Example Volcano Observatory Notice for Aviation (VONA) in the 2026 ICAO‑aligned format.

Released in March 2026, the updated Volcano Observatory Notice for Aviation (VONA) format uses standardized aviation terminology to describe volcanic activity and potential ash hazards for pilots and aviation authorities. The updated VONA follows recommended practices from the International Civil Aviation Organization. The USGS and its five volcano observatories will issue VONAs as needed in response to changes in volcanic activity across the United States.