Lightning and Thermodynamic Profile Observations during the June 2012 Derecho

The June 2012 mid-Atlantic and Midwest Derecho was one of the most destructive and deadly fast-moving severe thunderstorm events in North American history. The derecho produced wind gusts approaching 100 miles per hour as it traveled more than 600 miles across large sections of the Midwestern United States, the central Appalachians and the Mid-Atlantic States on the afternoon and evening of June 29, 2012 and into the early morning of June 30, 2012. It resulted in 22 deaths, widespread damage and left millions without power for many days throughout the region. We present a bow echo location and intensity video derived from lightning observations and instability measurements derived from microwave radiometer observations providing unique perspective on the evolution of this historic storm. For example, ~5,000 J/kg CAPE was derived from radiometer observations at Germantown, Maryland ten hours before storm passage, and ~80 knot Wind Index was derived seven hours before passage (see Figures). Lightning and thermodynamic profile observations were provided by Earth Networks. The Total Lightning network incorporates advanced location technology that detects both in-cloud and cloud-to-ground lightning. The Boundary Layer network uses microwave profilers providing continuous temperature and humidity soundings with radiosonde-equivalent observation accuracy, and unique liquid soundings. This case study illustrates the promise for severe storm forecast and Nowcasting improvements based on lightning and thermodynamic profile observations.