Observational Capabilities of the FRONT Network: 21 May 2014 Case

This project demonstrates the observational capabilities of the Front Range Observational Network Testbed (FRONT) network, located in northeastern Colorado, to thunderstorm research. The FRONT network initially began collecting data early in 2014, after the NCAR S-Pol radar moved to its new location near Firestone, CO. Initial thunderstorm observation opportunities using FRONT occurred during the 2014 convective season. From 20 May – 20 June 2014, FRONT data collection was done in support of North Carolina State University Prof. Sandra Yuter's Radar Observations of Storms for Education (ROSE) project. The current work, the result of a Research Experience for Undergraduates (REU) project, is based on the FRONT data collected during the 21 May 2014 supercell thunderstorm event. The radar analyses utilize data from the CSU-CHILL radar in Greeley, CO, the NCAR S-Pol radar near Firestone, CO, and the NWS KFTG NEXRAD radar in Denver, CO. The pre-storm environment is analyzed using precipitable water vapor data collected via SuomiNet and NWS soundings. Multiple Doppler wind field syntheses involving various combinations of both two and three radars were done key points in the storm's lifetime. Regions where electrical charging of hydrometeors was probably active were identified using results from a hydrometeor classification scheme which marked regions where significant graupel concentrations were found within updrafts. Data from the northern Colorado Lightning Mapping Array (LMA) and from the National Lightning Detection Network (NLDN) was used to document the storm's electrical characteristics. These combined FRONT data sets were used to analyze the three-dimensional evolution of the storm over a three-hour period. Particularly, an interrogation was made of the lightning hole corresponding to a bounded weak echo region (BWER) associated with the main storm updraft.