Hurricane Season Nearing a Close

 

Hurricane Iota, November 2020 (Source: NOAA)

The 2020 Atlantic hurricane season has been an epic one with a record number of named storms.  A total of 30 named tropical storms developed, of which 14 became hurricanes, including seven major hurricanes.  The 30 named storms surpassed the previous record of 28 from 2005.  However, there were 15 hurricanes in 2005 with seven major (Category 3 or higher) ones.

This season began early (before June 1) for a sixth consecutive year, with two named storms in May.  That’s unlike 2005 which didn’t see the first tropical storm until the second week of June.  The 2005 season didn’t end until the first week of January, when the final named storm (Tropical Storm Zeta) weakened on January 6.  The tropical Atlantic, including the Gulf of Mexico and Caribbean Sea, is fairly quiet now, so it remains to be seen whether or not the 2020 season will continue past its official end on November 30 as it did in 2005. 

Even if no more named storms develop, 2020 would have the distinction of seeing the highest number of tropical storms and hurricanes (12) make landfall in the United States.  This high number of landfalls was largely a function of where the bulk of this season’s tropical storms and hurricanes developed.  Many of them developed in the Gulf of Mexico/Caribbean Sea or off the southeast Coast of the United States – not far from the U.S. coastline.  By comparison, only eight named storms (five hurricanes and three tropical storms) directly impacted the United States in 2005.

While 2005 and 2020 will both finish with a nearly identical number of major hurricanes, the Atlantic had four Category 5 hurricanes in 2005, compared to only one this season.  That helped 2005 finish with the highest amount of Accumulated Cyclone Energy or “ACE” (a metric used to measure the energy used by a tropical cyclone during its lifetime) of any season since the satellite era began in 1966.  This season is currently in sixth place with 180 units of ACE.

Another key difference between this season and 2005 is how the majority of the named storms for the first half of the season were relatively weak.  The first major hurricane of 2020, Hurricane Laura, didn’t develop until late August.  By comparison, the 2005 season had two major hurricanes in July, including Hurricane Emily that became the earliest Atlantic Category 5 hurricane on July 16.  Only two of the first 25 named storms this season became major hurricanes (Laura, Teddy).  However, four of the last seven named storms have become major hurricanes. 

When Hurricane Iota reached Category 5 intensity on November 16, it became the latest in the season a Category 5 has developed in the Atlantic Ocean.  Iota was also the first Category 5 hurricane with a name from the Greek Alphabet and, along with Hurricane Eta, made 2020 the first November on record that the Atlantic had two major hurricanes.  Not only was Hurricane Iota the strongest hurricane of the season, but was the second strongest November hurricane in the Atlantic, overall, behind only the 1932 hurricane that made landfall in Cuba.  Its peak intensity was with 175 mph and a minimum central air pressure of 915 millibars (mb) compared to 160 mph / 917 mb for Iota.

It remains to be seen whether or not Hurricane Iota will be the final named storm of the 2020 Atlantic hurricane season.  But, this season will not finish as one of the costliest on record for the United States.  That’s despite the high number of landfalling systems, primarily because the majority of the storms that made landfall were not that strong unlike 2005 and other, more recent, seasons like 2017.