Hurricane Nadine was the fourth-longest-lived Atlantic hurricane on record. The fourteenth tropical cyclone and named storm of the 2012 Atlantic hurricane season, Nadine developed from a tropical wave west of Cape Verde on September 10. By the following day, it had strengthened into Tropical Storm Nadine. After initially tracking northwestward, Nadine turned northward, well away from any landmass. Early on September 15, Nadine reached hurricane status as it was curving eastward. Soon after, an increase in vertical wind shear weakened Nadine and by September 16 it was back to a tropical storm. On the following day, the storm began moving northeastward and threatened the Azores but late on September 19, Nadine veered east-southeastward before reaching the islands. Nonetheless, the storm produced tropical storm force winds on a few islands. On September 21, the storm curved south-southeastward while south of the Azores. Later that day, Nadine transitioned into a non-tropical low pressure area.
Due to favorable conditions, the remnants of Nadine regenerated into a tropical cyclone on September 24. After re-developing, the storm executed a cyclonic loop and meandered slowly across the eastern Atlantic. Eventually, Nadine turned south-southwestward, at which time it became nearly stationary. By September 28, the storm curved northwestward and re-strengthened into a hurricane. The tenacious cyclone intensified further and peaked with winds of 90 mph (140 km/h) on September 30. By the following day, however, Nadine weakened back to a 65 mph (105 km/h) tropical storm, as conditions became increasingly unfavorable. Strong wind shear and decreasing sea surface temperatures significantly weakened the storm. Nadine transitioned into an extratropical cyclone on October 3, and merged with an approaching cold front northeast of the Azores soon after. The remnants of Nadine passed through the Azores on October 4 and again brought relatively strong winds to the islands.
A large tropical wave emerged into the Atlantic Ocean from the west coast of Africa, on September 7. The system passed south of Cape Verde on September 8, bringing disorganized showers and thunderstorms. Around that time, the National Hurricane Center gave the system a medium chance of tropical cyclogenesis within 48 hours. A low pressure area developed along the axis of the tropical wave on September 9, which further increased convective activity. The system was assessed with a high chance for tropical cyclone formation on September 10. Based on satellite intensity estimates, the National Hurricane Center declared the disturbance as Tropical Depression Fourteen at 1200 UTC on September 10, while the storm was about 885 miles (1,424 km) west of Cape Verde.
Although thunderstorm activity was initially minimal around the center of circulation, a convective band associated with the depression was becoming more organized. Late on September 10, convection began to increase slightly near the center, but because Dvorak intensity T-numbers were between 2.0 and 2.5, the depression was not upgraded to a tropical storm. However, dry air briefly caused showers and thunderstorms to decrease later that day. Initially, it headed just north of due west around the southern periphery of a large subtropical ridge. However, by September 11, the depression re-curved northwestward. Later that day, the depression began to regain deep convection. Geostationary satellite imagery and scatterometer data indicated that the depression strengthened into Tropical Storm Nadine at 0000 UTC on September 12.