In the icing group 641104, what does '4' signify?

In the icing group coded as 641104, the number '4' signifies the type of icing that is present in that particular layer of the atmosphere. The icing group uses a standardized coding system to communicate specific information about icing conditions, helping pilots and meteorologists assess the severity and nature of icing hazards.

In this context, different numerical values in the icing group correspond to various types of icing, such as rime, clear, or mixed icing. Understanding what the '4' represents allows for effective decision-making regarding flight operations in potentially hazardous conditions.

This coding system is crucial for pilots, as it informs them about the specific risks associated with different types of icing, enabling them to plan their flights accordingly and maintain safety.