Wednesday, September 11, 2024

Tropical Storm Gordon (2024)

Storm Active: September 11-17

A disturbance over the eastern Atlantic crossed the Cabo Verde Islands around September 10, bringing scattered rains to the islands. The next day, the system developed a closed circulation and was classified Tropical Depression Seven. The cyclone was small, with little in the way of thunderstorm activity, and organized only slowly as it moved steadily west-northwest. It wasn't until early on September 13 that it strengthened into Tropical Storm Gordon. Convection had increased with the storm, but was slightly displaced from the center by moderate wind shear out of the west. As a result, the cyclone did not manage to strengthen much, and reached peak winds of 45 mph on September 14.

Gordon entered a drier air mass shortly thereafter and began weakening again as it slowed down and turned slightly south of west under the influence of a ridge of high pressure. It became a tropical depression on September 15. Though weakening temporarily halted that evening, Gordon was never able to fully recover. Thunderstorm activity became more and more diffuse, and the center became less defined until it dissipated altogether on September 17.



The image above shows Gordon just after it was named.



Gordon was stifled by wind shear and dry air as it crossed the central tropical Atlantic.

Monday, September 9, 2024

Hurricane Francine (2024)

Storm Active: September 9-13

A tropical wave crossed the Atlantic Ocean during the last week of August without developing significantly. It made its way across the Caribbean and the Yucatan Peninsula before finally showing signs of organization in the Bay of Campeche a week into September. When the disturbance first entered the bay on the 7th, it was interacting with a cold front, and the area of low pressure was poorly defined. The system was producing vigorous storm activity though, and by the next day was also generating sustained winds to gale force. The inner structure of the disturbance improved markedly during the morning of September 9 and it was named Tropical Storm Francine.

The storm moved slowly northwest that day around the periphery of a ridge centered over Cuba. It took advantage of the warm waters of the Gulf of Mexico and began to strengthen. That night, an intrusion of dry air caused the core convection to collapse and temporarily hindered intensification. Deepening resumed the next morning and Francine turned toward the northeast as it began to feel the approach of a trough from the northwest. The evening of the 10th, the storm was upgraded to a category 1 hurricane. The storm accelerated toward the northeast overnight and wind shear began to increase as the storm neared the Louisiana coastline. As a result, the core took on a somewhat lopsided appearance. Nevertheless, Francine reached a peak category 2 intensity of 100 mph winds and a central pressure of 972 mb that afternoon just before landfall in central Louisiana.

Once inland, the storm rapidly weakened. It weakened to a tropical depression on September 12 over Mississippi and became post-tropical that afternoon. After that, the remnants slowed down and moved erratically across the interior southeast. This brought a sustained period of heavy rain to the region, especially northern Mississippi, until dissipation occurred a few days after.



The image above shows Francine just before landfall.



Francine's impacts were mitigated by the fact that it made landfall in a sparsely populated region and weakened quickly after landfall.