Mature and severe storms approached Memphis from the west. The ProbSevere LightningCast model predicts the probability of 1 or more next-hour lightning strikes at any given location. It not only needs to anticipate convective development, but also the short-term movement of thunderstorms.
Figure 1: Animation of LightningCast v2 (contours), GOES-19 ABI day-cloud-convection RGB (background), and GLM flash-extent density (foreground blue-to-orange pixels). The yellow “Home” point and range ring denote the simulated DSS event and 10-mile ring around the event.
In the HWT this year, forecasters are asked to compare LightningCast v1 (ABI-only predictors) and v2 (ABI + MRMS predictors). They also are able to use “lightning dashboards” for on-demand DSS events. The image below demonstrates the time series of LCv1 (red) and LCv2 (green) probabilities at the fireworks show location, along with GLM flash centroids within approximately 10 miles (small blue circles) and 5 miles (large blue circles) of the location. Note how LCv2 probabilities began to jump up about 20 minutes prior to LCv1. Several nearby flashes were observed between 20:30 and 21:00 UTC. From the 75% threshold, LCv2 provided nearly 40 minutes of lead time to the first flash within 5 miles.
Figure 2: Lightning dashboard for the Memphis fireworks show.
When we toggle between LCv1 and LCv2 at 19:51 UTC, we clearly see moderate-to-high probabilities (50-75%+) from LCv2 extending further eastward towards the event (“Home” point), compared to LCv1. This is a subtle but impactful difference that can help forecasters alert event managers in a more timely manner.
Figure 3: Toggle between LightningCast v1 and v2 (parallax-corrected contours) outputs, with GOES-19 ABI day-cloud-convection RGB (background) and GLM flash-extent density (foreground).
- Hail yeah
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