The 1956 Atlantic hurricane season featured a decent number of tropical cyclones, although most tropical storms and hurricanes affected land. There were twelve tropical storms, a third of which became hurricanes. One of the hurricanes strengthened to the equivalent of a major hurricane, which is a Category 3 or greater on the Saffir–Simpson scale. The strongest hurricane of the season was Betsy, which was also the most damaging storm of the season: it destroyed 15,000 houses and left $40 million in damage in Puerto Rico. Betsy was also the deadliest of the season, having killed 18 people in the French West Indies, two from a shipwreck in the Caribbean Sea, and 16 in Puerto Rico. Tropical Storm Dora struck Mexico in September and killed 27 people. The season officially started on June 15, although an unnamed storm developed about a week prior over the western North Atlantic Ocean. A later storm that formed over the Gulf of Mexico on June 12 alleviated drought conditions in the south-central United States. Hurricane Anna developed in late July and hit Mexico. Tropical storms Carla and Ethel both formed near the Bahamas and moved northeastward until dissipating. The only hurricane that hit the contiguous United States was Hurricane Flossy. One of the final storms of the year, Greta, was an unusually large hurricane that produced high waves from Florida to the Lesser Antilles. It developed in the western Caribbean and moved across much of the southeastern United States, causing $24.8 million in damage and 15 deaths. There were also several tropical depressions, as well as one subtropical cyclone, in the season. Season summary The season officially began on June 15, the date that the Weather Bureau office in Miami, Florida, under the direction of Gordon Dunn, began daily monitoring of all tropical disturbances and cyclones across the northern Atlantic Ocean. The agency had access to the hurricane hunters, a fleet of aircraft that obtain data by flying into storms. The Weather Bureau, in collaboration with other agencies, began a five–year project in 1956 to obtain and analyze data on the structure of hurricanes. The season officially ended on November 15. There were a total of twelve tropical storms during the season, five of which were unnamed. Of all the storms, four were hurricanes. Compared to the average activity from the previous two decades, the season's activity was below normal despite average sea surface temperatures