Tropical Storm Andres strengthened off the southwestern coast of Mexico on Monday, prompting emergency preparations for a storm that forecasters said could become a hurricane in coming days. It was too soon to know whether Andres' center would hit land, but forecasters said tropical storm-force winds were likely to hit the coast within a day somewhere along the western coast from Lazar Cardenas to Manzanillo. The city government of Acapulco prepared 120 shelters and warned residents to stay indoors, especially some 15,000 people in 20 zones most at risk of flooding. The National Weather Service (NWS) in Miami, Florida said that Andres was about 195 kilometers southwest of Zihuatanejo at 1500 GMT. The storm was moving slowly toward the west-northwest near 7 kilometers per hour (kph). Maximum sustained winds were near 85 kph with higher gusts. The forecast track showed the storm as moving along the central Mexican coast on Tuesday before bending toward the west before reaching the Los Cabos resorts at the southern tip of the Baja California Peninsula Thursday night or Friday. Forecasters said Andres could become a hurricane with sustained winds of at least 119 kph by Tuesday night. Late Sunday, Andres became the first named storm of the Eastern Pacific hurricane season, which started May 15 and ends November 30 and is usually busiest between July and September. But Andres is a late arrival. It has been 40 years since it took so long for a named storm to develop in the Eastern pacific season. U.S. government forecasters have predicted a near-normal or below-normal Pacific season, with the possibility of 13 to 18 named storms, including six to 10 hurricanes.