Hurricane Bertha (2008) classified as a tropical depression by 06:00 UTC on July 3, located about 255 miles (410 km) south-southeast of Cabo Verde. The NHC noted that global modelling suggested the possibility of tropical development over a week prior, a "remarkable achievement" at the time. The storm's cloud pattern continued to coalesce, and it was upgraded to Tropical Storm Bertha six hours later. On the southern periphery of a mid-level ridge over the open Atlantic, Bertha moved swiftly west-northwest to northwest for several days. Despite being embedded within an environment of low vertical wind shear, the storm passed over ocean temperatures near
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