The weather systems that produce steady rain to the west tend break up by the time they reach the midwest due to the influence of the Great Lakes and other systems from the Gulf (south) and Canada (north), and then rebuild again to the east of the Great Lakes. Most of our rain is the result of daily warming and humidity, and tends not to develop until later in the day. In the event of rain, we spend that time looking in more detail at the lessons, airplane operations, and answering questions. When the rain ends, we return to the flying field and resume training. Double sessions are used to get in flying time if rain is forecasted, or to make up for rain delays.