Fox News Weather Center

Atlantic Gives Birth to Tropical Depression Four

An area of disturbed weather in the south-central Atlantic has become tropical depression four.

The system moved westward across Africa during the first part of August.

According to AccuWeather Meteorologist Jordan Root, "Showers and thunderstorms continue to spiral around an area of circulation and organization seems to be increasing as this feature moves through favorable conditions during the middle days of this week."

When a closed circulation near the sea surface has been confirmed, a tropical depression is born. When sustained winds around the circulation reach 39 mph, a tropical depression is upgraded to a tropical storm.

The system is currently almost half way between the Cape Verde Islands and the Windward Islands just north of the Equator and is in a zone where winds aloft are light.

Strong winds aloft (wind shear) can prevent a tropical system from developing or cause an organized tropical system to weaken.

According to AccuWeather Meteorologist Evan Duffey, wind shear has been strong over the Caribbean during much of hurricane season thus far.

"The most likely time for the system to strengthen is through Thursday, since beyond this point wind shear is likely to increase as the system approaches and later moves into the Caribbean," Duffey said.

Should the system advance beyond the tropical depression stage it would gather the name Danny, following Ana, Bill and Claudette.

Much of the islands in the Caribbean Sea are in drought and would trade the inconvenience and hazards that a tropical storm would bring for rainfall. Even a poorly organized tropical depression or storm could bring an uptick in drenching showers and thunderstorms, should the system track close by.

The exact track of the system beyond several days is questionable at this point. A track across the Windward or southern Leeward islands around Monday, and then into the Caribbean later next week seems most likely. However, a curve to the northwest is also a possibility.

Another significant area of disturbed weather is forecast to soon emerge off of Africa later this week.

"Steering winds favor a more northwest track with this second system and potential impacts to land will likely be reduced, should it develop this weekend into next week," Duffey said.

During El Nino, the number of named tropical systems in the Atlantic basin tends to be lower than average.

AccuWeather is forecasting eight tropical storms, four hurricanes and one major hurricane for the 2015 season with two to three landfalls in the United States. Ana and Bill made landfall in the U.S. during May and June respectively.