Gulf of Mexico May Yield Tropical System Prior to September's End

By Alex Sosnowski, AccuWeather.com Senior Meteorologist

September 25,2015; 10:30PM,EDT

 

 

A tropical system may form over the Gulf of Mexico and deliver heavy rain to part of the Deep South before the end of September.
How much rain falls and exactly where along the Gulf coast next week will depend on the exact track and strength of a system that has not yet formed.
Current indications favor the bulk of the rain to target the zone from Louisiana to northern Florida. However, since the storm is several days away and the track of the system is still uncertain, the heavy rain area could shift farther west or east.

If a tropical system was to take shape, then gusty winds, building seas, rough surf, minor coastal flooding and severe thunderstorms may also become concerns for petroleum and coastal interests.
The zone being monitored is an area of disturbed weather with showers and thunderstorms near Central America. The region may give birth to one or more tropical systems over the next several days.

One system may develop on the Pacific side, while a second system could gradually take shape on the Atlantic side, near or north of Mexico's Yucatan Peninsula.
According to AccuWeather Hurricane Expert Dan Kottlowski, "The broad area of disturbed weather on the Atlantic side will slowly move northward through next week."
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Water temperatures are in the 80s F over much of the Gulf of Mexico, which is warm enough to support tropical development.
The same condition that has limited tropical development in the Atlantic much of this season will still be a factor in the Gulf of Mexico next week.
"Strong wind shear over the Gulf of Mexico will limit development," Kottlowski said.
Wind shear is the changing of wind direction and speed at various levels of the atmosphere. In order for tropical systems to form, strengthen or maintain strength, wind shear must be low.
As a result, the odds are against the system from becoming very strong, despite the warm waters.
"Because of the persistent wind shear, the chance of a major hurricane impacting the United States for the remainder of 2015 is very low." Kottlowski said. "Research from the Colorado State University shows that since 1878, no major hurricanes have impacted the U.S. in October and November during El Niño years."

El Niño is associated with warmer-than-average sea surface temperatures in the tropical Pacific Ocean. While this warm water and correspondingly rising air in part of the Pacific leads to stronger and more frequent tropical storms in the same basin, it generally translates to less storms in the tropical Atlantic.
"We have seen features like this develop into tropical depressions and tropical storms, so all interests around the Gulf of Mexico should monitor the evolution of this system," Kottlowski said.
Regardless of significant tropical development or not, the weather pattern will deliver a dose of drenching rain to the Gulf Coast region next week.
In the absence of flooding rain, downpours would not be a terrible thing for portions of the upper Gulf Coast. Places from the Florida Panhandle to Louisiana are experiencing abnormally dry to severe drought conditions.
In the Atlantic basin thus far, there have been two hurricanes, including one major hurricane named Danny, during 2015. There have been eight tropical storms with Ana and Bill making landfall in the U.S. In May, AccuWeather predicted eight tropical storms, four hurricanes, one major hurricane and two to three landfalls in the U.S.