mardi 6 octobre 2009

tempête tropicale GRACE / 6 oct 2006

Si tu ne vas pas a elle,..................... elle vient a toi !!

Surprise! A 70-mph tropical storm popped up seemingly out of nowhere early this morning, in a region of the Atlantic not ordinarily prone to tropical storm formation. Tropical Storm Grace formed at 41.2° north latitude, in a remote ocean area near the Azores Islands. This is the farthest northeast an Atlantic tropical storm has ever formed since satellite observations began in the 1960s. Since 1960, only one tropical storm has formed farther north--Tropical Storm Alberto of 1988, which formed at 41.5°N, off the coast of Cape Cod, Massachusetts. Satellite imagery revealed that Grace formed an eyewall and well-defined eye this morning, though the storm's tropical storm-force winds did not extend out very far from the center. Last night, the center of Grace passed about 20 miles west of Ponta Delgada in the eastern Azores, which recorded sustained winds of 31 mph, gusting to 44 mph. Grace formed over chilly waters of about 23°C, well below the usual threshold of 26°C required for tropical storm formation. Grace's formation was aided by some very cold temperatures in the upper atmosphere (-54°C at 200 mb), which made the atmosphere more unstable than usual. The storm won't be around much longer, as Grace is already over much colder waters of 21°C, and is headed towards even colder waters.

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Le grenier ou la cave