Heavy Rain in Craig County, Virginia

The COOP station at New Castle (NWCV2) had a 2-day rainfall total of 4.77 inches ending at 700 AM EST on the 22nd which was a record for the month of May and 9th highest for any 2-day period. For the 3-day period ending the same day, the station recorded 6.12 inches, the highest ever for May and 4th highest for any 3-day period. The 3-day total was in 90 confidence interval (5.65-6.63 inches) for a 25-year rainfall event (.04 annual chance of occurrence). Extensive road damage was reported by VDOT in the County.

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.