Icing » Icing Forecasting Icing Type

Empirical studies have shown the type of icing depends on the ambient temperature as well as the types of clouds (vertical motions) in the environment.
- Rime Icing occurs at temperatures colder than -15°C but can also occur at warmer temperatures in stratiform clouds.
- Clear Icing occurs at temperatures between 0 and -8°C, in cumulus clouds, and/or freezing precipitation.
- Mixed Icing (rime and clear) occurs in cumulus clouds at temperatures of -9 to -15°C.
Therefore, to evaluate the potential for icing from a skew-T plot, forecasters need to determine the thickness of the cloud/moist layer and the potential for supercooled conditions by examining the temperature, dewpoint depression, and lapse rate within the sounding.