Hurricane Season 2017

Tropical Storm Arlene, April 2017  Source: NOAA

The busiest time of the six-month hurricane season is from August through September.  A busier than average hurricane season is forecasted by NOAA and the team of scientists at Colorado State University.  An average Atlantic hurricane season features 12 tropical storms, 6 hurricanes and 3 major hurricanes (Category 3 or higher on the Saffir-Simpson Hurricane Intensity Scale).  There have been 5 tropical storms so far this season.

The first and strongest named storm so far in 2017 was Tropical Storm Arlene, which had 60 mph sustained winds at peak intensity.  Arlene was the first Atlantic tropical storm to form during the month of April since 2003.  This past week, Emily was a short-lived tropical storm that brought appreciable rainfall to parts of central Florida.

The fact that no hurricanes have formed yet this season is not significant.  For example, 7 tropical storms formed before the first hurricane of the 2011 season (Irene) developed on August 22.  Some may recall that Irene was one of 7 hurricanes that formed during the very active 2011 season and it impacted the Mid-Atlantic Region.

All tropical storms and hurricanes are significant regardless of their intensity when they make landfall.  No major hurricane has made landfall anywhere in the United States since Wilma in October 2005.  While, several destructive and deadly hurricanes have impacted the United States since then (Ike in 2008, Irene in 2011 and Isaac in 2012), none were at Category 3/+ intensity when they made landfall.  Tropical Storm Allison in 2001 became the first and only tropical storm to have its name retired for being destructive and deadly. 

Colorado State University released its updated seasonal hurricane forecast this morning and they expect a total of 16 tropical storms, 8 hurricanes and 3 major hurricanes in the Atlantic Ocean.  NOAA will issue its early August update very soon.  One factor that scientists look at when issuing seasonal hurricane forecasts is the presence of El Nino or La Nina, which can influence sea surface temperatures and the amount of wind shear in the tropics.  

A busier than average hurricane season doesn’t necessarily mean the United States will be impacted.  The 2010 Atlantic hurricane season was one of the busiest on record with 19 tropical storms, 12 hurricanes and 5 major hurricanes, but the United States only saw minimal impacts.  Meanwhile, the 1992 hurricane season was quieter than average with only 7 named storms in the Atlantic Ocean.  However, Hurricane Andrew developed in 1992 and remains the last Category 5 hurricane to make landfall in the United States.