Ash concentration CSV files
Modelled volcanic ash concentration forecasts are available below. Volcanic ash forecasts are only available from London VAAC for volcanoes erupting within the London VAAC area.
The CSV files below supplement the London Volcanic Ash Advisory Graphics (VAG) and Advisories (VAA). They are to be used with caution.
The 200 microgram contour represents the outer edge of the low concentration zone and will approximate to that used in the VAG and VAA, however due to the automated nature of production the data within the CSV file and the VAA / VAG will not be identical.
In accordance with the definitions in the ICAO EUR/NAT Volcanic Ash contingency Plan (ICAO EUR Doc 19 and NAT Doc 06 Part II, December 2010 edition), the following additional contours are provided:
The 2000 microgram contour represents the upper bound of the 'low' concentration.
The 4000 microgram contour represents the lower bound of 'high' concentration.
Operators should refer to national NATAMs for official guidance on any restrictions/actions regarding flight in affected airspace, and the official boundaries applicable to such restrictions/actions.
Airlines operating in UK airspace should review the document "Guidance regarding flight operations in the vicinity of volcanic ash" which can be found on the CAA website.