May 21, 2020
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
Source: NOAA National Weather Service Storm Events Database (event 892085). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Grayson County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.