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Graphical Ventilation Forecast

The Ventilation Index (also known as the Clearing Index) is defined as the Mixing Height (depth of the mixed layer in 100's of feet above ground level) multiplied by the Transport Wind (average wind in the mixed layer in knots) and is represented by the following equation VI= (Mix Hght/100) x Trans Wind. Values between 0 and 300 generally represent poor dispersion, 300 and 600 fair dispersion, and 600-1000 good dispersion. However, smoke management agencies are encouraged to develop criteria that are suitable and representative of dispersion conditions in their local area.

If you have any questions about this product please contact the National Weather Service Office in Pendleton, Oregon at 541-276-7832.
Sat, Mar 28, 2015 Sun, Mar 29, 2015 Mon, Mar 30, 2015

US Dept of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
Pendleton Weather Forecast Office
2001 NW 56th Drive
Pendleton, OR 97801

Tel: (541) 276-7832

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