The event in this blog post was provided by Amanda Terborg, satellite champion at the Aviation Weather Center.
SPoRT has been coordinating with the Aviation Weather Center (AWC) for a little over a year to incorporate the pseudo-geostationary lightning mapper (PGLM) mosaic demonstration product in operations, derived from ground-based lightning mapping arrays and part of the GOES-R Proving Ground. This work culminated with the transition from demonstration mode to the AWC’s operations floor in September, thanks to Amanda’s coordination. Shortly thereafter we received this particular event from October 7th.
On this day, one of the major items of interest was a line of storms moving through Washington D.C. and northern/western Virginia (Fig. 1). The storms were not creating major disruptions as flights were able to remain ahead of the line or work their way behind the line of storms. Figure 2 shows the aircraft tracks from 1402 UTC, which corresponds to the radar image in Fig. 1. Due to the different projection types in N-AWIPs, the primary point of interest is circled in each image. The major item of note is that there are no National Lightning Detection Network (NLDN) cloud-to-ground strike observations in the entire image. However, the circled region shows a cluster of 3-4 flashes observed by the PGLM product. As there are no corresponding NLDN strikes, these are solely intra-cloud flashes. By observing the flight tracks, the aircraft were flying behind the main line of highest reflectivities. Although the aircraft were behind the main line, Fig. 2 shows that approximately five aircraft flew into the region where the PGLM flashes were observed. At around 1400 UTC one of those flights was struck by lightning. The best news was that, while struck, the aircraft suffered no damage and continued safely on to its destination.
This example shows one of the major benefits of the future GOES-R Geostationary Lightning Mapper (GLM), as a space-borne instrument capable of observing total lightning (both intra-cloud and cloud-to-ground). Radar is an excellent tool for helping develop safe flight tracks. The ability of total lightning to observe intra-cloud flashes, as well as the spatial extent of these flashes, gives aviation planners additional information as to how to route aircraft, particularly in storms that have no cloud-to-ground observations. This will be very important in data sparse regions were radar and total lightning are currently not available.