1. Hurricane Michael Landfall GOES and NEXRAD Observations 10 October 2018

17. Downburst

19. Eye Wall

20. Convective storm core Convective storm core T T

21. Similarities to Hurricane Frederic (1979) TIROS-N AVHRR band 4 1018 UTC 13 September 1979 From Parrish et al. (1982)

22. Summary During the afternoon of October 10, 2018, strong category three (3) Hurricane Michael made landfall near Panama City, Florida. The eye wall, which is a ring of very intense convective storm activity surrounding the eye of the hurricane, passed directly over Tyndall Air Force Base with a recorded wind gust of 112 knots, while the Panama City Waterfront, five nautical miles northwest, recorded a downburst wind gust of 93 knots. Slides 14-15 display Geostationary Operational Environmental Satellite (GOES)-16 Advanced Baseline Imager (ABI)-derived products (split-window infrared (IR) channel brightness temperature difference (BTD)) and associated NEXRAD reflectivity imagery near the time of hurricane landfall and eye-wall passage at Panama City. NEXRAD reflectivity imagery displays that the left half of the eye-wall had evolved into a westward-oriented bowing configuration while split-window IR BTD indicates the presence of significant midtropospheric dry-air circulating northwestward toward a new developing convective storm core immediately inside the eye wall. This type of convective storm evolution pattern was first identified with the landfall of Hurricane Frederic in September, 1979 near Mobile, Alabama and was associated with downburst wind occurrence. Similarly, during the landfall of Hurricane Michael, a new developing convective storm core over the coastal region of Panama City near Tyndall Air Force Base produced damaging downburst winds as recorded in the wind speed graph in Slide 12.

23. Importance of this Study The case study of Hurricane Florence landfall illustrates the mesoscale features of tropical cyclone structure and demonstrates the ability of the GOES-16 ABI in resolving and indicating favorable conditions for severe convective wind occurrence within a hurricane. This study also supports NOAA’s mission “To understand and predict changes in climate, weather, oceans, and coasts” and supports NOAA’s enterprise objective “A holistic understanding of the Earth system through research”.