Hurricane Donna - Meteorological History

Meteorological History

The precursor to this storm was a well-organized tropical disturbance which moved off the shore of Africa on August 28 and August 29. The crash of an airliner at Dakar on August 29 was attributed to this disturbance. Before reaching the Cape Verde Islands, the system was well enough organized to be considered a tropical depression on August 29. By August 30, the system became Tropical Storm Donna. Moving westward, intensification continued, bringing the cyclone to hurricane strength on September 1. For nine days, September 2 to 11, Donna consistently had maximum sustained winds of at least 115 mph (185 km/h) as it moved west-northwest, briefly achieving Category 5 strength. Donna passed through the northeasternmost Leeward Islands, subsequently missing Puerto Rico by 70 mi (110 km) to the north. The hurricane then skirted the Cuba on September 9 before heading for the Florida Keys.

The storm made its first Florida landfall in the community of Marathon, centered on Key Vaca in the middle Florida Keys. At the time, Donna was a Category 4 hurricane with estimated maximum sustained winds of 140 mph (230 km/h) and gusts of up to 180 mph (290 km/h), with a minimum central pressure of 930 mbar (27.46 inHg). The storm crossed into the Gulf of Mexico and its course shifted northward. Donna paralleled the southwest coast of Florida until it made a second Florida landfall between Naples and Fort Myers, again as a Category 4 hurricane. After crossing the Florida peninsula, it continued north and moved back out into the Atlantic Ocean near Daytona Beach. Donna made another landfall at Topsail Beach, North Carolina as a Category 2 hurricane. The storm continued up the Eastern Seaboard, and remained off the Mid-Atlantic Coast. Donna made a final landfall across eastern Long Island as strong Category 1, with winds near 95 mph (153 km/h).

Donna, unlike Hurricane Charley which followed a similar track in 2004, was a slow-moving storm. Donna dumped 10 in (250 mm) to 12 in (300 mm) of rain in the southern half of Florida, along with about seven inches in the northern half. The three weeks prior to Donna's landfall produced a 6 in (150 mm) to 7 in (180 mm) surplus in rain before the hurricane hit, exacerbating the problem. From the time it became a tropical depression to when it dissipated after becoming an extratropical storm, Donna roamed the Atlantic from August 29 to September 14, a total of 17 days.