The Virginia Department of Environmental Quality's Office of Air Quality Assessments (OAQA) performs local-scale dispersion modeling and regional-scale photochemical modeling.  The OAQA also issues daily air quality forecasts for localities in Virginia.

This site contains the following sections:

Dispersion Modeling - generally associated with the construction permit application process and is used to predict the air quality impact of new or modified emission sources.  Other uses of dispersion modeling include: analysis of monitored violations of the National Ambient Air Quality Standards (NAAQS), assistance in planning, and the development of rules.   

Photochemical Modeling - utilizes computer models to characterize the impact of emissions originating in other states on Virginia's air quality as well as characterizing the impact of emissions originating in Virginia on other state’s air quality.  This type of modeling is conducted in house and through coordination with regional planning organizations.

Air Quality Forecasting - The air quality forecast is the most visible element of the program and is seen by a large segment of the public on local TV news weather segments.  Expected ozone and fine particulate matter (PM2.5) levels, in terms of color code and Air Quality Index (AQI), are forecasted by Virginia DEQ meteorologists.  These forecasts are distributed to local media (television, radio, and newspaper) and to area businesses and individuals.  The forecast and current conditions are displayed on the Virginia DEQ air quality page. Separate forecasts are issued for the Northern Virginia, Richmond, Hampton Roads, Roanoke, and Winchester areas.