Talking Tropics in December

Although the hurricane season ended several weeks ago, this is a good time to discuss some follow up points from a busier than average 2016 season.  December is poised to join July as only the second month since May that hasn’t had a named tropical storm in the Atlantic Ocean Basin.  That’s remarkable considering how relatively quiet the last few hurricane seasons have been.

The final tropical storm or hurricane to develop in 2006 was November’s Hurricane Otto.  It made landfall in Nicaragua as a Category 2 hurricane on November 24.  In a touch of irony, Otto was also the final storm in the tropical east Pacific as it was one of the rare storms to cross Central America from the Atlantic and emerge in the eastern Pacific at tropical storm intensity.  Otto was also the latest hurricane to form in the Caribbean since Martha in 1969.

In a somewhat rare occurrence, tropical storms have formed in seven months of 2016 for the highest such total since 2007.  This season also saw the first Category 5 hurricane (Matthew) in the Atlantic Ocean since Felix in 2007.  Hurricane Matthew weakened considerably to Category 1 intensity before making landfall in South Carolina in October.  Matthew showed that hurricanes don’t have to be major to have significant impacts (similar to Ike in 2008 and Irene in 2011).  2005’s Wilma remains the last major (Category 3 or higher) hurricane to make landfall in the United States.

A total of 15 tropical storms, 7 hurricanes including 3 major hurricanes developed in the Atlantic in 2016.  The first storm of the season, Alex, was a very rare January hurricane.  The next storm, Bonnie, developed in late May.  Category 3 Hurricane Gaston was the Atlantic’s first major hurricane of the year when it developed in late August.  Florida had its first landfalling hurricane (Hermine) since 2005.  Hermine was the minimal hurricane that made landfall in the Florida panhandle in early September.  The first hurricane in more than a decade to impact Florida was a key talking point until Hurricane Matthew developed in late September.

The 2013 and 2014 hurricane seasons were quieter than average in the Atlantic Ocean Basin for a variety of reasons, most notably a largely inhospitable environmental for tropical development.  A major El Nino event developed in 2015 that created more favorable conditions in the tropical east Pacific (west of Mexico) that conversely led to less ideal conditions in the tropical Atlantic.  That episode of El Nino quickly dissipated in the late winter and spring leading to more favorable conditions this hurricane season.  And the result was the busiest hurricane season in the Atlantic Ocean since 2012.