A Sneak Peak of Hurricane Season

 

Hurricane Lorenzo, September 2019  (Source: NOAA)

Although the Atlantic hurricane season doesn’t officially get underway until June 1, a new NOAA report contains a big clue as to what kind of season could occur in 2022.  NOAA said on March 10, there was a 40% - 50% chance La Nina conditions will continue into the fall.  That would have significant repercussions for the tropical Atlantic.

La Nina helps create ideal conditions for tropical storm formation because it is characterized by above average sea surface temperatures and a below average amount of wind shear (i.e., winds that differ in direction with altitude).  The busiest Atlantic hurricane seasons often occur during episodes of La Nina.  Even ENSO neutral conditions (neither El Nino or La Nina) tend to feature more favorable conditions in the tropical Atlantic then El Nino conditions.  The tropical Atlantic sees below average activity during El Nino events (circa 1992, 1997, and 2015).

While the presence of La Nina or El Nino are major drivers of tropical activity, there are other factors to consider as well.  The presence of atmospheric dust that sometimes travels west from central Africa into the tropical Atlantic can impact tropical storm formation.  The presence of above or below average temperatures in the Atlantic Ocean Basin are also important factors to consider.  The Atlantic Ocean Basin includes the Gulf of Mexico and Caribbean Sea.

Every Atlantic hurricane season since 2016 has been busier than average.  However, the overall number of tropical storms and hurricanes is less important than where they develop and track.  For example, this summer will be the 30^th anniversary of Hurricane Andrew, which remains one of the strongest and costliest hurricanes to ever make landfall in the United States.  Ironically, it was the only major hurricane in what was an otherwise quieter than average Atlantic hurricane season.  By comparison, the 2010 Atlantic hurricane season was very active during a strong episode of La Nina.  Fortunately, the United States didn’t see any direct impacts from the 12 hurricanes that developed in 2010.

Another trend that bears watching this spring is whether or not 2022 becomes the eighth consecutive year at least one named storm develops before the official June 1 start of the season.  While having named storms develop early often foreshadows an active hurricane season, that isn’t always the case.  For example, a subtropical storm developed in April 1992, which was a quieter than average season.  Distinguished scientists at NOAA and Colorado State University will issue their forecasts for the upcoming Atlantic hurricane season later this spring.