MIAMI (AP) -- Tropical Storm Bud is still swirling well off the Mexican coast but is not strengthening.

The U.S. National Hurricane Center in Miami said Tuesday evening that Bud was centered about 440 miles (705 kilometers) southwest of Zihuatanejo, Mexico, and was moving toward the northwest near 14 mph (22 kph). It had maximum sustained winds of 40 mph (65 kph).

It was expected to turn northwest and slow down later Tuesday and turn north by Thursday morning. No coastal warnings or watches have been issued. Projections show it could be downgraded to a tropical depression by Sunday afternoon.

Meanwhile, Alberto offshore along the Atlantic has been downgraded to a post-tropical cyclone. Forecasters say it could fizzle out Thursday.