MEXICO CITY—Tropical Storm Rick formed Friday off Mexico’s southern Pacific coast and is forecast to hit that coast at hurricane strength early next week. The U.S. National Hurricane Center said Rick was located about 305 miles (490 kilometers) south of the resort of Zihuatanejo, which is west of Acapaulco. The storm had winds of 45 mph (75 kph), but is expected to strengthen to as much as 90 mph (145 kph) in the coming days. It was moving west-northwest at 7 miles per hour (11 kph). The center warned Rick could produce flash flooding and mudslides. It was expected to hit along a stretch of coast west of Zihuatanejo that holds no resorts but does include the seaport of Lazaro Cardenas.