Tropical storm Erika continued to strengthen as it reached the Eastern Caribbean and appeared to be headed for the U.S. East Coast early next week, the U.S. National Hurricane Center said on Thursday. Erika could reach hurricane status near Florida’s east coast by Monday morning, the Miami-based government forecaster said. The last hurricane to hit Florida was Wilma in October 2005. While the forecasters can be reasonably certain of Erika’s path using computer models, give or take a couple of hundred miles, its intensity is harder to predict and it could fall apart as it passes over land and battles hostile winds.