ELSS: Electrification and Lightning of Severe Storms (aka TELEX-1)

Summary

The broad objective of TELEX is to learn how lightning and other electrical storm properties are dependent on storm structure, updrafts, and precipitation. This information will point to new ways for the National Weather Service to use lightning observations to improve forecasts and warnings of hazardous weather.

TELEX took advantage of new sensors now used routinely by NSSL. One is the KOUN radar in Norman, a WSR-88D radar modified with polarimetric parameters to provide information about the particle size and water phase of precipitation. The other new sensor is the Oklahoma Lightning Mapping Array (LMA). The OK-LMA is a network of ten stations in central Oklahoma that continuously maps the structure of all types of lightning in three-dimensions out to a range of 75 km and in two-dimensions out to a range of 200 km.

To these two systems, the TELEX team added balloon soundings to measure the electric field profile of storms. An electric field profile can provide scientists information about how a storm becomes electrified and about the forces responsible for lightning. This effort, funded partly by the National Science Foundation (NSF grant ATM-0233268), was the maiden field program for NSSL's new mobile laboratory, used to collect the balloon data. The electric field sensor was custom-built by NSSL with assistance from OU, New Mexico Institute of Mining and Technology, and NCAR. Temperature, pressure, and humidity were measured by an NCAR system that also provided GPS tracking of the balloon.

The TELEX team succeeded in flying fourteen balloons into nine storms on seven missions. Two of these storms were mesoscale convective systems, a specific target of TELEX. NSSL scientists are now analyzing the processed data to address the project's objectives.