Thursday, August 16, 2012

Hurricane Gordon (2012)

Storm Active: August 15-20

A strong tropical wave and associated low pressure system emerged off of Africa on August 9 a produced an organized area of showers and thunderstorms. However, it tracked west-northwest, and took a path slightly north of the Cape Verde Islands. Soon after, unfavorable conditions caused convection associated with the system to diminish.

However, the low continued to move across the open Atlantic, and emerged into a area of lower wind shear on August 14. Later that day, significant shower activity developed, and the circulation became better organized. On August 15, the satellite presentation was sufficiently impressive to merit the classification of the system as Tropical Depression Eight, despite surface pressures remaining somewhat high in the area.

The cyclone was at that time well east of Bermuda, and it moved north as it exploited a weakness in the Bermuda high ridge. By early on August 16, convection had markedly increased, and the system was upgraded to Tropical Storm Gordon. Deep convection continued to concentrate about the center during that day, and Gordon strengthened as it curved to the east under the influence of a subtropical ridge.

By late that night, Gordon had reached an intensity of 70 mph winds and a pressure of 995 mb. However, under the influence of moderate shear, it weakened slightly that night.

Gordon reasserted itself early on August 18, and a prominent eye feature appeared, resulting in the upgrade of Gordon to a hurricane. The cyclone continued to strengthen throughout the day as it moved west, becoming a Category 2 hurricane that evening as it approached the Azores, and reaching its peak intensity of 110 mph winds and a pressure of 965 mb late that night.

By the morning of August 19, Gordon began to interact with a trough to its northwest, and took a turn to the north, adopting a east-northeast motion. In addition, an increase in shear and a decrease in sea surface temperatures caused Gordon to steadily weaken that day. Conditions in the Azores began to deteriorate during the evening.

Early on August 20, Gordon made landfall in Santa Maria Island of the Azores as a minimal hurricane, where winds gusts in excess of 80 mph were recorded. The convection in the southern portion of the system had degraded significantly by this time, and the cyclone was in the midst of extratropical transition. By later in the morning, Gordon had weakened to a tropical storm and lifted out of the Azores. The system was declared extratropical that afternoon, and dissipated a few days later. Minor damage and no injuries were reported in the Azores.

Gordon at peak intensity moving rapidly east over the central north Atlantic.

Track of Gordon.

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