When can low level vertical windshear typically be expected?

Low-level vertical windshear often occurs in association with radiation inversions. This phenomenon typically happens at night when the earth's surface cools rapidly, resulting in the formation of an inversion layer. During this time, warmer air traps cooler air near the ground, leading to stable conditions that can cause a significant difference in wind speed and direction at different altitudes.

This type of windshear is particularly critical for aviation since it can be encountered during takeoff and landing phases, where vertical fluctuations can lead to sudden changes in aircraft performance and control. In contrast, unstable atmospheres or certain times of the year do not consistently produce the same kind of windshear effects, making the association with radiation inversions a key factor for pilots to be aware of for safety in flight operations.