Operational Lightning Products Improve Forecasting Capabilities in OPC and TAFB Offshore Zones

The National Weather Service’s Ocean Prediction Center (OPC) and the Tropical Analysis and Forecast Branch (TAFB) at the National Hurricane Center (NHC) forecast maritime thunderstorms in “offshore zones” year-round.  These thunderstorms pose daily threats to mariners that traverse the Atlantic waters off the U.S. East Coast, the Gulf of Mexico, and the Caribbean.  More accurate navigation tools (e.g., GPS) and weather prediction of general wind and wave conditions have helped facilitate recreational boaters to travel farther offshore to fish or sail.  These mariners often must navigate around or through approaching storms as they seek safe haven on shore. The offshore oil industry operates hundreds of platforms and support vessels of all sizes in the very active convective areas of the Gulf of Mexico.  A broad variety of marine activities are vulnerable to strong winds, building seas, and reduced visibility associated with strong convective storms.

The OPC and TAFB have selected offshore convective storms as a focus area for the NOAA’s Satellite Proving Ground (PG) for Marine, Precipitation, and Satellite Analysis to help improve their short term prediction of thunderstorms. A variety of convection targeted GOES-R proxy products are being evaluated in operations to prepare for the increased temporal sampling, imager, derived products, and the Geostationary Lightning Mapper (GLM).

The OPC and TAFB have had to rely on satellite imagery and limited lightning strike data to identify the convective characteristics of thunderstorms in offshore waters of the Atlantic Ocean due to the limited range of land-based radar and Very High Frequency terrestrial lightning networks.  A GOES-R Lightning Density product has been developed that uses Vaisala GLD360 Lightning Strike counts and provides a gridded, 8 km product that enables forecasters to visualize lightning cores of convective systems in the OPC and TAFB Offshore Zones.  This density product in conjunction with GOES imagery and other Satellite PG products has enabled forecasters to identify and characterize convective mode (i.e. supercells).  Additionally, this characterization has enabled OPC to begin development of an Atlantic supercell climatology.  This presentation seeks to highlight some of the operational uses for the GOES-R Lightning Density product and associated research on these offshore convective events.