Hurricane Season Arrives June 1

NOAA announced on April 19 that after months of analysis, Hurricane Michael was a Category 5 when it made landfall in the Florida panhandle last October.  That made it one of only four Category 5 hurricanes to make landfall in the United States and the first since Andrew in 1992.  Before Michael, the Florida panhandle had actually never had a hurricane stronger than a Category 3 make landfall.  

With Michael reclassified as a Category 5 hurricane that cemented the three-year period of 2016 - 2018 as one of most active periods in recent memory.  For the three-year period, the Atlantic Ocean averaged nearly 16 tropical storms of which 8 became hurricanes with 4 major hurricanes.  A hurricane becomes “major” when sustained winds around the center reach 111/+ mph making it a Category 3 storm on the Saffir-Simpson Hurricane Wind Scale.  Last year also became the third consecutive year that at least one Category 5 hurricane formed in the Atlantic Ocean Basin.  That follows Hurricane Matthew in 2016 and Hurricanes Irma and Maria in 2017 that all reached Category 5 intensity.  Despite weakening before making landfall, they were each destructive and deadly hurricanes. 

A weaker storm, such as a Category 1 or 2 hurricane, doesn’t necessarily mean it doesn’t have the potential to be a high impact storm.  Although Hurricane Florence weakened to Category 1 status before its landfall in North Carolina last September, it was a slow-moving system that caused widespread flooding well-inland.  Hurricane Matthew also weakened and was no longer a “major” hurricane when it made landfall in South Carolina in 2016.  Both names were subsequently retired by the World Meteorological Organization for being both destructive and deadly.

The only other time the Atlantic Ocean had Category 5 hurricanes in three consecutive seasons was 2003 – 2005.  While none of the hurricanes made landfall at Category 5 intensity, there were still multiple destructive and deadly hurricanes.  Hurricane Isabel in 2003 was the Atlantic’s first Category 5 hurricane since 1998.  Isabel ultimately made landfall in North Carolina as a Category 2 hurricane.  The 2005 hurricane season was the busiest Atlantic hurricane season on record with 28 named storms.  It also had a single season record of four Category 5 hurricanes (Emily, Katrina, Rita and Wilma).  Hurricane Wilma also set a record for strongest hurricane on record in the Atlantic Ocean Basin.

The three-year period of 2010 – 2012 had an average of 19 tropical storms, 10 hurricanes and 4 major hurricanes in the Atlantic Ocean, meaning a higher total number of named storms developed than between 2016 – 2018.  However, none reached Category 5 intensity.  Category 5 hurricanes only form under the rarest of circumstances with landfalls by Category 5 hurricanes rarer still.

Early indications are that the 2019 Atlantic hurricane season will be below average (12 tropical storms with 6 hurricanes and 3 major hurricanes) due to a weak episode of El Nino expected to last for much of the summer.  NOAA will release its official forecast for the hurricane season on May 23.