A growing tropical depression raised the possibility of a storm watch for Mexico's gulf coast on Wednesday, while Tropical Storm Karen strengthened to near hurricane status in the open Atlantic.

The depression, the 13th of the Atlantic hurricane season, could strengthen into a named storm over the next day in the southwestern Gulf of Mexico, National Hurricane Center meteorologists said.

A tropical storm watch was likely for part of Mexico's gulf coast by late Wednesday, the center said.

At 11 a.m. EDT, the depression was centered about 205 miles east-southeast of Tampico, Mexico, and was drifting south at about 2 mph with top sustained wind near 35 mph. Minimum wind speed for a tropical storm is 39 mph.

It was expected to move slowly and erratically over the next 24 hours.

Karen was centered about 1,225 miles east of the Windward Islands, with top sustained wind near 70 mph, forecasters said. That was just 4 mph shy of the minimum for being upgraded to a hurricane, but it posed no immediate threat to land.

Karen was moving toward the west-northwest at about 13 mph. Tropical storm-force wind extended up to 85 miles outward from the center.