Oklahoma Lightning Mapping Array
Real-time LMA Images from WDSS-II
The Oklahoma Lightning Mapping Array (OKLMA) provides
three-dimensional mapping of lightning channel segments over west central
Oklahoma and two-dimensional mapping of all lightning over most of
Oklahoma. Up to thousands of points can be mapped for an individual
lightning flash, to reveal its location and the development of its
structure. NSSL scientists hope to learn more about how storms produce
intra-cloud and cloud-to-ground flashes and how each type is related
to tornadoes and other severe weather. Better lightning mapping techniques
show that some supercell thunderstorms have "lightning holes" where
updrafts are located and precipitation is scarce. If these holes form,
as suspected, just before a storm becomes severe, this information
could alert forecasters to developing severe conditions. The OKLMA
was an integral part of the 2003 and 2004 Thunderstorm
Electrification and Lightning Experiment (TELEX).
Lightning Mapping Stations
Crosses indicate the locations of the eleven stations
of the Oklahoma Lightning Mapping Array (OKLMA). The inner red
circle indicates the region within which the system provides accurate
three-dimensional locations of lightning channel segments. Up
to thousands of points can be mapped for an individual lightning flash,
to reveal its location and the development of its structure. Height
errors increase rapidly with range beyond the red circle and obscure
details in the vertical lightning structure there. The outer
gold circle indicates the nominal region within which the OKLMA provides
two-dimensional locations. At longer ranges, some lightning is
still detected, but radial errors in the mapped locations become large. The
blue circle centered on the KOUN polarimetric radar indicates the region
within a 60 km range, where the resolution of polarimetric radar data
is optimal. Black lines indicate major highways. (larger image)
Oklahoma Lightning Mapping Array site north of Chickasha, OK
The VHF antenna on the right receives signals in
the channel 3 television band. This signal is processed by electronics
in the small plastic building on the left of the picture to determine
the time at which the signal is received to within less than a millionth
of a second. This time and information about the signal is then
sent back to a central processor in Norman via the communication antenna
beside the plastic building. The central processor records the
information from all stations and, in real time, uses the times from
several antennas to determine the three-dimensional location at which
a lightning channel segment radiated the signal. These data
are being used with radar and other storm measurements in scientific
studies to help understand how thunderstorms produce lightning and
to develop ways of using lightning mapping data to warn and forecast
of weather hazards. (larger image)