Improving Real-time Tropical Cyclone Rapid Intensification Forecasts with Total Lightning Data

With the impending launch of GOES-R, a new capability for total lightning detection will become available via the onboard Geostationary Lightning Mapper (GLM).  The GOES-R GLM will map total lightning activity continuously over the Americas and adjacent ocean regions.  Both theory and observations suggest that total lightning flash rates are related to the development of deep convective towers.  As such, the GLM will provide forecasters with a new tool for monitoring hot tower activity in tropical cyclone (TC) inner core regions which may give insights into TC structure and intensity change.

In the last few years, work has been underway to explore how total lightning can be incorporated into current TC intensity and genesis forecast aids.  These aids currently use lightning data from a ground-based network that has a low detection efficiency over the ocean and detects mainly cloud-to-ground strikes.  By comparing lightning activity from different ground networks with different detection efficiencies and abilities to detect total lightning, we have gained insight into what differences forecasters can expect to see when viewing TC lightning from the GLM.  We have also tested quasi-total lightning predictors in the Rapid Intensification Index and found that, as hypothesized, GLM total lightning density will provide different and possibly better predictors of rapid intensity change in tropical cyclones.