The international aviation industry receives information on location and movement of clouds of volcanic ash from Volcanic Ash Advisory Centers (VAAC) around the world. The US VAACs in Anchorage, Alaska, and Washington, DC, work in concert with seven other VAACs: London, Montreal, Toulouse, Tokyo, Darwin, Wellington, and Buenos Aires. In addition to the NWS, the US VAACs are supported by NOAA/National Environmental Satellite, Data, and Information Service and by NOAA/Office of Oceanic and Atmospheric Research's Air Resources Laboratory and Earth System Research Laboratory.
Collaboration among VAACs has been problematic in the past, most notably during the 2010 eruption of Eyjafjallajökull in Iceland, which produced an estimated $2 billion impact internationally. The worldwide volcanic ash community responded by forming a highly productive working group led by the NWS, UKMET and the Meteorological Service of Canada (MSC). The outcome of this working group was instituting a collaborative analysis and forecast process among the NWS, UKMET, and MSC and an agreed-to list of priorities for improving the observations and models required to analyze and predict volcanic ash clouds. These efforts have resulted in better collaborative forecasts and related decision making as was apparent in the services provided during the 2011 Grimsvötn Volcano eruption. In the most recent endeavors, the world scientific and operational communities have collaborated on the following: improvements in observation and forecast capabilities for volcanic ash; closer coordination among VAACs, facilitated by creation of a set of best practices; and aggressive effort to develop international volcanic ash standards for aviation through the International Civil Aviation Organization in concert with the World Meteorological Organization.