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Old 29th June 2011, 06:45 AM   #4
Philip
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Join Date: Aug 2006
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Seems that you are seeing cellular bursts which come down rather than from across the landscape which as with gusty winds on a open ocean can be caused by a difference in speed or direction between high and low level wind movements. Also while all may appear to be calm on the water surface, refracted heat may cause a push back of thermal breeze activity and thus returning cellular bursts. These have different sailing angles as the WS sails through or around the edges or seeks a consistent path through these edge to edge. This is superimposed on the 'normal' wind generated as the differential between high and low pressure system gradients where the wind direction and velocity is vectored by the rotation of the globe and the friction of the larger scale surface media establishing the general wind direction and velocity. The direction of the gust lull sequences is subsequently magnified by the local landscape when flowing/ bending about nearby hills, forests or what ever obstacles. Anyway that is my rough interpretation not being a meteorologist by any means and much more accurate explanations are available from standard sailing text books in your local library probably.
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