What indicates volcanic ash on a METAR?

The indication of volcanic ash on a METAR report is represented by the abbreviation "VA." This code is utilized internationally in aviation meteorology to alert pilots and airlines about the presence of volcanic ash in the atmosphere, which is essential for safety. The presence of volcanic ash can significantly affect flight operations, leading to potential hazards such as engine damage and reduced visibility.

Understanding this representation is critical for flight dispatchers and pilots, as volcanic ash can have serious implications for flight safety and planning. By using "VA," METAR reports communicate this critical information succinctly and effectively, allowing the necessary precautions to be taken to ensure safe air travel.

The other codes, while they may represent other meteorological phenomena, do not indicate volcanic ash specifically. Thus, "VA" stands out as the correct notation for this particular hazard in aviation meteorology.