A subtropical cyclone is a weather system that has some characteristics of both tropical and extratropical cyclones.
The 1972 Atlantic hurricane season was a significantly below average season, having only seven named storms, four fully tropical storms and three subtropical storms. It officially began on June 1, 1972, and lasted until November 30, 1972. These dates conventionally delimit the period of each year when most tropical cyclones form in the Atlantic basin. The first storm, Subtropical Storm Alpha, developed on May 23 off the Southeast United States and struck Florida, causing minor damage and two fatalities. Although several other tropical depressions developed, only Tropical Depression Five is known to have affected land.
The 1978 Atlantic hurricane season was a slightly above average hurricane season in terms of number of named storms. Eleven tropical cyclones were named in all, and five of these became hurricanes; two of the five became a major hurricane. This was also the last Atlantic hurricane season to use an all-female naming list. The season officially began on June 1, 1978, and ended on November 30, 1978. These dates, adopted by convention, denote the period in each year when most tropical cyclogenesis occurs in the Atlantic basin. However, the formation of subtropical or tropical cyclones is possible at any time of the year, as shown by the formation of an unnamed subtropical storm on January 18.
The 2007 Atlantic hurricane season was the first season since 2003 to feature tropical activity both before and after the official bounds of the season. There were an above-average number of named storms during the season – 15, however many storms were weak and short-lived. Despite the predominance of weak systems, this was the first season on record to feature more than one Category 5 landfalling hurricane. This would not happen again until 2017. It produced 17 tropical cyclones, 15 tropical storms, six hurricanes, and two major hurricanes. It officially started on June 1 and ended on November 30, dates which conventionally delimit the period during which most tropical cyclones form in the Atlantic Ocean, although as shown by Subtropical Storm Andrea and Tropical Storm Olga in early May and early December, respectively, the formation of tropical cyclones is possible at any time of the year. The first system, Subtropical Storm Andrea, developed on May 9, while the last storm, Tropical Storm Olga, dissipated on December 13. The most intense hurricane, Dean, was, at the time, the third most intense landfalling Atlantic storm on record. It was the second on record in which an Atlantic hurricane, Felix, and an eastern Pacific hurricane, Henriette, made landfall on the same day. September had a then record-tying eight storms, until it was surpassed in 2020. However, the strengths and durations of most of the storms were low.
Subtropical Storm Andrea was the first named storm to form in May in the Atlantic Ocean in 26 years. Andrea caused large waves and tropical-storm force winds along the southeast coast of the United States. The first named storm and the first subtropical cyclone of the 2007 Atlantic hurricane season, Andrea developed out of a non-tropical low on May 9 about 150 miles (240 km) northeast of Daytona Beach, Florida, three weeks before the official start of the season. After encountering dry air and strong vertical wind shear, Andrea weakened to a subtropical depression on May 10 while remaining nearly stationary, and the National Hurricane Center discontinued advisories early on May 11. Andrea's remnant was subsequently absorbed into another extratropical storm on May 14. Andrea was the first pre-season storm to develop since Tropical Storm Ana in April 2003. Additionally, the storm was the first Atlantic named storm in May since Tropical Storm Arlene in 1981.
The 2007 Atlantic hurricane season was an event in the annual tropical cyclone season in the north Atlantic Ocean. A near average Atlantic hurricane season, September had a record-tying eight storms, although the strength and duration of most of the storms was low. Also, for only the second time in recorded history, an Atlantic hurricane, Felix, and an eastern Pacific hurricane, Henriette, made landfall on the same day.
The 1974 Atlantic hurricane season was a cycle of the annual tropical cyclone season in the Atlantic Ocean in the Northern Hemisphere. There was near-average activity during the season, which officially began on June 1, 1974 and ended on November 30, 1974. These dates, adopted by convention, historically describe the period in each year when most tropical systems form. The first system of the season, Tropical Depression One, formed on June 22. The final system of the season, Tropical Depression Seventeen, dissipated on November 11.
The 2013 Atlantic hurricane season was a well below average Atlantic hurricane season in terms of the number of hurricanes. It was the first since 1994 with no major hurricanes, Category 3 or higher on the Saffir–Simpson scale, and the first in the satellite era where no hurricanes reached Category 2 strength. Altogether, the season produced 15 tropical cyclones, of which all but one became a named storm. The season officially began on June 1, 2013, and ended on November 30, 2013. These dates historically describe the period in each year when most tropical cyclogenesis occurs in the North Atlantic and are adopted by convention. The first storm of the season, Andrea, developed on June 5, while the last, an unnamed subtropical storm, dissipated on December 7. Throughout the year, only two storms, Humberto and Ingrid, reached hurricane strength; this was the lowest seasonal total since 1982.
The 2013 Atlantic hurricane season was an event in the annual hurricane season in the north Atlantic Ocean. It featured below-average tropical cyclone activity, with the fewest hurricanes since the 1982 season. The season officially began on June 1, 2013 and ended on November 30, 2013. These dates, adopted by convention, historically delimit the period in each year when most tropical systems form. The season's first storm, Tropical Storm Andrea formed on June 5, and its final storm, an unnamed subtropical storm, dissipated on December 7. Altogether, there were 13 named tropical storms during the season. Two of which attained hurricane strength, but neither intensified into a major hurricane, the first such occurrence since the 1994 season.
