What is the precipitation code for hail larger than 1/4 inch?

The precipitation code for hail larger than 1/4 inch is represented by the code GR. This designation is specifically used in aviation weather reporting to indicate the occurrence of hail that exceeds this size threshold. Hail can significantly impact aircraft operations, both during flight and on the ground, thus understanding and recognizing this particular code is vital for pilots and meteorologists alike.

Other codes in the context aren't applicable to hail of this size. For example, PL stands for sleet, which is a different type of frozen precipitation. GS denotes small hail or ice pellets, suitable for smaller sizes, but not for those larger than 1/4 inch. Lastly, SH indicates rain showers that do not specifically refer to hail at all. Thus, understanding the specific meanings of these codes helps in correctly interpreting weather phenomena relevant to aviation.