By the time this magazine hits your mailbox, winter will be full-on in most parts of North America. Even if you spend most or all of your time in a warmer climate, your weather will change, with cooler temperatures, more wind and the occasional low-lying clouds, with rain. In other parts of North America, youll likely experience the full range of winters offerings sooner or later this season. Good luck. Of course, winters colder temperatures and denser air mean enhanced aircraft performance, at least when compared to summers typical heat and humidity. But the season brings its own set of aircraft performance challenges, especially when it comes to precipitation. This time of year, moisture from the sky can come in many different forms, not all of it liquid. And an airplane doesnt have to be airborne to be affected; merely parking one outside in winter precipitation can have a major impact on flight operations.