MMM SEMINAR NCAR
Radar and Lightning Observations from
STEPS
The Severe Thunderstorm Electrification and
Precipitation Study
(STEPS) was established to improve our understanding
of
electrification mechanisms and lightning in High Plains storms. In
particular, STEPS focused on investigating anomalous positive cloud-
to-ground (CG) lightning, which had been documented to occur more
often in this region than in the rest of the
lightning observations of four storms observed during the STEPS field
campaign will be discussed. The four cases include two predominantly
positive CG-producing (PPCG) storms (the supercell on
and a multicellular storm on
2000
CG-producing multicellular storm on
Doppler radars have been synthesized to calculate the three-
dimensional wind field, polarimetric radar variables
have been
combined with thermodynamic soundings to estimate hydrometeor types
throughout the echo volumes, and Lightning Mapping Array (LMA) data
have been sorted into flashes to determine the flash rates and charge
structure for several hours of each storm’s lifetime. The purpose of
this study is to determine the charge structure of each storm,
identify what features are unique for storms that produce
predominantly positive CG lightning, and attempt to reveal the
processes that lead to inverted charge structures and positive CG
lightning.
Refreshments
NCAR-Foothills Laboratory
Bldg 2 Auditorium (Rm1022)