Flash Flood in Yadkin County, North Carolina

A radar-estimated 3.5 to 4 inches of rain fell across portions of northern Yadkin County within a 3-hour period. Rainfall rates in the strongest cells ranged anywhere from three to locally five inches per hour. Runoff from the rainfall caused flooding across multiple roads along Highway 67 between the communities of East Bend and Jonesville. In the area surrounding the community of East Bend, Chestnut Street was flooded and impassible due to heavy runoff. Logan Creek was observed flooding out of its banks across Mill Hill Road, causing serious damage to the road that required repairs. Genie Road was also flooded from Logan Creek. Further west, Highway 601 was flooded and impassible near the community of Booneville.

An upper level trough passed across the central Appalachians during the afternoon and evening of May 18th, triggering widely scattered showers and thunderstorms to the north of a stationary front stretching across northern North Carolina. Upper level winds ahead of the trough were light. Moisture was abundant, with precipitable water values ranging from 1.2 to 1.3 inches across northwest North Carolina, while surface dewpoint temperatures were observed in the mid to upper 60s. Mixed Layer CAPE (Convective Available Potential Energy) values observed during the afternoon and evening were in excess of 1,000 J/Kg. The thunderstorms that developed during the afternoon and evening were localized but extremely efficient at producing rainfall, with rates within several storms exceeding four inches per hour. They were also slow-moving, allowing the storms to remain over locations for extended periods of time.