HOUSTON (CW39) – From previous research we know that lightning is a good proxy for hurricane intensification. However, later studies showed that not only was lightning indicative of intensifying storms, but also prevalent in weakening storms. Therefore, increased lightning is a sign that CHANGE is happening.
NASA’s Marshall space flight center in Huntsville Alabama is doing more research on this phenomenon.
“We have gone in and used some of the new geostationary lightning data, and we have gone beyond just counting flashes. GLM (Goes Lightning Mapper) provides information on the size of the lightning and it’s optical intensity,” says Christopher Schultz, a lightning researcher at NASA’s Marshall Space Flight Center.
Optical intensity is simply how bright a flash is. In hurricane Dorian, leading up to peak intensity flashes were brighter, larger, and closer to the center of the storm. After peak intensity lightning still occurred, but in a separate way.
“They were a little bit smaller and a little bit weaker. That’s because the vertical motion in the storm had changed.” Schultz adds.
We can get information about the vertical profile of a storm through ground-based radar data and supplemental modeling when a storm approaches closer to the U.S. coast. Data is a little harder to come by far out to sea.
Schultz says, “Over the open ocean, lightning responds to that vertical motion. You need that vertical motion to generate the electricity in the storm.
Therefore, when lightning is amplifying in the center of the storm, we can conclude rapid intensification when ground-based data is lacking. Long term track forecasting is fairly accurate when talking about the 24–48-hour range. It is the short term, intensity forecasting, where this information is most helpful.
“The intensity is where they are still working to be better at. We are trying to add that piece to the puzzle to help them be more confident on the intensity forecast. Especially in the short term, 0-3 hours”, Schultz.
Cloud to cloud lightning is more common in the inner core, while cloud to ground is more common within the outer bands. The friction of a storm making landfall can also generate more lightning strikes. In 2017 hurricane Harvey was a good example of this.