What does the code DRDU represent in weather observations?

The code DRDU is used in weather observations to indicate "low drifting dust." This phenomenon occurs when particles, specifically dust, are lifted from the ground and are blown about by the wind at lower altitudes. It signifies that the visibility may be reduced due to these airborne particles, which can have implications for flight safety and overall weather conditions.

Understanding the implications of each type of weather observation code is crucial for interpreting weather reports accurately. While options like blowing sand, blowing spray, and moderate ice pellet showers refer to different weather phenomena, only low drifting dust aligns with the code DRDU. Each of these conditions has its own codes and definitions in the METAR (Meteorological Aerodrome Report) system, which is used to provide up-to-date and standardized weather information in aviation.