“I caught a reference to wind shear in the destination airport’s TAF. Ought I to call off the flight?”
The pilot posing the question was seasoned enough to map out a trip meticulously but was still in the process of learning with each fresh encounter. As he was unsure about the significance of “WS020/32020KT” in the Terminal Aerodrome Forecast, he desired me to offer him a definite verdict on whether to proceed.
Normally, I refrain from playing the role of a dispatcher when I haven’t been well-informed about the weather situation. However, I did know that a front was advancing, and the time of day was conducive to temperature inversion. Those two elements logically increased the probability of low-level wind shear, so I expressed my thoughts on his trip to that effect. Out of an abundance of caution, he chose not to go.
For light aircraft, a wind shear note in a TAF is not inevitably a perilous warning, but rather a flag indicating that something is out there, demanding that we be prepared to handle it. It shouldn’t be conflated with wind shear alerts produced by LLWAS systems at major airports, which signify serious, real-time threats. Airliners have exhausted their spare performance capacity during takeoff and landing, so a loss of airspeed due to a wind shear encounter can be life-threatening.
