NASSAU, Bahamas (AP) - Hurricane Floyd strengthened to a very dangerous storm Monday with 155 mph wind, surprising forecasters and charging toward the Bahamas on a path that also threatened the Florida coast. Heavy rain started falling in parts of the Bahamas Monday as residents scrambled for emergency supplies, shelters opened, schools closed and shop owners boarded up windows. Bahamas officials ordered a mandatory evacuation of coastal areas exposed to potential flooding. If Floyd stayed on its current path, it would pass Monday night or early Tuesday 120 miles east of Nassau, the Bahamian capital.