WINDSHEAR LAYER

Luis San Martin

Not all fronts have associated wind shear. In fact, shear is normally a problem only in those fronts with steep wind gradients. As with so many things associated with weather, there is no absolute rule, but a couple of clues tell you that wind shear may occur:

• The temperature difference across the front at the surface is 10 oF (5 oC) or more.

• The front is moving at a speed of at least 30 knots.

You can get clues about the presence of wind shear during the weather briefing by checking these two factors. Ask the briefer and, if these factors are present, be prepared for the possibility of shear on approach.