How would heavy freezing drizzle be encoded for transmission in an observation?

Heavy freezing drizzle is identified in aviation weather reports by specific encoding conventions. The correct encoding, which is +FZDZ, signifies that the weather phenomenon is not only freezing drizzle (FZDZ) but is also occurring at a heavy intensity, denoted by the ‘+’ symbol. This allows meteorologists and pilots to quickly understand the severity of the icing conditions they might encounter.

The encoding system is vital for ensuring that weather conditions are communicated efficiently and accurately to support aviation safety. When a report includes heavy freezing drizzle, it directly impacts decision-making related to flight safety, de-icing procedures, and route planning.

In contrast, the other encodings do not accurately represent heavy freezing drizzle. For example, -FZDZ would indicate light freezing drizzle, which does not convey the severity of the conditions. HZ refers to haze and does not pertain to freezing conditions. Finally, FZDZ alone lacks the intensity designation that is crucial for understanding the potential hazards associated with heavy icing.