Sept. 1 (Bloomberg) -- Tropical Storm Felix formed near the Caribbean island of Grenada, becoming the sixth named storm of the 2007 Atlantic Hurricane season.

The system's maximum sustained winds strengthened to almost 40 miles (64 kilometers) per hour from 35 mph, the U.S. National Hurricane Center said in an advisory on its Web site at 5 a.m. Miami time today. The threshold for a tropical storm is 39 mph.

Felix was about 30 miles northwest of Grenada and was moving west at 18 mph at 5 a.m., the hurricane center said. Felix over the next five days may strengthen into a hurricane, with winds of at least 74 mph, as it tracks across the Caribbean, brushing Honduras before making landfall in Belize on Sep. 5, according to the center's five-day forecast.

As Felix formed in the Caribbean, over the Pacific, Tropical Storm Henriette plowed a course parallel to the Mexican coast, the hurricane center said. Henriette, which formed yesterday south of Acapulco, had winds of near 50 mph and was about 220 miles west of the Mexican resort at 4 a.m. local time today, and moving west-northwest at 12 mph, the center said.

Parts of the Mexican coast from Acapulco to Manzanillo were under tropical storm warning, and rainfall of up to 10 inches (25 centimeters) could provoke ``life-threatening flash floods and mudslides,'' the center said.

In the Caribbean, tropical storm warnings were issued for the Dutch islands of Aruba, Bonaire and Curacao, adding to existing warnings in place in Grenada and St. Vincent and the Grenadines, the hurricane center said. In Venezuela, a portion of coast from Cumana to Pedernales, including the holiday island of Margarita, was under tropical storm watch.

``Felix will move away from the southern Windward Islands later this morning and will be passing near the islands of Aruba Bonaire and Curacao late tonight or early Sunday morning,'' the hurricane center said.

To contact the reporter on this story: Alex Morales in London at amorales2@bloomberg.net.

Last Updated: September 1, 2007 06:08 EDT