Hurricane Bertha (2008) weakened to a tropical storm on July 13, and a large upper-level low over the central Atlantic steered it east and southeast. After generally maintaining its strength for several days, an eye redeveloped and convection became more symmetric about the feature on July 18, prompting the NHC to upgrade Bertha to a hurricane around 18:00 UTC that day. The storm rapidly accelerated ahead of a trough off the East Coast of the United States, forcing Bertha into rapidly cooler waters. Its wind field became extremely asymmetric and deep convection near the center dissipated, indicative of an extratropical transition that Bertha
Hurricane Bertha (2008) 77 °F (25 °C), and its overall appearance was characterized by intermittent bursts of deep convection near the center. Eventually, by late on July 5, Bertha began to enter warmer waters and gain organization. Convection coalesced throughout July 6, and a series of microwave passes later that day indicated the formation of an eye-like feature, despite some tilt to Bertha's low- and mid-level circulations. Rapid deepening ensued as the aforementioned eye became readily apparent and convection in the eyewall cooled; Bertha became the season's first hurricane around 06:00 UTC on July 7, and by 21:00 UTC that afternoon, attained its