July Hurricanes Like Barry

Tropical Storm Barry Getting Stronger, July 12, 2019 (Source: NOAA)

“Barry” became a minimal hurricane shortly before its landfall in south central Louisiana earlier today.  Sustained winds around its center were 75 mph, making it a Category 1 hurricane on the Saffir-Simpson Hurricane Wind Scale.  The difference in impacts between a strong tropical storm and a minimal hurricane like Barry are rather insignificant.  

A tropical storm becomes a hurricane when sustained winds around the center of circulation reach 74 mph.  In systems like this, the major impact is flash flooding that results from a copious amount of rainfall, often 10” to 15”.  Rainfall totals from tropical systems largely depend on how quickly the system moves.  

Barry’s landfall as a Category 1 hurricane set a series of benchmarks.  Barry became the first July hurricane to make landfall in Louisiana since Cindy in 2005.  It was also the first hurricane to make landfall in the United States during the month of July since Arthur in 2014.  Overall, the last hurricane to make landfall in the state of Louisiana in any month was Nate in October 2017. 

In addition to flooding, Barry is generating isolated reports of severe weather.  Landfalling tropical systems often spawn tornadoes as the storm’s circulation interacts with a given land mass.  Fortunately, the majority of tornadoes that occur under these circumstances are relatively weak.  However, they are dangerous since sight of them is quite frequently obstructed by heavy rainfall.  It will take some time to assess the final impacts of Barry, since the destruction of landfalling tropical systems often extends well-inland.

Barry and Cindy were both minimal Category 1 hurricanes at their respective times of landfall in Louisiana.  However, Cindy made landfall earlier in the season than Barry, having come ashore on July 5, 2005.  Other significant hurricanes have developed in July.  Hurricane Dennis was a powerful Category 4 hurricane with sustained winds of 150 mph while over the Gulf of Mexico in 2005.  Fortunately, it weakened prior to making landfall in the Florida panhandle as a Category 3. 

For a short time, Dennis was the strongest July hurricane on record in the Atlantic Ocean Basin (the Caribbean Sea and Gulf of Mexico).  That was before Hurricane Emily briefly became a Category 5 hurricane on July 16, 2005.  It had sustained winds of 160 mph at peak intensity southwest of Jamaica.  Although Emily didn’t make landfall in the United States as Cindy and Dennis did, its impact was felt in the Caribbean Sea, Yucatan Peninsula of Mexico as well as mainland Mexico.

Hurricane Barry is the second named storm of 2019 and the Atlantic’s first hurricane of the season.  NOAA scientists are expecting an average hurricane season this year.  An average season has 12 tropical storms, of which 6 become hurricanes with 3 major hurricanes.  A “major” hurricane has sustained winds of at least 111 mph, making it a Category 3.