U.S. weather forecasters say Hurricane Dora has strengthened into a major hurricane off Mexico's Pacific coast.

The National Hurricane Center in Miami Wednesday classified Dora as a Category 4 storm on the 5-point Saffir-Simpson scale of hurricane intensity. Forecasters say Dora has winds of 215 kilometers per hour and is expected to move nearly parallel to the coast of southwestern Mexico over the next day or so. The latest report positioned the storm 530 kilometers south of Cabo Corrientes, Mexico, moving in a west-northwesterly direction.

Mexican authorities issued a tropical storm watch from Lazaro Cardenas to Cabo Corrientes.

Dora is the fourth named storm of this year's Pacific hurricane season. Forecasters say it could strengthen more before weakening on Friday.

Elsewhere, a new tropical storm, named Cindy, has formed in the open central Atlantic, but is expected to remain far from land. The storm was about 2,400 kilometers west of the Azores.

Forecasters also say Tropical Storm Bret has weakened slightly in the Atlantic as it moves northeast. At last report, the weather system was about 775 kilometers west of Bermuda.