Tropical Storm Dean formed in the open Atlantic on Tuesday, but remained far from land, forecasters said.

At 11 a.m. EDT, the storm was centered about 1,490 miles east of the Lesser Antilles in the Caribbean, about halfway across the ocean from Africa, according to the National Hurricane Center. It had top sustained winds of 40 mph, just above the threshold to be a named storm.

Dean was moving over increasingly warmer waters, where atmospheric conditions could create a favorable environment for intensification into a hurricane by Friday, forecasters said. It was cruising west at about 23 mph. Forecasters said it is too early to tell where Dean will go.

Hurricanes sustain winds of at least 74 mph.

Hurricane forecasters expect this year's Atlantic hurricane season to be busier than average. Last week, they said up to 16 tropical storms are likely to form, with nine strengthening into hurricanes.

The season runs from June 1 to Nov. 30, but August typically marks the start of the most active period. Ten tropical storms developed in the Atlantic last year, but only two made landfall in the United States.