Does El Nino impact Atlantic Ocean Hurricanes?

Hurricane Gonzalo, October 2014  Source: NASA

If you’re one of those people thinking this year’s hurricane season has been quiet, than you would be correct.  Although a tropical storm developed in May (Ana) – before the season officially began – it has been a relatively quiet season.  In fact, NOAA recently issued the August update to its seasonal hurricane forecast and concluded the 2015 hurricane season should remain quieter than average. 

That’s largely because of the developing El Nino event that is characterized by warmer sea surface temperatures in the central and eastern equatorial Pacific Ocean.  This situation affects global weather patterns and helps make conditions more favorable for tropical storm formation off the west coast of Mexico.  However, El Nino also tends to make conditions in the tropical Atlantic Ocean less favorable for tropical storms.

NOAA’s early August update for the 2015 Atlantic hurricane season predicts a total of 6 to 10 tropical storms, of which 1 to 4 will become hurricanes with up to one “major” hurricane – Category 3 or higher on the Saffir-Simpson Hurricane Intensity Scale.  So far this season, there have been only three short-lived tropical storms.  No hurricanes have developed anywhere in the Atlantic Ocean Basin (that includes the Caribbean Sea and Gulf of Mexico) since Gonzalo last October.

People tend to forget that a quieter than average hurricane season doesn’t necessarily mean that it can’t or won’t feature a high impact storm.  For example, the 1992 season was quieter than average (concurrent with a moderate El Nino event) and featured only 7 tropical storms, 4 hurricanes and 1 major hurricane.  However, many will remember that “major” storm as Hurricane Andrew.  In fact, Andrew was named as a tropical storm on this date 23 years ago and went on to become only the third Category 5 hurricane on record to make landfall in the United States.

Although the busiest part of the hurricane season is just getting underway (with September averaging the highest number of tropical storms and hurricanes), every expectation is for this season to finish up being the third consecutive quieter than average one.  Meteorologists at the National Hurricane Center will track any developments in the tropics while my colleagues and I on the WUSA9 weather team will continue to monitor any tropical storms that form should they track toward the U.S. East Coast.