Hurricane Season Update

Hurricane Lorenzo near peak intensity  (Source: NOAA)

If the 2019 Atlantic hurricane season were to end today, then it would essentially finish with an average number of named storms.  There have already been 12 tropical storms of which 5 became hurricanes, including three major hurricanes.  Although June and July were predictably quiet months in the tropical Atlantic, the first named storm of the season (Andrea) developed before June 1 for a record fifth consecutive year.

NOAA was expecting a near average hurricane season when it began on June 1.  However, once the weak episode of El Nino dissipated early in the summer NOAA revised its forecast in early August.  El Nino conditions tend to correlate with less favorable conditions for tropical development in the Atlantic Ocean Basin.  So it wasn’t a surprise than NOAA’s updated forecast called for a slightly busier than average hurricane season.

The two most significant Atlantic storms of the season to this point have been Hurricanes Dorian and Lorenzo.  Both achieved Category 5 intensity and that made 2019 the fourth consecutive year one has developed in the Atlantic Ocean.  The previous record for most consecutive seasons with a Category 5 hurricane was three, from 2003 – 2005.  Although Dorian devastated parts of the Bahamas at peak intensity, it weakened considerably before impacting the southeastern U.S. coastline.  Nevertheless, Dorian still had significant impacts in the United States.

While not a threat to the United States, Lorenzo remains a noteworthy storm for becoming the easternmost point an Atlantic hurricane has reached Category 5 intensity (45°W).  It also put this season in relatively rare company as one of a total of only seven seasons with at least two Category 5 Atlantic hurricanes (1932, 1933, 1961, 2005, 2007 and 2017).  This is the fourth time “Lorenzo” has been a named storm in the Atlantic Ocean Basin and the 2019 version is easily the most intense.

Tropical storms and hurricanes only develop when atmospheric and environmental conditions are favorable.  September is the busiest month of the Atlantic hurricane season so it’s common to see hurricanes develop.  October is also an active month of the hurricane season that’s seen a number of significant storms such as Hurricanes Mitch, Wilma and Matthew.  While all three reached Category 5 status, none of them impacted the United States at that intensity.  It remains to be seen how busy the rest of the Atlantic hurricane season will be before the season ends November 30.