Extreme events such as wind gusts, rapid wind direction changes, or passage of energetic atmospheric fronts impose critical loads on wind turbines. Lidar measurements, with high resolution in time and space, can provide detailed information on atmospheric events considered extreme or anomalous for the wind energy operations.

The paper discusses the results of lidar measurements of the mean wind and turbulence characteristics of the flow for several nights from the Lamar Low-Level Jet Program in southeastern Colorado in September 2003. During these nights, hub-high wind speeds were 15-25 m/s, much greater than nominal rated wind speeds(11-12 m/s) for modern multi-megawatt turbine operations according to IEC specifications.

During one of the study night, September 13, a cold front passed through the observational site, resulting in a rapid change of wind speed and direction (hub- height winds increase from 10 to 25 m/s and wind direction changed in 180 degree.)

Detailed analysis of turbulence statistics and wind shear across the rotor swept area, and comparison of these parameters for periods of strong and light winds will be given