STEPS
(Severe Thunderstorm Electrification and Precipitation Study)
The main components of STEPS include (1) precipitation process studies, (2)
storm electrification studies, and (3) hydrometeor identification studies, in High
Plains convective storms. The main focus is on severe storms producing
predominantly positive cloud-to-ground lightning, but there is interest in these
processes in all convective storms, with an aim towards improving the
understanding of the interrelationships between precipitation processes and
electrification in this spectrum of storms. The STEPS field season ran from 22
May through 9 July, 2000, during which almost two dozen field coordinated
observing operations were conducted in northeastern Colorado and northwestern
Kansas. Observations were obtained using multiple Doppler and multiparameter
radars, a lightning discharge mapping system, instrumented aircraft and
balloons, and a mobile mesonet comprised of instrumented cars, all in
conjunction with standard operational observations by the National Weather
Service and the National Lightning Detection Network.
The only aircraft involved in STEPS was the armored T-28, operated by the
South Dakota School of Mines and Technology (SDSMT) under a cooperative
agreement with the National Science Foundation. Summarized here are the
observations obtained during more than a dozen research flights in support of
the STEPS field program.
![Photo of a target thunderstorm](/repository/t28/STEPS/Image36.jpg)
Figure 1: Picture of a target storm during STEPS Project.
The microphysical and electrical observations from T-28
instrumentation and polarimetric radar data are used to study the physical
relationships between precipitation development and electrification and to
compare between hydrometeor classification derived from the polarimetric radar data and the T-28 measurements.
![June 29, 2000 storm photo](/repository/t28/STEPS/Image37.jpg)
Figure 2: Picture of the June 29, 2000, storm taken while T-28 was approaching the storm. Time is in GMT. |