1947 Florida–Georgia Hurricane

The 1947 Florida–Georgia hurricane (Air Weather Service designation: KingMultiple sources:
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) was a moderate hurricane that caused catastrophic flooding in South Florida and the Everglades in mid-October 1947. The ninth tropical storm and fourth hurricane of the 1947 Atlantic hurricane season, it first developed on October 9 in the southern Caribbean Sea and hence moved north by west until a few days later it struck western Cuba. The cyclone then turned sharply to the northeast, accelerated, and strengthened to a hurricane, within 30 hours crossing the southern Florida peninsula. Across South Florida, the storm produced widespread rainfall of up to and severe flooding, among the worst ever recorded in the area, that led to efforts by the United States Congress to improve drainage in the region.

Once over the Atlantic Ocean on October 13, the storm made history when it was the first to be targeted for modification by government and private agencies; dry ice was spread by airplanes throughout the storm in an unsuccessful effort to weaken the hurricane, though changes in the track were initially blamed upon the experiment. On the same day as that of the seeding, the cyclone slowed dramatically and turned westward, making landfall on the morning of October 15 south of Savannah, Georgia. Across the U.S. states of Georgia and South Carolina, the small hurricane produced tides up to and significant damage to 1,500 structures, but the death toll was limited to one person. The system dissipated the next day over Alabama, having caused $3.26 million in losses along its path.

Meteorological history

At 18:00 UTC on October 8, a tropical depression developed in the Intertropical Convergence Zone about 65 miles (105 km) west-northwest of Isla de Providencia, Colombia, near .Multiple sources:
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Moving generally west of due north, the depression gradually strengthened, becoming a tropical storm a day later. At 15:30 UTC on October 10, the Hurricane Hunters—reconnaissance aircraft—first intercepted the storm, registering a pressure of , which suggested maximum sustained winds of 54 mph (87 km/h). Afterward, the storm began curving east of due north, while nearing the island of Cuba. At 07:00 UTC October 11, the deepening tropical cyclone made landfall near La Coloma, Pinar del Río Province, with winds of 65 mph (100 km/h). After crossing the western portion of the island, the cyclone underwent robust intensification over the southeastern Gulf of Mexico, with most of its strengthening occurring in under four hours. At 17:16 UTC aircraft entered the eye of the storm and measured a pressure of , which corresponded to winds of 85 mph (140 km/h), making the storm equivalent to a Category 1 hurricane on the present-day Saffir–Simpson scale. The cyclone then angled sharply northeastward, passing near the Dry Tortugas en route to peninsular Florida. At 02:00 UTC on October 12, the hurricane impacted Southwest Florida north of Cape Sable with a slightly stronger intensity of , along with winds of 90 mph (150 km/h); the estimated pressure was based on a barometric measurement of taken at 07:00 UTC in Fort Lauderdale, on the edge of the eye, that was "'still falling'" at the time. Then a smaller-than-average storm, it crossed the mostly uninhabited Everglades and passed over the Miami metropolitan area between Fort Lauderdale and Pompano Beach.

Shortly before 08:00 UTC it entered the Atlantic Ocean near Hillsboro Inlet Light, which experienced the center of a hurricane for the second time in a month, with winds of 80 mph (130 km/h). After leaving South Florida, the hurricane passed north of the Bahamas while gradually weakening. By 00:00 UTC on October 13, the cyclone degenerated into a strong tropical storm, but regained hurricane status 12 hours later. Over the next day, the storm slowed substantially and began veering landward, executing a semicircular turn northward and westward, a trajectory that threatened the Southeastern United States. During the night of October 13–14 a dearth of in-situ observations prevented forecasters from appraising its exact location and movement.Multiple sources:
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At this time reconnaissance aircraft penetrating the storm reported winds of up to , and data from the aircraft suggested the ill-defined center "split in two".Multiple sources:
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The secondary center meandered westward and became dominant on October 14, while slowly consolidating and intensifying. Late that day aircraft reported peak winds of in the storm. At 00:00 UTC on October 15, the cyclone intensified into the equivalent of a low-end Category 2 hurricane, and began accelerating westward toward Georgia. Six hours later it attained its peak of 105 mph (165 km/h), which it maintained until landfall around 11:00 UTC near Ossabaw Island, approximately south of Savannah. The lowest pressure in the eye at landfall was estimated to have been near , based in part on a report from a ship just offshore more than eight hours earlier. At the time, the coverage of hurricane-force winds was small, extending about in all directions from the eye. The storm weakened rapidly as it crossed inland over Georgia, and by 00:00 UTC on October 16 it weakened to a tropical storm, dissipating 18 hours later over Alabama.

Preparations

On October 10, watercraft in the Straits of Florida, the northwestern Caribbean, and the Yucatán Channel were advised to proceed cautiously. The steamship ''Florida'', bound for Havana