A late night tornado passed through the town of San Augustine, TX during the evening of 24 April 2019. GOES-16 GLM Flash Extent Density data showed a significant increase in lightning activity (lightning jump), during the 10-20 minute period prior to the tornado LSR at 0420 UTC on the 25th. Below are examples of the 1-min FED product (Fig 1), as well as the 5-min accumulation FED product (updating every 1-min as well; Fig 2), which provides a smoother view of the lightning trends. The rapid increase in lightning is distinguishable in both products with this case. ABI IR (gray-scale), tornado (red) and severe thunderstorm (yellow) warnings, along with the Tornado LSR (yellow symbol), are also included in both animations. The graphs below show the rapid increase in FED and peak prior to 0420 UTC (Fig 3).
Bill Line, NWS