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HYSPLIT Automated Dispersion Model Simulations

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Overview

HYSPLIT has been configured to automatically produce atmospheric dispersion forecasts for several locations. These locations may change based on the needs of NOAA and its partners. Dispersion forecasts are produced either four times a day for some locations, or hourly for others. In both cases, the model assumes a unit of mass emission and uses two concentration grids: a fine grid (~1 km horizontal resolution) and a coarse grid (~10 km horizontal resolution).

For the four-times-a-day forecasts (60-hour emission), fine grid output is hourly from hour 1 to 12, and coarse grid output is every 2 hours from hour 2 to 60.

For the hourly updated forecasts (24-hour emission by default), fine grid output is hourly from hour 1 to 12, and coarse grid output is every 2 hours from hour 2 to 24. Upon request, the unit emission duration may be extended to a maximum of 72 hours.

Current Products


Modified: December 10, 2025
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