Hurricane Irma Slams into Florida, Weakens and Shakes Up the Southeast

Hurricane Irma north of Cuba approaching Florida  (Source: NASA)

Hurricane Irma made landfall in the Florida Keys as a Category 4 hurricane on Sunday, September 10, with sustained winds of 130 mph and a minimum central air pressure of 929 millibars (mb).  Irma tied for the 7^th strongest hurricane to make landfall in the United States due to the air pressure recorded.  It’s also the lowest pressure in a landfalling hurricane since Katrina (920 mb) in 2005 and the lowest pressure in a Florida hurricane since Andrew in 1992 (922 mb). 

Irma made a second landfall in Florida as a Category 3 hurricane (115 mph sustained winds, 940 mb minimum central pressure) on Marco Island, Florida.  It was one of the most significant hurricanes in that part of Florida since Hurricane Donna in 1960.  Hurricane Irma came barely two weeks after Hurricane Harvey made landfall in Texas.  This is the first season on record to have two Category 4 hurricanes make landfall in the United States, according to the National Hurricane Center.  

The World Meteorological Organization will likely retire the names “Harvey” and “Irma” when this hurricane season ends since both storms have been so damaging and deadly.  The last time consecutive names were retired was in 2005 (Rita, Stan).  While Hurricane Harvey brought unprecedented flooding to parts of Texas and Louisiana, Irma left a trail of devastation across parts of the Caribbean, Cuba and the Bahamas before it came ashore in Florida.  

Irma was also a Category 5 hurricane for a total of 78 hours, which that ties it with a 1932 hurricane for longest lasting Category 5 storm in the Atlantic Ocean Basin.  Irma was also a Category 5 hurricane for 3 consecutive days - a new Atlantic record.  Hurricane Irma was the first Category 5 hurricane to make landfall in Cuba since 1924.  In the United States, Irma was the first Category 4 hurricane to make landfall in Florida since Charley in 2004, and Florida’s first major hurricane since Wilma in 2005.  

While the storm surge associated with any hurricane is extremely dangerous and requires proper preparation, people often don’t realize that the effects of a hurricane are felt well inland.  For example, the city of Atlanta, Georgia, is now under a tropical storm warning for the first time as Irma weakens and heads north.  That underscores the need for evacuations in areas well inland that aren’t subject to storm surge.  Unlike major Hurricanes Charley and Andrew, Irma has been a much larger storm that is affecting more people and property. 

Concurrent recoveries from hurricanes as significant as Harvey and Irma will require the coordinated efforts of FEMA, state and local governments, as well as charities like the American Red Cross and the Salvation Army.  It’s important for everyone who evacuated from Hurricane Irma to not head home until local authorities confirm it’s safe to do so.  That may take several days or weeks in some cases.  This underscores the need for careful advance planning and heeding the advice of local authorities.