Icing occurs when water droplets in liquid state at temperatures below 0 °C (supercooled water) strike a surface and freeze instantly. It affects aircraft, power lines, wind turbines, and roads.
Types and aviation hazards
Clear ice (transparent, dense, hard to remove), rime ice (granular, lighter), and frost are distinguished. In aviation, icing on wings disrupts the aerodynamic profile, increases weight, and can cause loss of control. Areas of freezing rain and clouds containing supercooled water (especially cumulonimbus) are most dangerous.