When Hurricane Harvey approached the Texas coast for its first of two landfalls on Aug. 25, a new and advanced weather satellite watched its every move. The spacecraft, known as GOES-16, is still in an experimental phase, but the data it provides is available to National Weather Service (NWS) forecasters already.
As meteorologists test out the capabilities of this new platform, which launched last year, they are revealing new insights on storm systems. With Harvey, the satellite’s lightning mapper — which tracks lightning over land and out to sea, where current observations fall short — revealed something fascinating.
Here’s a video posted by the National Oceanic and Atmospheric Administration (NOAA), which operates the satellite, on Thursday. The yellow flashes represent lightning strikes, either cloud-to-ground discharges or cloud-to-cloud. As with most hurricanes, you’ll notice that the most active area of lightning production is well away from the center of the storm.
Look carefully at this loop, because as the storm intensified and made landfall, it was producing a remarkable amount of lightning right next to its center, within the formidable eye wall. This lightning was occurring in the region of the storm that contains the most powerful winds and some of the heaviest rains. Usually, this region of a hurricane doesn’t have much lightning, due to the internal structure of the clouds.
Studies have shown that lightning rates inside the eye wall may be an indicator of whether a storm is intensifying or weakening, with more lightning seen prior to and during phases when a storm is getting stronger. In this case, the storm reached Category 4 status in the hours prior to making landfall, and lightning rates appeared to spike during this period.
The lightning video that NOAA released matches observations from the ground, since storm chasers positioned near the hard hit community of Rockport, Texas, reported numerous flashes of lightning in the vicinity of the eerily calm eye.