In aviation weather terminology, what does "VA" represent?

In aviation weather terminology, "VA" stands for Volcanic Ash. This term is critical because volcanic ash can pose significant hazards to aircraft. When a volcano erupts, it can release ash into the atmosphere, which can be ingested by engines, leading to a loss of power or even engine failure. The presence of volcanic ash can also reduce visibility and cause damage to other aircraft systems.

Understanding the implications of volcanic ash is crucial for dispatchers and pilots as it requires specific operational procedures to mitigate the associated risks. This includes avoiding ash clouds and monitoring ash advisories issued by meteorological agencies. The other options—Visually Alarming, Variable Airflow, and Volatile Atmosphere—do not correspond to any standard aviation weather terminology and therefore do not convey the specific risks and considerations associated with volcanic ash events.