LightningCast v1 vs. v2 in Texas and Alabama

The LightningCast model predicts next-hour probabilities of lightning. Version 1 (LCv1) of the model uses solely GOES-R ABI inputs (C02, C05, C13, and C15), whereas the experimental version 2 (LCv2) incorporates MRMS Reflectivity -10C in addition to the four ABI image-inputs.

While LCv1 provides accurate predictions in most circumstances, LCv2 significantly improves predictions under thick ice. This case in Texas demonstrates much higher probabilities from LCv2 (left, animation below) under a plume of thick ice with very little cloud-top texture or temperature contrast. The convection underneath was likely somewhat shallow, as storm tops were not poking out from the residual thick ice, but still produced lightning for several hours. 

LCv2 (left) and LCv1 (right) probabilities (contours), GOES-19 ABI day-cloud-phase-distinction RGB, and GOES-19 GLM flash-extent density observations over north Texas and southern Oklahoma.

Meanwhile in Alabama, cumulus clouds bubbled up along what appeared to be a residual thunderstorm outflow boundary. LCv2 consistently produced probabilities 10-20% higher than LCv1 for the congestus clouds that would go on to produce frequent lightning.

LCv2 (left) and LCv1 (right) probabilities (contours), GOES-19 ABI day-cloud-phase-distinction RGB, and GOES-19 GLM flash-extent density observations over eastern Alabama.

This convection happened to develop right over Anniston Metropolitan Airport in eastern Alabama. The lightning dashboard at that site plots both the LCv1 (red) and LCv2 (green) probabilities produced by the 5-minute CONUS sector (below). We can see that LCv2 consistently held higher probabilities 10-15 minutes prior to when LCv1 achieved the save likelihood. LCv2 had an elevated probability of lightning (>30%) about 50 minutes prior to the first GLM flash within 5 miles of the airport.

Lightning dashboard for Anniston Metropolitan Airport, with LCv1 (red) and LCv2 (green) probabilities, and GLM flash rates within 10 miles (small blue dots) and 5 miles (large blue dots) of the airport.

Scientists are working to evaluate and improve LightningCast where we have good MRMS data, while maintaining good skill and first-flash lead time where only GOES is available.