane Michael in October, 2018 (30.01 ft.). Flood stage categories on the Dan River were adjusted upward by several feet in May 2019. The peak discharge from this flood of 43,900 cfs was estimated to be slightly in excess of a 10-year flood event (0.10 annual exceedance probability) according to USGS studies. Several roads were closed by flooding in the Danville area.

Wider weather episode

An upper-level low became cut-off over the southern Appalachian region for several days leading to persistent rainfall and eventually some flooding. Four-day (96-hour) rainfall amounts ending at 800 AM EDT on May 22nd ranged from 3 to over 12 inches in the most favored locations. Some of the 11-inch+, 4-day rain totals in Roanoke County were within the 200-year recurrence interval (9.78 to 11.8 inches) per NOAA Atlas 14. The flooding that ensued was almost all in the form of river flooding that took several days to develop. Nearly every major river basin saw some flooding, but the most notable occurred in the New River basin where crests ranged from the 4th to 8th highest on record at the Virginia gaging stations along the river. Stages on the upper New were higher than in October 2018 when the remains of Hurricane Michael transited the region. The incredible rainfall, runoff and numerous debris flows produced widespread damage to roads in the region with VDOT reporting over $5 million in damages.

View location on OpenStreetMap → (36.5958, -79.3884)

Source: NOAA Storm Events Database, event_id 892101. Narrative written by the NWS forecast office that issued the report.