NOAA 2000-511
Contact: Keli Tarp


NOAA scientists from the National Severe Storms Laboratory and the National Weather Service will join researchers from about a dozen organizations to study thunderstorms and lightning in the High Plains, with the ultimate goal of improving severe weather forecasts.

The Severe Thunderstorm Electrification and Precipitation Studies field program will began Monday, May 22 and will continue through July 16. Each day, NOAA researchers, based out of the National Weather Service Forecast Office in Goodland, Kansas, will target their armada of intercept vehicles toward a storm with severe potential near the Kansas and Colorado border. This area is along the western edge of Tornado Alley, where a semi-permanent dry line makes it an ideal location to focus their research.

The scientists will target primarily supercell thunderstorms; long-lived thunderstorms with deep rotating updrafts that are common during May, June and July on the High Plains. Supercell thunderstorms are considered to be the most dangerous type of storm due to the extreme weather generated, including tornadoes, large hail and flooding.

STEPS scientists have three core areas of interest: how precipitation forms in supercell storms; electricity in supercell storms; and using polarimetric radar to study rain and hail in storms. By combining and coordinating their resources, scientists will gather data on the storms using a network of three Doppler radars, two dual-polarization radars, a T-28 armored aircraft for storm penetration, several mobile sounding systems, mobile ground units including NSSL mobile mesonet vehicles and a deployable lightning mapping system from the New Mexico Institute of Mining and Technology.

Collaborating organizations include: National Center for Atmospheric Research, Colorado State University; New Mexico Institute of Mining and Technology; South Dakota School of Mines; Universities of Colorado, North Dakota, Oklahoma and Florida; Cooperative Institute for Mesoscale Meteorological Studies; and the Cooperative Institute for Atmospheric Research.

NOAA researchers are coordinating several teams within STEPS. One NOAA group, coordinated by Erik Rasmussen, research meteorologist with NSSL in Boulder, Colo., will focus on rotation within the storm as well as the hail and precipitation it produces. His team will drive six mobile mesonets, sedans equipped with weather instruments, to take measurements of wind, temperature and moisture under and near targeted storms. Global Positioning System receivers will keep constant track of each vehicle's exact position. They will gather data continuously from the first "towering cumulus" stage of a storm until it leaves the experiment domain. The data they gather could improve scientists' understanding of how tornadoes form in supercell thunderstorms, leading to better forecasts, detection and warnings of tornadoes.

Another team of NOAA researchers will intercept the same storms to determine the electrical structure of all types of supercell thunderstorms.

"We want to relate the structure to production of lightning – especially positive ground flashes – and their relationship to severe weather," said Dave Rust, lightning and storm electricity researcher from the National Severe Storms Laboratory in Norman, Okla., who is leading the team with Don MacGorman, also from NSSL in Norman.

They will launch weather balloons with electric field meters and radiosondes attached. These instruments will record data from inside the storm, including temperature, pressure, humidity, wind speed and direction and the total electric field as well as the balloon's location. The data collected by the team will help identify uses of lightning flash information for severe weather warnings.

NOAA's involvement in STEPS is funded by the National Science Foundation and the National Severe Storms Laboratory.