Observations of the Overland Reintensification of Tropical Storm Erin (2007)

Atlantic Tropical Depression Five (2007) briefly strengthened into Tropical Storm Erin over the western Gulf of Mexico shortly before making landfall as a tropical depression near Corpus Christi, Texas, on the morning of 16 August 2007. During the overnight hours of 18–19 August 2007, nearly 3 days after landfall, Erin's remnant circulation strengthened over western Oklahoma, where sustained winds near the circulation's center exceeded 18 m s−1 for more than 3 h—the strongest reported during Erin's entire life cycle. Likewise, station pressure values reduced to sea level were lower at several measurement sites on 19 August than those recorded while Erin was classified by the National Hurricane Center as a tropical cyclone. During this period of lowest pressure, Erin developed an eye, an eyewall structure, and spiral bands, as observed by radar. The reintensification occurred within the domain of multiple observing networks and platforms, which provided rich detail on the near-surface behavior of Erin and embedded processes. Erin's reintensification was not only unique in its magnitude, but also in the breadth of related available observations. This manuscript describes the intensification of Erin over western Oklahoma as observed by the Oklahoma Mesonet (1-min resolution), the Fort Cobb and Little Washita micronets of the U.S. Department of Agriculture Agricultural Research Service Grazinglands Research Laboratory, and the National Weather Service's upper-air, Doppler radar, and surface observing networks.