HAVANA—Tropical Storm Elsa swept along Cuba’s southern coast early Monday, and forecasters said it could make landfall on the island’s central shore by midafternoon. By Sunday, Cuban officials had evacuated 180,000 people as a precaution against the possibility of heavy flooding from a storm that already battered several Caribbean islands, killing at least three people. Most of those evacuated stayed at relatives’ homes, others went to government shelters, and hundreds living in mountainous areas took refuge in caves prepared for emergencies. Elsa was forecast to cross over Cuba by Monday night and then head for Florida, where Gov. Ron DeSantis declared a state of emergency in 15 counties, including in Miami-Dade County, where a high-rise condominium building collapsed on June 24. Late Sunday, Elsa’s center was about 270 miles (440 kilometers) southeast of Havana and moving northwest at 15 mph (24 kph). Its maximum sustained winds had strengthened a bit …