Total lightning observations and tools for the 20 May 2013 Moore, Oklahoma, tornadic supercell

Abstract

On 20 May 2013, a supercell thunderstorm developed west-southwest of Newcastle, Oklahoma, and eventually produced an EF-5 tornado that struck Moore, Oklahoma. This article describes how total lightning observations associated with this rotating storm could benefit warning operations. This effort focuses on (i) the Geostationary Operational Environmental Satellite-R pseudo-geostationary lightning mapper product, (ii) the National Aeronautics and Space Administration's Short-term Prediction Research and Transition Center/Meteorological Development Laboratory's total lightning tracking tool, and (iii) a real-time lightning jump algorithm currently under development. Use of these three tools revealed a distinct increase or "jump" in the storm's lightning flash rates prior to reported severe weather. Lightning jumps occurred 19 min prior to severe hail and coincided with the storm's initial growth, while the second lightning jump occurred 26 min prior to tornado touchdown. This second jump accompanied an increase in rotational depth and strength. These rapid increases in total lightning activity can provide improved situational awareness to forecasters, as lightning jumps relate to the rapid strengthening of a storm's updraft and serve as a precursor to the stretching of the storm vortex prior to severe weather events. Although lightning jumps alone do not always indicate imminent severe weather, they (i) have the potential to help reduce false alarms and (ii) can guide forecasters to issue warnings earlier than they would have with radar data alone.

Anomalous Lightning Behavior During the 26–27 August 2007 Northern Great Plains Severe Weather Event

“…Note the increase in median peak currents especially in SC2–SC6. As previously suggested, it is likely that these storms in particular experienced an increase in updraft strength (e.g., intensification) at nearly the same time which gave rise to a general surge in total and positive CG lightning strokes (Stano et al, ; Stough et al, ; Tessendorf et al, ).…”

“…Due to their close proximity, SC2a and SC2b began to interact with one another as given by the 5 dBZ increase in mean N30 just after 0100 UTC which lasted for nearly 20 min (Schultz et al, ). Schultz et al () pointed out that the increase in reflectivity at 0110 UTC was around the time the cells had begun to merge likely leading to an increase in updraft intensity along with increased ice/graupel formation (MacGorman et al, ; Stano et al, ; Stough et al, ). The NLDN observations corroborated the increase in updraft strength because the total CG lightning stroke rate (Figure b) did indeed show a well‐defined negative CG lightning stroke rate increase (~30 strokes per minute) between 0100 and 0120 UTC (before supercell merger), while the positive CG lightning stroke rate increased to nearly the same magnitude (27 strokes per minute) between 0135 UTC and 0140 UTC (completed supercell merger).…”

“…Lightning activity can be useful in diagnosing the behavior of thunderstorms (Lyons et al, ; Orville et al, ; Stough et al, ; Wang et al, ). For example, a sharp increase (or decrease) in lightning activity often occurs minutes before a severe weather event is observed (e.g., large hail, tornado, and severe wind gust) (Emersic et al, ; Schultz et al, ; Strader & Ashley, ; Stano et al, ; Williams et al, ). These increases and decreases in lightning flash rates have been well documented and are frequently used in forecasting algorithms to determine whether a storm is gaining or losing strength which is vital for human safety (Barth et al, ; Gatlin & Goodman, ; Schultz et al, ; Stough et al, ; Williams et al, ).…”

Rapid Refresh Information of Significant Events: Preparing Users for the Next Generation of Geostationary Operational Satellites

“…Knowledge of rapidly changing lightning patterns in developing storms enhances the situational awareness of forecasters and helps inform decision makers regarding severe weat her a nd light ning threats. These lightning channel VHF source data have been resampled to the GLM nadir pixel resolution of 8 km to produce a pseudo-GLM f lash extent density grid updated every minute (Goodman et al 2012;Stano et al 2014). The f lash extent density product is then combined with GOES-14 visible SRSOR information to illustrate a potential new blended product that could be provided to weather forecasters and broadcast meteorologists in the GOES-R era (Fig.…”

Impacts to Aviation Weather Center Operations Using Total Lightning Observations from the Pseudo-GLM

“…With the launch of GOES-R expected in 2016 there is a need for forecasters and aviation operators to become accustomed to these new data. To address this, NASA's Short-term Prediction Research and Transition center (SPoRT; Darden et al 2002;Goodman et al 2004;Jedlovec 2013) has developed a pseudo GLM (PGLM; Stano et al 2010Stano et al , 2011Stano et al , 2012Stano et al , 2014 product by utilizing the Lightning Mapping Array networks across the CONUS. This product has become the de facto training and demonstration GLM dataset for the GOES-R Proving Ground (Goodman et al 2012).…”