Which contraction represents 'Clear' in weather observations?

The correct contraction for 'Clear' in weather observations is represented by CLR. This abbreviation is widely recognized and used in aviation weather reporting, making it clear and concise for air traffic control and pilots. The use of CLR helps streamline communication, especially in contexts where brevity is important, such as aviation, where weather conditions must be conveyed quickly and efficiently.

The other options do not accurately represent 'Clear' in this context. For example, CLE does not have an established meaning in weather observation, while CLD typically stands for 'Cloudy', which is fundamentally different from 'Clear'. CLRLY, although it intuitively might seem related, is not an official contraction in meteorological terms. Thus, CLR stands out as the definitive and accepted abbreviation for 'Clear'.