Atlantic hurricane season 2016: What to expect in July
The Weather Channel analyzes what to expect in the way of hurricanes during July. While July is not the most active hurricane month in the Atlantic, Hurricane Emily — a Category V storm that devastated Cancun and Cozumel — was only one of several hurricanes unleashed in the disastrous month of July in 2005.
Atlantic basin hurricane and tropical storm development areas begin to spread east into the Atlantic Ocean in July, instead of being concentrated in the Gulf of Mexico, Caribbean Sea and close to the coast of the southeastern U.S.
The record-smashing 2005 hurricane season was very active in July.
Following the landfall of Hurricane Cindy in southeast Louisiana, Hurricane Dennis was, at the time, the strongest July Atlantic Basin hurricane on record, before landfalling in the Florida Panhandle.
Incredibly, just six days after Dennis made landfall, Hurricane Emily became the only Category 5 July hurricane of record in the Atlantic Basin, churning in the Caribbean Sea before striking Cancun and Cozumel, Mexico. Five named storms formed in July 2005.
Tropical storm (red) and hurricane (white) frequency by month in the Atlantic Basin.
From 1950-2015, 63 named storms formed in July, averaging out to about one named storm in July each year. Incidentally, the Atlantic season’s first named storm will have formed by the second week of July in a typical season.
Of those named storms from 1950-2015, 27 strengthened to hurricanes, for an average of one July hurricane every two to three years.
Major hurricanes, Category 3 or stronger on the Saffir-Simpson Hurricane Wind Scale, in July are rare. Only five major hurricanes have flared during the hurricane season’s second month since 1950.
The month of July is a month of transition. Formation areas spread east to include more of the Atlantic Ocean to the east of the Lesser Antilles.
“The tropical waves coming off of western Africa every 2-4 days are a little better defined than in June,” says Dr. Rick Knabb, director of the National Hurricane Center and former hurricane expert at The Weather Channel. “That’s one reason why we start to look farther east for development in July.”
Typical origin and tracks of July tropical cyclones in the Atlantic Basin.
That said, the primary season for long-track tropical cyclones from the eastern Atlantic, known as “Cape Verde” storms, is in August and September.
The Gulf of Mexico remains somewhat active in July, though the western Caribbean Sea steps down a bit.
Bryan Norcross, senior hurricane specialist at The Weather Channel, says two factors limit the number of July Atlantic tropical cyclones.
“Cold fronts, one of the ‘seeds’ of a tropical cyclone, are much less likely to reach the tropics in July versus June. At the same time, water temperatures have not yet reached their peak.”
Development can also occur from north of Hispanola to north of the Bahamas. Those storms can either linger off the East Coast, churning up high surf leading to beach erosion and rip currents, curl or recurve harmlessly out into the open Atlantic, or in more rare cases, landfall along parts of the East Coast.
These are all averages. Not every July follows this perfect script.
Recent July Notable Storms
The last three years have seen at least one named storm in July. Whether this July will be active remains to be seen, however there have already been four named storms in 2016 through the end of June.
Named storm origin points in July.
In 2015, one tropical cyclone formed in the Atlantic basin during July, Tropical Storm Claudette. Claudette formed east-northeast of Cape Hatteras, North Carolina on Monday, July 13 and became post-tropical late Tuesday, July 14 before reaching Newfoundland. Gusty winds and rain were experienced in eastern Nova Scotia and Newfoundland.
Over the Fourth of July holiday in 2014, Hurricane Arthur raked eastern North Carolina and the Outer Banks with storm surge flooding and strong winds.
Hurricane Alex made landfall in July 2010 in northern Mexico, wringing out torrential, flooding rain in the Rio Grande Valley and Monterrey, Mexico. In 2011, we had three named storms form in the Atlantic basin during July.
The transition to formation areas in the central and eastern Atlantic mentioned earlier was illustrated in one of the most extreme examples in 2008.
On July 3, 2008, Tropical Storm Bertha became the farthest east named storm to form in the Atlantic Basin so early in the season in the satellite era. Bertha went on to become the earliest-in-season hurricane farthest east in the Atlantic (at about 50W longitude) and went on to become the longest-lived July named storm on record, lasting 17 days in the open waters of the Atlantic Ocean.
Also in July 2008, Category 2 Hurricane Dolly made landfall in southern Texas.
On the other hand, there have been plenty of Julys without a named storm. Three consecutive Julys (1999-2001) were devoid of even a single named storm. July 2012 was also inactive with zero named storms.