Hurricane Ophelia, October 2017      Source: NOAA

September is commonly the most active month of the hurricane season in the Atlantic Ocean Basin, which includes the Gulf of Mexico and Caribbean Sea.  The tropics often get busier as the month of August wears on and conditions get more favorable for tropical development.  However, that hasn’t been the case in 2018 and there hasn’t been an Atlantic hurricane since Chris dissipated on July 12.

The month of August has been very quiet in the Atlantic Ocean this season with only two weak and short-lived tropical storms.  There have been three prior Augusts since 2000 with no hurricanes, according to NOAA records, with the most recent being in 2013.  This illustrates that while uncommon, it’s not unheard of for the Atlantic Ocean to go without a hurricane in August.  An average hurricane season in the Atlantic has 12 tropical storms, of which 6 becomes hurricanes and 3 of those become “major” Category 3/+ storms.

The 2013 Atlantic hurricane season was quieter than average with 14 tropical storms and only 2 minimal hurricanes, but none in August.  While the 2001 Atlantic hurricane season was busier than average, none of the three Atlantic tropical storms in August 2001 became hurricanes.  Likewise, August 2002 was a relatively quiet month with only two tropical storms but September 2002 was quite active with seven tropical storms and three hurricanes.

 

These examples illustrate that a hurricane season can be busier than average, overall, despite having a quiet August.  Also, having a quiet month of August in the tropical Atlantic does not in any way foreshadow a quieter than average September, traditionally the busiest month of the hurricane season.  There have been a number of times where an otherwise active season had a slow stretch of weather in the tropics.  According to a tweet from hurricane expert Dr. Philip Klotzbach, of Colorado State University, “…1961 had zero Atlantic named storms in August. September 1961 was very active with four major #hurricanes forming.” 

 

The 2018 Atlantic hurricane season is far from over, despite the relatively quiet last six weeks.  It’s important to remember that it only takes one storm to make it a damaging and/or deadly hurricane season.  For example, only one major hurricane formed in 1992, but that was catastrophic Hurricane Andrew.  The strongest Atlantic storm so far this year was Category 2 Hurricane Chris.  No major hurricane has developed in the Atlantic Ocean since Hurricane Ophelia last October.