ARL News

National Volcanic Ash Operations Plan

August 30, 2007

The Office of the Federal Coordinator for Meteorological Services and Supporting Research (OFCM) will soon publish the “National Volcanic Ash Operations Plan for Aviation and Support of the International Civil Aviation Organization (ICAO) International Airways Volcano Watch”. ARL’s role, outlined in the plan, is to conduct research to improve volcanic ash dispersion forecast guidance and transfer updated capabilities to the NWS National Centers for Environmental Prediction (NCEP) for operational use. A description of the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) transport and dispersion model is included in the plan.


ARL volcanic ash involvement goes back to the 1980 Mt. St. Helens eruption when trajectory forecast products were issued. By the 1989-1990 Mt. Redoubt, Alaska, eruptions, ARL trajectories were sent to the NESDIS Satellite Analysis Branch, which issued products to the FAA and others. In 1997 ICAO designated a network of Volcanic Ash Advisory Centers (VAAC), two of which NOAA operates. The U.S. VAAC area of responsibility includes the U.S., most of the North Pacific, Central America, the Caribbean, and northern South America. The VAACs issue text and graphical advisories and HYSPLIT model output. In the last ICAO 18-month reporting period about 3500 advisories and 100 dispersion forecasts were issued by the U.S. VAAC.

The OFCM Plan “supports the observing, tracking, monitoring, forecasting and reporting of volcanic ash in the atmosphere as it affects the safety of flight operation in the U.S. … and U.S.[air-traffic-] controlled international/oceanic service.” NOAA signatory organizations to the plan are the NWS Office of Climate, Water, and Weather Services, the NESDIS Office of Satellite Data Processing and Distribution, and ARL. Other signatory agencies are the Federal Aviation Administration, U.S. Geological Survey, U.S. Air Force, NASA, and the Smithsonian Institution.


Volcanic ash can cause significant impacts to aircraft and aviation over a wide region. These impacts can include damage to aircraft and interruption of engine operation. The aviation community relies on NOAA’s volcanic ash warnings, satellite analyses, and forecasts for supporting safe operations.

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