MEXICO CITY — A strengthening Tropical Storm Nora was rolling Thursday toward a hurricane hit on Mexico’s Pacific Coast over the weekend and later on the Baja California Peninsula.

The U.S. National Hurricane Center said the storm could bring dangerous flash floods and mudslides through the weekend as it parallels the coast, likely grazing the point below the Puerto Vallarta region on Saturday and then possibly the Los Cabos resort region on Monday.

The storm was centered about 320 miles (515 kilometers) south of the port city of Lazaro Cardenas on Thursday afternoon and it was heading to the west-northwest at 9 mph (15 kph).

Nora had maximum sustained winds of 40 mph (65 kph), but it was expected to reach hurricane force on Saturday. It was a big system, with tropical storm-force winds extending as far as 205 miles (335 kilometers) from the center.

The hurricane center said the storm could dump 8-12 inches (20 to 30 centimeters) of rain over the central Mexican coast, with isolated maximums of up to 20 inches (50 centimeters.

It was also kicking up heavy surf.