Hurricane Helene (2006)

Hurricane Helene

Category 3 major hurricane (SSHWS/NWS)
Hurricane Helene near peak intensity
Formed	September 12, 2006
Dissipated	September 24, 2006
Highest winds	1-minute sustained: 120 mph (195 km/h)
Lowest pressure	955 mbar (hPa); 28.2 inHg
Fatalities	None
Damage	None
Areas affected	Northern British Isles (while extratropical)
Part of the 2006 Atlantic hurricane season

Hurricane Helene was the ninth tropical storm, fourth hurricane, and strongest hurricane of the 2006 Atlantic hurricane season.

Helene was a long-lived Cape Verde-type hurricane that formed in the extreme southeastern part of the North Atlantic Ocean, peaking as a Category 3 hurricane on the Saffir-Simpson hurricane scale as it traversed the central Atlantic. It never affected land until the very end of its lifespan as a weak extratropical system, which had minor impact in the northern British Isles.

In the second week of September, a strong tropical wave began to emerge off the coast of Africa. It was well-organized from the start, and on September 11, even before it emerged off the coast, the National Hurricane Center believed that it could quickly develop into a tropical depression. That is indeed what happened, and it became Tropical Depression Eight on the morning of September 12. The enormous size of the depression made it fairly slow to develop, combined with some easterly wind shear in the eastern Atlantic and influence of the Saharan Air Layer to the north as it tracked south of the Cape Verde islands. Convection was also slow to build in, with little banding at first. The initial strengthening was delayed as a result. However, on September 13, the organization improved as banding became better defined, and that evening, the depression strengthened into Tropical Storm Helene.

The storm slowly strengthened over the warm waters of the eastern Atlantic thereafter as it tracked west-northwest. Some dry air from the Saharan Air Layer continued to slow development on September 14 as Helene remained a low-end tropical storm. However, a bout of intensification took place on September 15 as shear diminished. The storm became much better organized with well-defined banding, and leveled off that evening at just under hurricane intensity. On the morning of September 16, the storm began to develop a ragged eye, and the storm strengthened to hurricane status. The intensity leveled off for a while as a marginal Category 1 hurricane, as the intensification was slowed by the presence of moderate wind shear despite the absence of significant dry air. Late that evening, the storm began to slowly intensify once again.