Hurricane Season Comes to a Close

2015 Atlantic Hurricane Season  (Source: NOAA)

The 2015 hurricane season in the Atlantic Ocean ends on Monday.  This season’s forecast for a near average season proved to be a good one.  There were a total of 11 tropical storms, 4 hurricanes and 2 major hurricanes compared to the seasonal average of 10, 6 and 2 respectively. 

The first storm of the season, Tropical Storm Ana, formed on May 8, while the final storm was Hurricane Kate which dissipated on November 12.  The strongest storm of the season was Hurricane Joaquin – at peak intensity, Joaquin was a borderline Category 4 – Category 5 hurricane (with sustained winds of 155 mph on October 3).  As some will recall, Joaquin tragically caused dozens of fatalities and significant damage in the Bahamas.

Although Joaquin was the strongest Atlantic hurricane since 2010, the Atlantic has had its third consecutive near or quieter than average season.  That’s especially significant following the 17-year period (1995 – 2012) that the Atlantic Ocean saw above average hurricane activity.  According to the National Hurricane Center, no Category 5 hurricane has formed in the Atlantic since 2007.  No “major” (Category 3 or higher) hurricane has made landfall in the United States since October 2005. 

Climate scientists and tropical meteorologists attribute the largely quiet 2015 season to the emergence of a strong El Nino in the eastern Pacific Ocean.  That helped created more favorable conditions in the tropical East Pacific (off the west coast of Mexico), where there was an above average hurricane season.  Although hurricane season there ended November 15, Sandra was named a tropical storm on November 23 and became a Category 4 hurricane – the latest in the season a hurricane has reached that intensity. 

There have been non-El Nino years when the circumstances were flipped and the Atlantic Ocean saw more tropical activity than the eastern Pacific Ocean.  Such was the case in 1995, which was one of the busiest hurricane seasons on record in the Atlantic Ocean (with 19 tropical storms, 11 hurricanes and 5 major hurricanes).  Meanwhile, only 10 tropical storms, 7 hurricanes and 3 major hurricanes formed that year in the eastern Pacific Ocean – far below the annual average.