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HYSPLIT Volcanic Ash Model

See also the enhanced capability to calculate concentrations. Concentrations are calculated based on the given amount of ash in the eruption column. Users have options for describing both model inputs and outputs. If you find problems, please let us know by posting to the HYSPLIT Forum at


When a volcano has erupted, see the Volcanic Ash Advisories issued by Volcanic Ash Advisory Centers and the official volcanic ash forecasts (SIGMETS). In the U.S. VAAC areas of responsibility, priority should always be given to the HYSPLIT model volcanic ash cloud guidance charts for current or hypothetical eruptions.

Note that timely delivery of data and products from this server through the Internet is not guaranteed (see the disclaimer). This server is not operational and is not maintained 24 hours a day, 7 days a week. Do not rely on obtaining volcanic ash HYSPLIT products from this web site.

Publications using HYSPLIT results, maps or other READY products provided by NOAA ARL are requested to include an acknowledgement of, and citation to, the NOAA Air Resources Laboratory. Appropriate versions of the following are recommended:


Stein, A.F., Draxler, R.R, Rolph, G.D., Stunder, B.J.B., Cohen, M.D., and Ngan, F., (2015). NOAA's HYSPLIT atmospheric transport and dispersion modeling system, Bull. Amer. Meteor. Soc., 96, 2059-2077,

Rolph, G., Stein, A., and Stunder, B., (2017). Real-time Environmental Applications and Display sYstem: READY. Environmental Modelling & Software, 95, 210-228, (


The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website ( used in this publication.

Redistribution Permission

Permission to publish or redistribute HYSPLIT model results using forecast meteorological data from NOAA ARL can be obtained by providing relevant information (reason, to whom, from whom) via email to For further information, see the HYSPLIT Use Agreement.

Modified: November 21, 2022
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