National Air Quality Forecast System (AQFS) (O3) Graphic Forecast Displays Product Description Document (PDD) 6/1/04

Part I - Mission Connection

a.       Description of Product - The National Weather Service's National Air Quality Forecast System (AQFS) Ozone (O3) Graphic Forecast displays ( ) are web-based presentations of gridded forecast guidance originating from the Environmental Modeling Center (EMC) of the National Environmental Prediction (NCEP).The ozone data is displayed for a domain covering the northeast US for 1-hour and 8-hour averages. Additional information on the AQFS is available at:

The O3 grib files are produced from Eta-12 CMAQ (Community Multiscale Air Quality) modeling system that is run twice daily from the 0600 and 1200 UTC cycles and posted as graphic images to NCEP and EPA web sites per interagency agreement .  Forecast time projections will extend out to a minimum of 30 hours (0600 run) to a maximum of 48 hours (1200 run). Initially the domain will cover the northeast US for just O3. Additional coverage and pollutants will be added in future years.

b. Purpose AQFS has been developed in support of a Congressional mandate to implement an operational air quality forecast system to benefit public health. DOC/NOAA and EPA formed a partnership to transfer scientific advances in air quality monitoring and forecasting into NCEP's world class modeling realm. AQFS guidance will be used by state and local agency forecasters, as well as the media and private sector meteorologists as input to their AQ forecasts providing higher resolution and greater coverage (12 km general coverage) than the approximately 300 specific locations nationwide . The general public health will benefit from improved forecasts and mitigation of harmful impacts.. Expanded coverage and additional forecast pollutants such as particulate matter will be produced as the science and NOAA capabilities permit and in accordance with growing user needs.

c. Intended Audience - The NWS graphical AQ guidance products are intended for use by state and local agency forecasters, as well as the media and private sector meteorologists. The general public who may be adversely impacted by pollutants will also have access to the data via graphical output on multi-agency web sites.

d. Presentation Method - The data are presented as web-based graphic images. The AQFS provides ground level ozone (O3) for a domain covering the northeast US. In the future, the domain will expand to cover the entire US.

e. Feedback Mechanism - We are always seeking to improve our products based on user feedback. Please submit your comments by completing our brief experimental product survey. Comments may also be submitted by clicking on the Survey/Comments links on the experimental product web pages. Comments are being accepted. For general questions regarding the National Air Quality Forecast System, please email:


Part II - Technical Description

a.       Format & Science Basis - The AQFS is described at:

b.   Product Availability - The AQFS O3 graphics are produced twice daily based on the 0600 and 1200 Coordinated Universal Time (UTC). model cycles and are available at 0900 and 1330 EDT, respectively. Use the following URL to access real-time O3 graphics:

c.   Other Details A future AQ directive will be developed.