What does "RA" signify in a METAR report?

In a METAR report, "RA" signifies "Rain." This is an essential designation used in aviation weather observations to indicate the presence of precipitation. The use of standardized abbreviations in METAR reports helps pilots, air traffic controllers, and meteorologists quickly interpret weather conditions, which is crucial for flight safety.

Understanding that "RA" directly relates to precipitation allows individuals in the field to assess weather impacts on flight operations, including visibility, runway conditions, and potential for low ceilings. This is particularly vital during takeoff and landing phases when weather can significantly affect aircraft performance and safety.

The other options do not align with established weather reporting conventions used in METAR formats and therefore do not accurately represent the conditions being reported.