A mysterious blob has been showing up on Doppler radar this afternoon and evening near Van Wert, Ohio.
Rain has been moving in, but this blob is not actually precipitation falling from the sky.
So what is it?
Turns out this is the Blue Creek Wind Farm – owned by Avangrid Renewables – that straddles Van Wert and Paulding counties in northwest Ohio.
So why is this showing up on radar?
Large groups of power-generating windmills can have some influence on the weather pattern around them. They create turbulence in the lowest level of the atmosphere.
All large-wind turbines disrupt natural airflow to extract energy from wind. During the day, the effects from the disturbed airflow are negligible because natural turbulence mixes the lower layers of the atmosphere. However, in the evenings or at night this turbulence can easily be detected by Doppler radar when there is an atmospheric temperature inversion – a condition in which the temperature of the atmosphere increases with altitude in contrast to the normal decrease with altitude. When temperature inversion occurs, cold air underlies warmer air at higher altitudes.