Kristin M. Kuhlman

TELEX The Thunderstorm Electrification and Lightning Experiment

Measurements during TELEX by a lightning mapping array, polarimetric and mobile Doppler radars, and balloon-borne electric-field meters and radiosondes show how lightning and other electrical properties depend on storm structure, updrafts, and precipitation formation.

Numerically Simulated Electrification and Lightning of the 29 June 2000 STEPS Supercell Storm

Abstract A three-dimensional dynamic cloud model incorporating airflow dynamics, microphysics, and thunderstorm electrification mechanisms is used to simulate the first 3 h of the 29 June 2000 supercell from the Severe Thunderstorm Electrification and Precipitation Study (STEPS). The 29 June storm produced large flash rates, predominately positive cloud-to-ground lightning, large hail, and an F1 tornado. Four different simulations of the storm are made, each one using a different noninductive (NI) charging parameterization. The charge structure, and thus lightning polarity, of the simulated storm is sensitive to the treatment of cloud water dependence in the different NI charging schemes. The results from the simulations are compared with observations from STEPS, including balloon-borne electric field meter soundings and flash locations from the Lightning Mapping Array. For two of the parameterizations, the observed “inverted” tripolar charge structure is well approximated by the model. The polarity of th...

Polarimetric and Electrical Characteristics of a Lightning Ring in a Supercell Storm

Abstract On 30 May 2004, a supercell storm was sampled by a suite of instrumentation that had been deployed as part of the Thunderstorm Electrification and Lightning Experiment (TELEX). The instrumentation included the Oklahoma Lightning Mapping Array (OK-LMA), the National Severe Storms Laboratory S-band Weather Surveillance Radar-1988 Doppler (WSR-88D) polarimetric radar at Norman, Oklahoma, and two mobile C-band, Shared Mobile Atmospheric Research and Teaching Radars (SMART-R). Combined, datasets collected by these instruments provided a unique opportunity to investigate the possible relationships among the supercell’s kinematic, microphysical, and electrical characteristics. This study focuses on the evolution of a ring of lightning activity that formed near the main updraft at approximately 0012 UTC, matured near 0039 UTC, and collapsed near 0050 UTC. During this time period, an F2-intensity tornado occurred near the lightning-ring region. Lightning density contours computed over 1-km layers are over...

A Comparison Between WarnGen System and Probabilistic Hazard Information System for Severe Weather Forecasting

To increase the nation’s preparedness for severe weather, it is important to design effective ways to communicate severe weather information. This study reports an experiment conducted in the 2014 Hazardous Weather Testbed (HWT) comparing the deterministic severe weather warning system WarnGen, and a prototype Probabilistic Hazard Information (PHI) system. Six National Weather Service (NWS) forecasters used both systems to forecast severe hail events. With minimal training, the PHI system received similar levels of system usability and weather situation awareness rating as the WarnGen system. Meanwhile, the PHI system resulted in significantly less temporal stress for the forecaster and all forecasters preferred the prototype PHI system to the WarnGen system. Forecasters believed the PHI system allowed them to convey richer and better weather information to the public, which could result in better service overall.