What Lies Ahead for the 2014 Hurricane Season?

The 2014 season is poised to pick up where 2013 left off as being a quieter than average Atlantic Basin hurricane season.  The Atlantic Basin hurricane season averages 12 named tropical storms, 6 hurricanes and 3 major hurricanes.

A system is named a tropical storm when sustained winds around the storm center reach 39 mph and the tropical storm becomes a hurricane when sustained winds increase to 74 mph.  A hurricane becomes “major” when sustained winds around the center of the storm reach at least 111 mph, making it a Category 3 on the Saffir-Simpson Hurricane Intensity Scale (rankings go from 1 to 5).  

The 2013 hurricane season featured 13 tropical storms and 2 hurricanes.  For the first time since 1994, there were no major hurricanes in the Atlantic Ocean.  Not only were there fewer hurricanes than normal, the hurricanes that developed (i.e., Humberto and Ingrid) did not intensify significantly.  Scientists attribute the quiet hurricane season last year to a few factors.  There was significant wind shear – differing wind speeds and direction with altitude – in the Gulf of Mexico and northwestern Caribbean Sea.  For most of the 2013 season, there was also a plume of dry, dusty air that spilled off the west coast of Africa into the tropical Atlantic.  Tropical storms and hurricanes need calm winds and a moist atmosphere to develop and intensity, so the wind shear and dry air created a largely hostile environment in 2013. 

The Atlantic Basin hurricane season starts June 1 and runs through November 30, with the most active part of the season being from mid-August to mid-October when ocean temperatures are their warmest.  Led by scientists at the National Oceanic and Atmospheric Association (NOAA), the National Hurricane Center recently updated their forecast for the hurricane season.  They expect a near or slightly below average season with between 8 and 13 tropical storms, of which 3 and 6 will grow into hurricanes of which 1 to 2 will become major.  Meanwhile, a distinguished group of atmospheric scientists at Colorado State University, released their forecast for the 2014 hurricane season last month.  They expect 9 tropical storms to be named of which 3 will develop into hurricanes.

Such similar forecasts for the upcoming Atlantic hurricane season can be partially attributed to the expected return of El Nino during the summer and early fall.  “El Nino” refers to the periodic warming of the tropical eastern Pacific Ocean.  This warming creates changes in weather around the world, including the tropical Atlantic.  The presence of El Nino commonly leads to increased levels of wind shear along with cooler water temperatures in the tropical Atlantic.  Both of these factors inhibit tropical storm formation.  

Ironically, it does not matter how many tropical storms form, it’s where they develop and track that’s truly important.  For example, the 1992 hurricane season was a below average season in the Atlantic Ocean.  It began slowly with the first tropical storm not developing until mid-August.  However, that storm was the infamous Hurricane Andrew – only the third Category 5 hurricane on record to make landfall in the United States.  Hurricane Andrew was also the costliest natural disaster in U.S. history until Hurricane Katrina in 2005. 

This blog post was adapted from a story I wrote for wusa9.com.  So far the tropics look quiet – as they typically do in early June.