Hurricane Lorenzo (2007) - Meteorological History

Meteorological History

The origins of Hurricane Lorenzo were from a tropical wave that exited the coast of Africa on September 11. After moving across the tropical Atlantic Ocean, it traversed much of the Caribbean Sea before developing an area of thunderstorms on September 21. The system developed a low pressure area on September 23 after the northern portion of the wave broke off and crossed the Yucatán Peninsula. Initially, a Hurricane Hunters flight was scheduled to investigate the system, although the low became disorganized over the southeastern Gulf of Mexico due to high wind shear. However, the wind shear decreased, and late on September 25, another Hurricane Hunters flight indicated the development of a closed low-level circulation. Based on that observation, along with sufficient persistence of the thunderstorms, the system developed into Tropical Depression Thirteen about 190 mi (305 km) east of Tampico, Tamaulipas.

Upon developing, the depression was located in an area of weak steering currents, resulting in an erratic movement generally to the south. In its formative stages, the depression executed a small loop. As it did so, it moved into an area of very warm waters and decreasing wind shear. The depression's convection gradually organized, although the winds were slower to increase. An anticyclone became established over the system, and the depression intensified into Tropical Storm Lorenzo at around 1200 UTC on September 27. At the time, it was located about 150 mi (240 km) east of Tuxpan, Veracruz, moving steadily westward under the influence of a building ridge to its east. As it approached the coast, Lorenzo rapidly intensified unexpectedly, and within 12 hours of attaining tropical storm status it strengthened into a hurricane.

Hurricane Lorenzo quickly developed a closed eyewall, which was observed on radar and provided a peak intensity estimate of 80 mph (130 km/h) at 0000 UTC on September 28. The cyclone maintained vigorous and symmetric convection across the center, although the structure deteriorated slightly before Lorenzo crossed the coast near Tecolutla, Veracruz at 0500 UTC that day, with winds estimated around 75 mph (120 km/h). After making landfall, the hurricane rapidly weakened to tropical depression intensity. Progressing inland, the circulation became difficult to locate as the convection diminished to rainbands along the coast. Within 19 hours after moving ashore, the circulation of Lorenzo dissipated, therefore ending its duration as a tropical cyclone.