Cuba is bracing for Hurricane Michelle, which is swirling in the western Caribbean with maximum winds of 215 kilometers an hour. The storm is expected to make landfall over the island's western region later Sunday.

Cuban officials say Michelle could prove to be the worst storm to strike the island in 50 years. A powerful, Category Four Hurricane on a one-to-five scale, Michelle is centered south of Cuba's western tip and moving on a north-northeasterly path.

Already, the hurricane's outer bands have lashed vast stretches of Cuba's western half. Authorities have evacuated 150,000 residents of the capital, Havana, where it is feared that punishing winds and torrential rains could cause buildings to collapse. The government has canceled all domestic and international flights until Monday.

Over the next 24-hours, weather forecasters expect Michelle will veer on a more easterly track, taking the storm along the Florida Straits once it passes over Cuba. It is not known whether the hurricane will strike Florida, but local officials are taking no chances. Saturday, tourists and non-residents were ordered out of the Florida Keys.

According to Miami-Dade County Mayor Alex Penelas, there is no cause for panic, but counsels south Floridians to remain alert and prepared. "You need to continue to monitor the system," he said. "You need to stay calm, to any extent possible. We are asking the people of south Florida to begin preparations. Prepare a family disaster plan - that is the first thing they should be doing. Identify where you would go if you were told to evacuate, especially if you are in one of our mandatory evacuation areas."

Michelle, the 13th named storm of the Atlantic Hurricane season, has more than doubled in strength since Thursday. It is blamed for massive flooding and at least a dozen deaths in Central America and Jamaica.