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corner effect An enhancement of wind speed near a low flat point of land or corner of an island due to the convergence of wind off the land with that over the water. This is a frictional effect of land on the wind. The wind on the land is backed (coming more from the left) relative to wind on the water, so when this wind emerges from a left-hand shore (looking windward) the wind off the land converges with the near shore winds to increase its speed relative to that farther offshore. See G448 for an illustration of the effect. In contrast, wind off a right-hand corner bends away from the main flow of air as it crosses the land and this divergence causes the wind to slacken somewhat in the region. Our new favorite way to predict where this effect will occur In the Northern Hemisphere is: with your back to the wind, expect enhanced winds off large low corners on your right hand side. Start with the Buys-Ballot law for finding direction to lowest pressure, which puts the wind on your back and your arms outstretched. Low pressure is on your left (Northern Hemisphere), and corner effect probability is at points on your right. So the Buys Ballot law gives you two things: direction to low pressure on your left, and potential corner effect winds on your right. This is reversed in the SH. When doing this test sailing up wind, you have to then turn around to see here you are going and remember which way your right hand was pointed when you had your back to the wind! Corner effect is a special case of an edge effect. See edge effects on wind.

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