Heavy Rain in Galax (c) County, Virginia

The COOP station at the Galax Water Plant (GAAV2) measured 5.50 inches for the 24 hours ending at 700 AM local time on the 9th, although most of the rain fell in just a few hours. This was the highest measured daily rainfall at this station since records began at this site in 2000, and the 6th highest daily since data collection began at any COOP station in Galax in 1955. The 5.50 inches in 24-hour value falls into the 90 percent confidence interval (5.33-6.50 inches) for a 50-year average recurrence interval (.02 annual exceedance probability) per NOAA Atlas 2.

Convective coverage was more widespread on the afternoon of the 8th and into the early morning of the 9th in association with a slow-moving frontal boundary and very high moisture. The most notable storms occurred over Galax City and nearby parts of western Carroll County during the late evening hours. Radar estimated 4 to 6 inches fell in several hours across parts of Galax with more than 6 inches in the Pipers Gap area of western Carroll County. The top five gage reports ending 12z on the 9th included Pipers Gap IFLOWS (PPGV2) 5.57', Galax Water Plant COOP (GAAV2) 5.50', and Woodlawn IFLOWS (WDLV2) 5.12'. At the Pipers Gap gage, 2.44' fell in 1-hour during the most intense portion of the storms, roughly a 25-year (.04 AEP) recurrence interval.