Tropical Storm Dean forms in Atlantic: NHC

A tropical depression is seen forming over the central Atlantic in an NOAA satellite image taken August 14, 2007. Tropical Storm Dean formed in the Atlantic Ocean, midway between western Africa and the Caribbean Sea, the U.S. National Hurricane Center said Tuesday.

NEW YORK (Reuters) - Tropical Storm Dean formed in the Atlantic Ocean on Tuesday, midway between western Africa and the Caribbean Sea, the U.S. National Hurricane Center said.

Meanwhile, the energy market continued to watch the Gulf of Mexico, where a tropical depression that could threaten U.S. oil and natural gas facilities may form tonight or tomorrow.

The NHC said in an advisory issued shortly before 5 p.m. EDT that the center of Dean was located about 1,140 miles west of the southernmost Cape Verde Islands and about 1,390 miles east of the Lesser Antilles.

Dean was moving westward at about 21 miles per hour, with maximum sustained winds near 40 mph.

The NHC said Dean could strengthen into a Category 1 hurricane with winds of 74-95 mph in two to three days and a Category 2 (winds of 96-110 mph) or Category 3 (winds of 111-130 mph) storm in four or five days.

The NHC plans to issue another advisory on Dean at 11 p.m.

The latest computer weather models showed the storm reaching the Lesser Antilles during the next several days but had it heading further south than previously expected, moving into the Caribbean Sea well south of Puerto Rico.

The Lesser Antilles stretch from Trinidad in the south to the Virgin Islands in the north. The models showed the storm heading toward or slightly north of Barbados.

The energy market watches for tropical storms because they can disrupt U.S. oil and natural gas production and refining if they enter the Gulf of Mexico.

Commodities traders also track tropical storms because they can damage crops in Florida and along the Gulf Coast.

GULF OF MEXICO DEPRESSION POSSIBLE

The NHC said a tropical depression could be forming in the south central Gulf of Mexico.

In an outlook issued after 5 p.m. EDT, the NHC said the system was moving west-northwest or northwest at 10 to 15 mph.

An Air Force reconnaissance plane investigated the weather system and did not find the circulation that would indicate a tropical cyclone had formed.

But the hurricane center said upper-level winds were becoming more favorable for development and a depression could form Tuesday night or Wednesday.

The weather models showed the system would likely strike land near the Texas and Mexico border over the next few days.