A Climatology Study of Supercell Environments Near the Black Hills

Author: Joseph Kragness, Department of Atmospheric and Environmental Sciences

Mentor: Dr. Adam French, Department of Atmospheric and Environmental Sciences

Of the different types of severe storms, supercells are among the most dangerous. These large, rotating thunderstorms commonly leave damage paths caused by large hail, strong winds, and occasional tornadoes. With the goal of increasing the understanding of supercells and their environments near isolated terrain features, a climatology of supercell days around the Black Hills is being conducted. Potential supercell events were identified using archived National Weather Service hail and tornado reports that occurred between 2000 – 2018 and within 100 miles of Rapid City, South Dakota. The reports were separated into two categories: reports 100 miles to the East and 50 miles to the West of Rapid City. These two categories will allow for the separate analysis of cases that were and weren’t directly affected by the Black Hills. For each case, radar data will be used to determine the presence or absence of a supercell. On days where there was a confirmed supercell, archived surface meteorological data and atmospheric soundings of wind, temperature and moisture will be collected to quantify environmental conditions. These environmental conditions will then be compared with those near supercells not influenced by terrain. It is anticipated that the Black Hills may locally alter the environment to create conditions favorable for supercells in otherwise less-favorable environments.