Tropical Depression 4 formed in the far eastern Atlantic Ocean and another depression could form in the Gulf of Mexico over the next day or so, the U.S. National Hurricane Center said on Monday.

In an advisory issued at 5 p.m. EDT (2100 GMT), the NHC said the center of Tropical Depression 4 was located about 620 miles west-southwest of the southernmost Cape Verde Islands and about 1,900 miles east of the Lesser Antilles.

Tropical Depression 4 is moving toward the west near 20 miles per hour with maximum sustained winds near 35 mph.

The NHC said Tropical Depression 4 could strengthen into a tropical storm (winds of 39-73 mph) tonight or on Tuesday. The NHC will name the next tropical storm Dean.

In about four days, the NHC said Tropical Depression 4 could strengthen into a Category 1 hurricane with winds of 74-95 mph and a Category 2 hurricane with winds of 96-110 mph in about five days.

The NHC expects to issue another advisory at 11 p.m.

Most of the weather models show Tropical Depression 4 crossing the Leeward Islands later this week and moving into the eastern Caribbean Sea. The Leeward Islands include the U.S. Virgin Islands, the British Virgin Islands, Saint Martin, Saba, Saint Kitts, Nevis, Barbuda, Antigua, Montserrat, Guadeloupe and Dominica.

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 LOW-PRESSURE

In the south-central Gulf of Mexico, the NHC noted that a broad low-pressure area was centered just north of the northeastern tip of the Yucatan Peninsula in Mexico.

The NHC said upper-level winds are gradually becoming more favorable for development of this system and a tropical depression could form later Monday or Tuesday as the low-pressure area moves to the west-northwest at 10 to 15 mph.

The NHC said an Air Force reconnaissance plane is scheduled to investigate the system on Tuesday if necessary.

The weather models showed the low-pressure system, located in the south-central Gulf of Mexico, headed towards the coast between Texas and Mexico over the next few days.