An Early Start to the Hurricane Season ?

Hurricane Alex, January 2016  (Source: NOAA)

The National Hurricane Center is watching an area of disturbed weather east of the Bahamas.  That’s where a tropical disturbance as a 70% chance of becoming the Atlantic’s first tropical storm of 2019 according to NOAA.  An Air Force Reserve reconnaissance aircraft is scheduled to investigate the disturbance later today.

Although hurricane season doesn’t official begin in the Atlantic Ocean until June 1, having a named storm develop early has become a regular occurrence in recent years.  At least one named storm has developed in the Atlantic in each of the last four years and in five of the last seven since 2012.  A system becomes a “tropical storm” and is given a name when the sustained winds around its center reach 39 mph.  If sustained winds reach 74 mph, then the tropical storm becomes a hurricane.

On occasion, a named storm has characteristics of both a tropical system and a non-tropical area of low pressure.  Under such circumstances, the system is classified as a “subtropical storm.”  That’s what happened with Tropical Storm Alberto last May, which began as a subtropical storm in the Gulf of Mexico.  However, it eventually became a fully tropical storm before it made landfall. 

When “Alberto” developed last May, it was the fourth consecutive year that a named storm formed prior to the official start of the hurricane season.  That tied the previous record for most consecutive years with a tropical storm prior to June 1 was three (1951 – 1954).  There have been four other instances where a tropical storm has developed prior to June 1 in consecutive years.  

In January 2016, Hurricane Alex developed south of the Azores and was the first Atlantic hurricane during the month of January since Alice in 1955.  Some may wonder if having a named storm prior to the official start of hurricane season is a reliable indicator of whether or not a given season will be an active one.  Quite simply, it isn’t.  That’s because tropical storms and hurricanes are complex systems that require a series of conditions to develop.  And if conditions are favorable for a tropical storm to develop prior to June 1, then that isn’t a guarantee that conditions will remain favorable for an active hurricane season as a whole.

The 1992 Atlantic hurricane season was a quieter than average season with only seven named storms.  However, a subtropical storm developed in April 1992.  According to the National Hurricane Center, 1992 was the first time since 1981 that a tropical or subtropical storm developed in the Atlantic Ocean Basin (that also includes the Gulf of Mexico and Caribbean Sea).  Eleven years passed before another storm developed in the Atlantic prior to June 1 when Tropical Storm Ana was named in April 2003.  Unlike the 1992 season, Ana was the first storm of what became an active 2003 Atlantic hurricane season.  The first named storm of 2019 will be given the name “Andrea.”