NOAA’s Hurricane Update

The Atlantic Ocean Basin also includes the Gulf of Mexico and Caribbean Sea

NOAA just issued an August update to its seasonal hurricane forecast.  When the season began on June 1, NOAA cited El Nino conditions as a primary reason for near to below average tropical activity in 2019 across the tropical Atlantic.  However, El Niño has dissipated and that opened the door to NOAA’s updated hurricane forecast.

In early June NOAA was expecting a near average Atlantic hurricane season (12 tropical storms, six hurricanes and two major hurricanes).  That was consistent with the El Nino conditions at the time.  An episode of El Nino often contributes to below average sea surface temperatures and above average levels of wind shear in the tropical Atlantic.  Both tend to preclude tropical development.

The season has gotten off to a quiet start with only two named storms, including a minimal hurricane.  However, June and July are normally quiet months in the tropical Atlantic.  NOAA’s updated hurricane forecast calls for a total of 10 – 17 tropical storms and 5 – 9 hurricanes, 2 – 4 of which become major hurricanes (Category 3 or greater with sustained winds of at least 111 mph).

Scientists at Colorado State University also tweaked their forecast and are expecting a seasonal total of 14 tropical storms, seven hurricanes and two major hurricanes.  Aside from El Nino conditions dissipating, there has been another key weather headline in the tropical Atlantic.  Atmospheric winds between 5,000 feet and 20,000 feet blew large plumes of dust into the tropical Atlantic from western Africa to west of the Cape Verde Islands.  That helped create some unusually dry and stable air in the same area that tropical storms develop during the height of the season.

There have been active hurricane seasons that got off to slow starts, as this season has.  The 2004 season comes to mind, which had 15 tropical storms, nine hurricanes and six major hurricanes after not seeing the first named storm of the season until August 1.  The overall number of tropical storms and hurricanes that develop is less important than where they develop.  For example, the 1992 Atlantic hurricane season featured only one major hurricane.  But that was Hurricane Andrew which remains one of the costliest and most intense hurricanes to ever impact the United States.  

The National Hurricane Center doesn’t expect any tropical development in the next five days.  The next named storm in the Atlantic Ocean will be “Chantal.”