Figure 1, below, shows a single image from the attached movie showing the Geostationary Lightning Mapper observations for Hurricane Harvey.
Figure 1: Example image from the attached movie from 0700 UTC on August 25, 2017 while Harvey is a Category 2 hurricane. The image shows the 11.2 micron infrared imagery in grey scale (background) and the GLM group density (shaded) accumulated over 15 minutes.
The link to the animation below monitors Harvey from 1400 UTC on August 23, 2017 while it was still a remnant system coming off the Yucatan Peninsula through the initial landfall and heavy precipitation across Texas at 2345 UTC on August 27, 2017. The animation shows the ABI 11.2 micron infrared imagery (using a greyscale color curve to emphasize GLM) as well as the GLM 8 km group density (using the SPoRT color curve tested at the Hazardous Weather Testbed and being prepared as the default, operational curve). Given the length of time covered by the animation, the data are shown at 15 minute intervals. Specifics on Harvey (i.e., maximum winds and minimum pressure) are from the National Hurricane Center’s product archive for this storm. The link is for an mp4 movie and is approximately 62 MB in size.
[62 MB] Hurricane Harvey mp4 link.
Several still images are shown below highlighting interesting features.
One feature is the distribution of the total lightning observations throughout the tropical cyclone and the magnitude of the lightning density. Generally, the total lightning is not distributed throughout the entire storm, but concentrated in bands and sometimes in the eye wall, as seen in Figure 1. Figure 1 can be compared to the early stages when Harvey was upgraded to a Tropical Storm (Figure 2), but also later where many times there is no lightning in the eye wall (Figure 3). Also, please note that the accumulations are for 15 minutes versus 1 or 2 minutes shown in severe weather cases.
Figure 2: This is the same as Figure 1, but for Tropical Storm Harvey at 0415 UTC on August 24, 2017.
Figure 3: This is the same as Figure 1, but at 0815 UTC on August 25, 2017. This is highlighting the distribution of total lightning is mainly in the convective bands and note in the eye wall.
Figure 4 shows Harvey as it makes landfall as a Category 4 hurricane. Here, GLM group density values are on par with the outer convective bands as the eye wall makes landfall.
Figure 4: Same as Figure 1, but at 0215 UTC on August 26, 2017. This image highlights the GLM group density observations in Hurricane Harvey’s eye wall as it makes landfall.
Lastly, after the initial landfall, Figure 5 shows a large increase in the magnitude and spatial area of the GLM group densities in the outer convective band as some of the catastrophic rain impacts the Houston, Texas region.
Figure 5: Same as Figure 1, but at 0245 UTC on August 27, 2017. This image highlights the increased GLM group density magnitude and spatial extent during part of the catastrophic rains that impacted Houston, Texas.
NOTE: NOAA’s GOES-16 satellite has not been declared operational and its data are preliminary and undergoing testing. Users receiving these data through any dissemination means (including, but not limited to, PDA and GRB) assume all risk related to their use of GOES-16 data and NOAA disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.