MEXICO CITY – Hurricane Sandra, the strongest storm on record this late in the Pacific hurricane season, decreased from Category 4 to 3 on Thursday and was expected to weaken further before hitting Mexico at the weekend, forecasters said. At 0001 GMT, the hurricane was 235 kilometers (150 miles) south of Socorro Island, off Mexico’s west coast, according to Mexico’s national weather service, SMN. It was “gradually weakening and continues moving northward,” SMN said, with sustained winds of 195 kilometers per hour. Sandra reached Category 4 earlier on Thursday, the second-highest grade on the Saffir-Simpson scale. It was expected to carry on losing strength before making landfall as a tropical storm on late Friday or early Saturday. However, authorities warned Sandra could still generate heavy rain and waves of 2-2.5 meters (up to eight feet) in Baja California Sur state. The Pacific hurricane season, which runs from May to the end of November, has produced 18 named storms.