Overview
VONA, or Volcano Observatory Notice to Aviation, are standardised messages issued by volcano observatories to provide VAAC (Volcanic Ash Advisory Centre), pilots, air traffic controllers, and dispatchers with crucial, real-time information about volcanic unrest or eruptions that could produce hazardous ash clouds, using plain language and a defined colour-coded system (Green, Yellow, Orange, Red) for immediate hazard assessment. These alerts are vital for ensuring aviation safety by warning of ash plumes, which can damage aircraft engines and systems.
Current VONA template (2025)
2025-2026 developments
In 2025, ICAO updated its requirements for State Volcano Observatories (SVOs) messaging to the aviation industry, and VONA format. WOVO’s VAAH programme ran a survey with SVOs to understand the state of play between volcano observatories and ICAO regulation, followed by a meeting late 2025 to present the results of the survey, present and discussthe updated ICAO requirements.
On 3 December 2025, WOVO hosted meetings attended by a total of 90 people (scheduled both in the morning and afternoon to accommodate different time zones). The attendance showed how much the topic is of relevance and how much SVOs people are committed to improving and working together on the tasks we are assigned by ICAO.
About 46 people attended the first meeting and 44 the second, from almost all countries where a State Volcano Observatory exists.
The recordings of the meetings are available on the YouTube WOVO channel (https://www.youtube.com/@WOVO-volcano). The presentation given by Dr. Paula Acethorp and Dr. Dave Schneider
More resources
The two latest State Letters (2025), with contents of relevance for SVOs, which have been sent this year to our governments (possibly to the Transport Ministry, or the Aviation Authority)
Summary of the 2025 survey of volcano observatories about their use of VONA