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USGS provides volcanic ash cloud forecasts and ashfall information.

Volcanic ash is a far-reaching hazard that can affect structures, power generation and transmission, water districts, ground and air transportation, agriculture, and human health. The USGS Volcano Hazards Program offers several resources aimed at forecasting, remediating, and reporting volcanic ash.

There are specific actions to take during and after ashfall events.

The Volcanic Ash Working Group is a partnership between several international organizations, including the USGS, that offers practical information about and actions to take before, during, and after volcanic ash events.

Ash3D provides forecasts of ash clouds and ashfall.

The USGS provides forecasts of expected ash dispersion (ash clouds) and deposition (ash fall) from volcanic eruptions using a numerical atmospheric transport model called Ash3D that was developed by USGS scientists specifically to deal with volcanic plumes. The model can be run for actual or hypothetical eruptions, and can be accessed via the Ash3D web application.

USGS Volcano Observatories run Ash3D for any US volcano at elevated alert level (excepting effusive Hawaiian volcanoes) assuming a reasonable hypothetical eruption. Should an eruption occur, the responsible volcano observatory updates the forecast with actual observations (eruption start time and duration, plume height) as they become available. Model results are posted on Observatory websites, as well as provided to the National Weather Service for use in its public  Ashfall Advisories.

In Alaska? Experiencing Ash? Report it!

Is Ash Falling? is a simple four step input tool that anyone can use to report observations of ashfall in Alaska. Alaska Volcano Observatory scientists use the information, even reports of NO ashfall, to conduct research and help keep National Weather Service Ashfall Advisories current. The Is Ash Falling? tool also provides instructions on how to collect an ash sample to send back to AVO for analysis.