Hurricane Eta Breaks Records

 

Hurricane Eta near peak intensity, November 2, 2020 (Source: NOAA)

Earlier this week Hurricane Eta reached its peak intensity as a Category 4 storm with sustained winds of 150 mph in the western Caribbean Sea.  Its minimum central air pressure fell to an unusually low level at 923 millibars (mb) – more commonly found in a Category 5 hurricane.  Eta subsequently made landfall as a Category 4 hurricane in Nicaragua on November 3.

Eta was also the 28^th named storm of the 2020 Atlantic hurricane season and that tied this season with the 2005 record for most active season on record.  While this season hasn’t had as many major hurricanes as 2005, five vs. seven, there have been more U.S. landfalls by tropical systems this year.  The 11 named storms (tropical storms and hurricanes combined) that made landfall in the United States in 2020 broke the previous record of nine set in 1916.  Hurricane Eta also became the strongest Atlantic hurricane with a Greek name.  The previous record holder was Hurricane Delta earlier this season that was also a Category 4. 

Category 4 hurricanes in November are rare.  Including Hurricane Eta, there have been only five with the last one being Paloma in 2008.  Eta is also the second strongest Atlantic hurricane on record during the month of November, behind only a Category 5 storm that made landfall in Cuba in 1932.  Because of where Hurricane Eta developed and quickly intensified, there have been comparisons between it and Hurricane Mitch from October 1998.  Mitch reached Category 5 intensity, but weakened considerably before its landfall in Honduras.

Mitch and Eta both caused devastating flooding in Central America.  Mitch made landfall in southwest Florida as a tropical storm on November 5, 1998, before it quickly raced out into the Atlantic Ocean.  Eta’s track is forecast to be similar to Mitch’s in that it could track toward southwest Florida. 

While Mitch became the strongest Atlantic hurricane since Gilbert 10 years earlier, Eta has another impressive distinction.  Its minimum central air pressure of 923 mb made Hurricane Eta the third strongest Atlantic hurricane on record not to achieve Category 5 intensity.  Only 1995’s Hurricane Opal with a peak intensity of 150 mph and minimum air pressure of 916 mb and 1985’s Hurricane Gloria (145 mph/919 mb) had lower air pressures.  Air pressure is widely considered to be a more accurate measure of hurricane intensity than wind speed.  That’s because there’s often a lag time between a significant rise or fall in air pressure in a hurricane and a commensurate rise or decrease in sustained winds. 

Hurricane Eta has weakened to a tropical depression over Central America.  However, the National Hurricane Center expects it to regain tropical storm intensity once it reemerges over the western Caribbean Sea.  Prior to Eta, the last major Atlantic hurricane (Category 3 or higher) to develop during the month of November was Hurricane Otto in 2016.