Tropical storm Raymond was churning along 180 miles south-southwest of Acapulco, Mexico, early Sunday, U.S. forecasters said. Raymond was expected to become a hurricane during the next two days. The storm was headed northwest at 7 mph, and packed sustained winds of 40 mph, the National Hurricane Center in Miami said. A tropical storm warning was in effect for Acapulco to Lazaro Cardenas, Mexico, on the Pacific coast. The hurricane center said people on the south-central coast of Mexico should monitor the storm, as a hurricane watch may be needed later if the storm gets stronger. Forecasters said the storm is expected to turn northward with a gradual decrease in its forward speed. Raymond is expected to slowly approach the Mexican coast late Monday, \"then begin to meander,\" the hurricane center said.