1. The Season Already Began
More than 40 days before the season's official start date, the first storm of the 2017 season developed in the northern Atlantic Ocean.
Tropical Storm Arlene was named April 20 and marked the first named storm to occur in that month since 2003. Arlene's formation began as Subtropical Depression One, which was designated on April 19. It then acquired full tropical characteristics about 24 hours later.
June 1 marks the official start of the season, but storms can form before that date. In fact, the last three years have featured these so-called preseason storms, including Tropical Storm Arlene (2017), Hurricane Alex (January 2016) and Tropical Storm Ana (May 2015).
2. 'Irma' Makes Its Debut on 2017 Named Storm List
The list of names being used in 2017 has one newcomer from when it was last used in 2011. This year's "I" storm will be Irma instead of the now-retired Irene used six years ago.
Hurricane and tropical storm name lists repeat every six years unless one is so destructive and/or deadly that a World Meteorological Organization committee votes to retire that name from future lists.
Irene first pounded the Bahamas and then made landfall in eastern North Carolina as a Category 1 hurricane on Aug. 27, 2011. It was at tropical-storm strength for its final two landfalls along the Northeast coast.
Inland rainfall flooding, particularly from New Jersey to New England, largely contributed to its $15.8 billion price tag.
Irene was responsible for 49 direct deaths during its lifespan: 41 in the United States, five in the Dominican Republic and three in Haiti.