MIAMI - Forecasters say Tropical Storm Cristina has formed off the southwestern coast of Mexico and is expected to blow into a hurricane later in the week.

The National Hurricane Center in Miami, Florida, says the storm late Monday was about 155 miles (255 kilometers) south-southwest of Zihuatanejo, Mexico.

Maximum sustained winds are about 40 mph (65 kph). It is moving west at about 2 mph (4 kph) and is expected to keep moving in that direction out to sea.

There are no coastal watches or warnings in effect.