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Alberto was a long-lived Cape Verde hurricane that remained at sea through its lifetime. It is the longest-lived Atlantic tropical cyclone to form in August, and the third-longest-lived of record in the Atlantic. Alberto's track included intensifying into a hurricane three times, a large anticyclonic loop that took five days, and extratropical transition near 53°N. a. Synoptic HistoryA well-developed tropical wave was observed in satellite imagery over central Africa on 30 July. This system progressed steadily westward and moved off the coast on 3 August. Development occurred quickly upon reaching the Atlantic, and the wave became Tropical Depression Three at 1800 UTC that day. The cyclone moved west-northwestward at 17-23 mph and became Tropical Storm Alberto early the next day. Alberto continued to strengthen and reached hurricane status early on the 6th. This was coincident with a brief westward turn. The hurricane resumed a west-northwestward motion later that day, which continued as Alberto reached a first peak in intensity of 92 mph on the 7th. A strong upper-level low developed west and southwest of Alberto on 7-8 August. This caused an increase in vertical shear, a northwestward turn on the 8th, and weakening to a tropical storm on the 9th. Alberto continued quickly northwestward on the 10th while it regained hurricane strength. A gradual curve northward and north-northeastward through a break in the subtropical ridge occurred on 11-12 August. Alberto passed about 300 nautical miles east of Bermuda on the 11th. The hurricane reached its second and greatest peak intensity of 127 mph on the 12th, when a 50 nautical mile wide eye was present. Increasing upper level westerlies caused weakening on the 13th and 14th as Alberto moved east-northeastward, with the cyclone losing most of its convection as it became a tropical storm on the 14th. A westerly trough that had been guiding Alberto outran the storm, and strong ridging developed to the north and west. This caused Alberto to turn southward on 15 August, southwestward on 16 August, and westward on 17 August. The storm started to re-intensify on the 17th, and it regained hurricane status for the third time the next day. A third peak intensity of 104 mph, along with a 60 nautical mile wide eye, occurred on the 20th. The hurricane completed its loop during this period, turning northwestward on the 18th, northward on the 19th, and north-northeastward on the 20th and 21st. Weakening and acceleration occurred on 22 August, and Alberto again weakened to a tropical storm before becoming extratropical the next day. Extratropical Alberto continued north-northeastward, passing near Iceland on the 24th. Winds dropped below gale force as the increasingly poorly-defined center turned east-northeastward on the 25th, and Alberto finally dissipated about 75 nautical miles east of Jan Mayen Island later that day.
b. Meteorological StatisticsOther data were scarce. Alberto was far from land, and no reconnaissance flights were made. Only a few ships encountered the storm. A ship with the call sign MZYF3 (name unknown) reported 51 mph winds and a 1007.8 mb pressure at 0600 UTC 4 August; this was the basis for upgrading the cyclone to a tropical storm. A drifting buoy near the center reported 90 mph at 0900 UTC 8 August, while another drifting buoy reported 93 kt at 0900 UTC 10 August; however, the reliability of these measurements is suspect. Yet another drifting buoy just south of the center reported a 991.8 mb pressure near1800 UTC 11 August. There is one notable ship report. The Conti Sydney (call sign DEHU) reported 39 mph at 0600 UTC 3 August as the pre-Alberto disturbance was moving off the African coast. This suggests Alberto may have become a tropical storm earlier than indicated in the best track. This observation is not supported by satellite intensity estimates.
c. Casualty and Damage StatisticsThe National Hurricane Center has received no reports of damage or casualties.
Maximum Intensity For Hurricane Alberto
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