Creating High-Resolution Hail Datasets Using Social Media and Post-Storm Ground Surveys

Hail reports from Storm Data typically produce insufficient spatial and temporal resolution to determine the true hail-fall character of a storm. However, high-resolution hail databases are essential for meaningful hail studies utilizing radar base products and for the development and refinement of hail algorithms. Today, many broadcast and print media outlets provide supplemental social media forums where the public, armed with a wide array of digital cameras and mobile devices with photo and application software capabilities, can submit reports of severe weather. These technologies and social media web sites have the potential to serve as a substantial resource for additional meteorological observations. To illustrate the utility of reports from social media and post-storm ground surveys, hail information was gathered and analyzed from a notable hail event that occurred across the Wichita, Kansas, metropolitan area on 15 September 2010. A total of 464 hail size data points were obtained within a ~ 648 km² (250 mi²) area, with 94% of the reports originating from social media and the hail survey. Additionally, social media and the post-storm ground survey identified eight hailstones that exceeded the diameter of the previous state record, with the largest diameter measured at 19.7 cm (7.75 in.). The reconstruction of the hail-fall character obtained from this dataset is among some of the highest spatial resolution hail datasets available to date, and has the additional benefit of photographic documentation for approximately 93% of the hail data points in the study.