Hurricane Kirk (2024)

Storm Active: September 29-October 7

Around September 25, a large tropical wave entered the Atlantic. After passing through the Cape Verde islands, the disturbance began more organized; it was classified Tropical Depression Twelve on September 29. The next day, it strengthened into Tropical Storm Kirk. The storm was moving west at first, but soon began to arc very gradually toward the north. Kirk was a sprawling storm and was a little disheveled on satellite imagery due to some wind shear, but it nevertheless intensified steadily. On October 1, it became a hurricane. Kirk was located at 40.1° W when it reached hurricane strength, far surpassing the previous record easternmost tropical Atlantic hurricane formation in October (a record previously shared by Jose of 1999 and Tammy of 2023). That record stood for all of three days until it was again far surpassed by Hurricane Leslie.

Kirk didn't stop there, however. The large hurricane deepened much further over the following days, especially during a rapid burst of intensification beginning on the evening of October 2, when the eye quickly cleared on satellite imagery and became a major hurricane. The following afternoon, it reached category 4, and late on October 3, Kirk achieved a powerful peak intensity of 145 mph winds and a central pressure of 934 mb. The next day, the storm's steady northwest heading brought it into an area of higher shear from an upper-level low to the northwest. A gradual weakening trend began. The storm turned north and began to accelerate as it felt the tug of the mid-latitude westerlies.

Even as the core lost its definition and the peak winds decreased, Kirk's windfield grew as it gained latitude, pushing large waves to coasts all around the Atlantic. It lost major hurricane status on October 6 and turned northeast. Increasingly hostile upper-level winds soon began extratropical transition. The storm became post-tropical during the morning of October 7. What was left of Kirk eventually brought rain and strong winds to parts of western Europe a few days later.

The image above shows Kirk as a category 4 hurricane over the open Atlantic on September 4.

Despite being a large hurricane, Kirk did not directly affect land as a tropical cyclone.

Tropical Storm Joyce (2024)

Storm Active: September 27-30

On September 22, another tropical wave left Africa and entered the eastern tropical Atlantic. Within a few days, the disturbance was close to tropical storm status, but the center was not well-defined enough. It took a few more days for the system to clear the final hurdle and become Tropical Storm Joyce on September 27, when it was located around halfway between Africa and the Leeward Islands. Joyce intensified modestly in the day after its formation and turned northwest into a weakness in the subtropical ridge. However, the system soon encountered increasing wind shear and began to weaken by September 29.

Late that same day, it weakened to a tropical depression. Though the storm continued to produce bursts of thunderstorm activity, the center became less and less defined and eventually dissipated late on September 30.

Joyce was a small tropical storm; the image above shows a satellite image from September 27.

Joyce was a short-lived tropical storm that did not affect any land areas.

Hurricane Isaac (2024)

Storm Active: September 25-30

Around September 20, a frontal boundary moved into eastward into the Atlantic ocean from North America. A well-defined non-tropical low formed along the boundary and passed north of Bermuda on September 23. Deep convection increased near the center over the next couple of days and the circulation separated from the front. The system was named Tropical Storm Isaac late on September 25 over the central tropical Atlantic.

Isaac rode the clockwise flow east-northeast around the north side of the subtropical ridge and encountered enough upper-level divergence and instability to support strengthening even over marginally warm sea surface temperatures. The storm reached hurricane status early on the 27th and an eye began to intermittently appear on satellite imagery.

Surprisingly, Isaac had a few more tricks up its sleeve, and intensified even further overnight. The eye became better defined and the surrounding area of convection larger and deeper. The storm peaked at category 2 strength on September 28 with peak winds of 105 mph and a central pressure of 968 mb. It turned northeast and began to pass over markedly colder water soon after. This began a period of gradual weakening, which brought Isaac back down to tropical storm strength by the evening of September 29, when it was passing northwest of the Azores. Beyond rough seas, there was no direct impact to the islands. Cold water and increasing shear brought about Isaac's transition to a post-tropical cyclone on September 30. The remnants continued northeastward until they dissipated west of Ireland.

The image above shows Isaac as a category 2 hurricane.

Isaac was impressively strong for its latitude, but did not affect any land areas.

Hurricane Helene (2024)

Storm Active: September 24-27

A large area of low pressure developed just east of central American around September 22. The sprawling system drifted generally northward, but the counterclockwise flow brought extreme rains especially to the Pacific coasts of Nicaragua, Honduras, and El Salvador. The next day, the disturbance began to organize over the eastern Caribbean, but lacked a defined center. On the 24th, it became organized enough to be named Tropical Storm Helene.

When Helene formed, its center was exposed to the west of the main convective mass due to some shear out of the southwest. However, this shear was already diminishing; high oceanic heat content and atmospheric humidity soon put the storm on a strengthening trend as it moved northwestward. Helene was a large storm, with gale force radii above the 90th percentile of historical Atlantic cyclones at the same latitude. As a result, the core was slow to consolidate, but impacts were very widespread. When the storm passed just west of the northeast tip of the Yucatan Peninsula during the morning of September 25, tropical storm force winds already extended more than 250 miles from the center in some directions. Around the same time, Helene strengthened into a hurricane.

The hurricane began to feel the flow ahead of a trough over the central United States later that day and accelerated toward the north, entering the Gulf of Mexico. Overnight, the core of Helene steadily became better defined and an eye began to emerge. Once the eyewall was well-established, the intensification accelerated on September 26. The storm reached category 2 that morning and became a major hurricane that afternoon. By the early evening, Helene's forward speed had increased to more than 20 mph toward the north-northeast and it was closing in quickly on the Gulf coast. It reached category 4 soon after, reaching a peak intensity of 140 mph winds and a central pressure of 938 mb at landfall in the big bend region of Florida late on September 26, local time.

The large size and fast motion of the storm meant that the storm surge impacts to the concave area of coastline were very severe. On top of that, hurricane-force winds spread far inland and into Georgia before the storm could spin down significantly. The wind damage was severe for a large swath of the southeast, especially just east of the center's path. Helene weakened to a tropical storm over central Georgia and only lost tropical storm status over Tennessee during the afternoon of the 27th; the cyclone became post-tropical that evening. Its remnants slowed to a standstill near the Tennessee valley and slowly diminished, but the combination of Helene-influenced rains before the arrival of the storm and ex-Helene stalling over the area led to some of the storm's heaviest rainfall amounts in the region, especially western North Carolina. What was left of the hurricane finally dissipated by early on September 29.

The image above is a nighttime infrared satellite view of Hurricane Helene at peak intensity as a category 4 hurricane just before its landfall in Florida. The storm's uncommonly large windfield caused widespread damage.

Helene was a relatively short-lived but large and devastating storm.

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.

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.