Hurricane Edith (1971) - Meteorological History

Meteorological History

A tropical wave moved off the coast of Africa near Dakar on August 31. It moved westward into the Intertropical Convergence Zone, and organized into a tropical disturbance on September 2 with a small, circular area of convection. The system moved to the west, and on September 3, the convection diminished after moving west of 40° W. By the next day, the tropical disturbance was barely discernible from the clouds of the Intertropical Convergence Zone. The wave gradually became detached from the ITCZ, and based on a reconnaissance flight that confirmed the existence of a low-level circulation, it is estimated the system developed into a tropical depression on September 5 while located 255 miles (415 km) east of Grenada.

The depression moved westward quickly, and moved through the southern Lesser Antilles early on September 6. The southern portion of the circulation passed over northeastern Venezuela, though after entering the Caribbean Sea, another reconnaissance flight was unable to confirm the existence of a low-level circulation. Shortly thereafter, while moving into an area of light wind shear, it was able to organize and strengthen further, and on September 7 the depression strengthened into Tropical Storm Edith near the island of Curaçao. While initially, a cold-core upper-level low persisted about 750 miles (1200 km) northwest of the storm, Edith moved west-northwestward due to the influence of a narrow and persistent ridge of high pressure, which extended from the southwestern Atlantic Ocean to the Gulf of Mexico. As the storm continued into open waters of the Caribbean, the upper-level low gradually weakened and was replaced with an anticyclone. This allowed the storm to strengthen further, and on September 8, Edith became a hurricane in the south-central Caribbean Sea.

On September 9, the storm rapidly intensified, and within 24 hours, Edith strengthened from a minimal hurricane to a powerful 160 mph (260 km/h) Category 5 hurricane just off the coast of Nicaragua. The cause for the explosive deepening is unknown, though it is speculated that the transformation in the upper troposphere from an upper-level low to an anticyclone led to a release of baroclinic energy. Reconnaissance aircraft crews in the peak of the storm reported extreme turbulence, causing concern for the safety of the crews. At its peak intensity, the very well-defined "pinhole" eye was only 5 miles (8 km) in diameter. Late on September 9, Hurricane Edith made landfall on northeastern Nicaragua at Cabo Gracias a Dios.

Hurricane Edith rapidly weakened over the mountainous terrain of northeastern Central America, and 18 hours after it made landfall, it emerged into the Gulf of Honduras as an 80 mph (130 km/h) Category 1 hurricane. It continued to weaken as it moved northwestward, and made landfall near Belize City with tropical storm winds of 70 mph (115 km/h). Edith weakened further while crossing the Yucatán Peninsula, and emerged into the Gulf of Mexico near Campeche, Mexico late on September 11 as a minimal tropical storm. Edith initially failed to re-intensify as it moved northwestward, despite low amounts of wind shear and warm waters. This was because an anticyclone over the Gulf was closely connected with Hurricane Fern, which developed and moved over the northwestern portion of the Gulf of Mexico. The anticyclone resulted in an easterly upper-level flow across Edith, creating conditions not conducive for intensification. As Fern moved inland over Texas, the flow became more favorable around Edith, and 36 hours after entering the Gulf of Mexico, the storm began to reintensify slightly.

Edith continued moving to the west-northwest, heading towards the coast of Mexico, but early on September 14, the storm stalled while located just off the coast of Tamaulipas. A mid-latitude trough of low pressure approached the storm, and caused Edith to turn to slowly drift towards the northeast. Located only miles from the Mexican coast, Edith again failed to strengthen until September 15, when it accelerated northeastward and regained hurricane status. The hurricane turned to the east-northeast as it approached the coast of Louisiana, and made landfall on September 16 in a sparsely populated area 30 miles (48 km) east of Cameron with winds of 105 mph (170 km/h), equivalent to a Category 2 hurricane in the Saffir-Simpson Hurricane Scale. Edith rapidly weakened over land, degenerating into a tropical storm over Louisiana, and into a tropical depression over Mississippi. It continued to the east-northeast, and dissipated over northwestern Georgia on September 18.