Tropical Storm Carlotta is nearing hurricane strength as it moves toward southern Mexico's Pacific coast.

The storm's maximum sustained winds early Friday are near 70 mph (110 kph). Additional strengthening forecast and the U.S. National Hurricane Center in Miami says Carlotta is expected to be a hurricane by Friday afternoon.

A hurricane warning is in effect for Mexico's coast from Salina Cruz to Punta Maldonado.

The tropical storm is centered about 190 miles (305 kilometers) south-southeast of Puerto Angel and 400 miles (645 kilometers) southeast of Acapulco.

Hurricane conditions are expected in the warning area by Friday night and a storm surge is expected to cause significant coastal flooding. The Mexican states of Guerrero, Oaxaca and Chiapas could see up to a foot of rain that could cause flash floods and mudslides.