29. A pilot can expect a wind-shear zone in a temperature inversion whenever the windspeed at 2,000 to 4,000 feet above the surface is at least

An increase in temperature with altitude is defined as a temperature inversion. A pilot can be relatively certain of a shear zone in the inversion if the pilot knows the wind at 2,000 to 4,000 feet is 25 knots or more.