Volcanic Ash Advisory

A Volcanic Ash Advisory is an official meteorological product issued by Volcanic Ash Advisory Centres (VAACs) warning aviation of the presence, movement, and forecast trajectory of volcanic ash clouds.

• Nine VAACs worldwide provide coverage for all volcanic regions
• Issued as both text advisories (VAA) and graphical products (VAG)
• Include current and forecast ash cloud position, altitude, and movement
• SIGMETs for volcanic ash are issued by the responsible meteorological watch office
• Volcanic ash can cause complete engine failure by melting and resolidifying on turbine components
• The 2010 Eyjafjallajökull eruption caused the largest aviation shutdown since WWII (over 100,000 flights cancelled)
• Airlines and pilots must avoid areas of known volcanic ash contamination