Hurricane Dean was the fourth named storm and second hurricane of the 1989 Atlantic hurricane season. Dean formed east of the Lesser Antilles on the last day of July, and although it threatened the northern Leeward Islands for a time, it turned away without incident. However, it passed directly over Bermuda as a Category 2 hurricane. Dean was the first Atlantic tropical cyclone to bring hurricane conditions to the island since Hurricane Emily in 1987. Dean subsequently passed over southeastern Atlantic Canada as a rapidly accelerating tropical storm.
Dean caused $9,000,000 (1989 USD) in damage but did not kill anyone.
|Formation||July 31, 1989|
|Dissipation||August 8, 1989|
|Highest winds||105 mph|
|Lowest pressure||968 mbar|
|Damages||$9,000,000 (1989 USD)|
|Areas affected||Leeward Islands, Puerto Rico, Bermuda, Atlantic Canada|
|Part of the||1989 Atlantic hurricane season|
Dean developed from a tropical wave that moved off the coast of Africa on July 27. The wave moved westward across the tropical Atlantic and gradually organized, with the first Dvorak classifications beginning on July 31. At 0600 UTC that day, the wave had organized enough to be designated Tropical Depression Five while located midway between the Cape Verde Islands and the Lesser Antilles. The cyclone moved generally westward and became a tropical storm by 0600 UTC August 1. Dean then moved west-northwest while continuing to intensify, and by 1200 UTC August 2, Dean attained hurricane status. By August 3, Dean began decelerating and took a turn to the northwest to a weakening ridge to the north caused by an eastward moving mid-latitude trough along the East Coast of the United States. By August 4, Dean turned to the north as the aforementioned trough intensified. Near 1800 UTC August 6, Dean's eastern eyewall passed over the island of Bermuda, and became the first tropical cyclone to bring hurricane force sustained winds to the island since Hurricane Emily of 1987. Dean is estimated to have reached its peak intensity of 105 mph just after 0000 UTC August 7, by which time the hurricane was already past Bermuda. After passing Bermuda, Dean turned northeast and accelerated in response to an upper-level trough moving eastward across the northeastern United States. Dean passed over Sable Island, Nova Scotia as a tropical storm, and then subsequently began to lose tropical characteristics as it passed over southeastern Newfoundland. Dean became extratropical on August 9 over the northern Atlantic Ocean while accelerating rapidly northeastward at a forward speed of 50 mph.
Dean was a difficult storm to accurately forecast as it was approaching the eastern Caribbean. Even though most computer models indicated that Dean would skirt the Leeward Islands, the models were not consistent with this forecast. Consequently, watches and warnings were postponed for the Leeward Islands and Puerto Rico due to uncertainty in the future track of the tropical cyclone. One forecast in particular indicated that Dean could approach south Florida within 3 to 4 days.
The National Hurricane Center issued a Hurricane Warning for the island of Guadeloupe and the rest of the Leeward Islands extending all the way to the Virgin Islands. Residents throughout the Leeward Islands were ordered to evacuate, due to the uncertainty in Dean's future track. In the British Virgin Islands, 80 American and Canadian tourists evacuated to hotels. In Puerto Rico, residents were advised to secure and/or store loose objects, as well as stock up on emergency supplies. In the capital city of San Juan, a total of 1.1 million residents went to local supermarkets in order to buy emergency supplies due to the possible threat from Dean. In Humacao, the National Guard evacuated 1,966 residents who were living along a coastal highway. The islands of Martinique and Dominica were put under a Hurricane Watch by the NHC, due to the possible threat from Dean. When it was clear that Dean posed no significant threat to the island, the aforementioned Hurricane Warning was discontinued for Guadeloupe. In addition to this, all watches and warnings were discontinued for Martinique and Dominica, as well. As Dean moved westward, a Hurricane Watch was issued for the Turks and Caicos Islands. Shortly thereafter, the watch was canceled as Dean turned northward toward Bermuda.
On August 5, a Hurricane Watch was issued for the island of Bermuda as Dean approached. On August 6, the watch was upgraded to a warning as Dean drew closer. Dean caused the cancellation of numerous inbound and outbound flights from the island.
The NHC also posted a Hurricane Warning in Atlantic Canada, namely for Nova Scotia and Cape Sable, where Canadian forecasters also issued a high wind advisory.
Dean's outer rainbands produced heavy rains as well as wind gusts in excess of 75 mph on Antigua and Barbuda. There were no reports of damage or fatalities throughout the Leeward Islands.
Even though Dean's center remained well away from the United States coast, it produced storm tides up to 1.7 feet in North Carolina.
Dean caught a sailboat that was heading for Bermuda off guard. The sailboat had no radio equipment, and was spotted by a reconnaissance aircraft that was investigating the hurricane. The passengers aboard the aforementioned boat did not receive any injuries.
On the island itself, Dean produced sustained winds as high as 81 mph, with gusts as high as 113 mph. Dean's hurricane force winds caused considerable damage to power lines, which left around 65,000 residents on the island without electricity. In addition, the strong winds produced minor roof damage to some buildings on the island. At Hamilton Harbor, 20 pleasure boats were damaged or torn from their moorings due to rough seas caused by Dean's strong winds. The highest rainfall total reported on the island in association with Hurricane Dean was over 5 inches, and many locations on the island received anywhere from 2 to 5 inches of rain from the hurricane. Dean's heavy rainfall contributed to flooding, which caused damage to around 15 homes. In addition, Dean injured 16 people on the island, 5 of which were critically injured. Fortunately, there were no reported fatalities. Dean caused $9,000,000 (1989 USD) in damage on the island.
In Atlantic Canada, Dean produced hurricane force winds on Nova Scotia and Sable Island, while Newfoundland experienced tropical storm force winds from the hurricane. Offshore, waves in excess of 26 feet were reported, and Sable Island got 0.59 inches of rain from the hurricane. Dean caused no known damage throughout Atlantic Canada. Offshore, three sailors had to be rescued by the Canadian Coast Guard when their boat got dismasted during the storm.