NOAA's National Air Quality Forecast Guidance Capability: Reaching 50 States

For the last few years, the NWS, in conjunction with the EPA, has produced forecast guidance for surface ozone concentrations and smoke throughout the lower 48 states (CONUS). In addition to this guidance, the NWS is testing experimental versions of the Smoke Forecast Tool over Alaska (AK), with plans to implement it operationally by Fall 2009, and is beginning testing over Hawaii (HI) as well. Ozone predictions for AK and HI are in development; experimental testing is planned to begin in 2010.

NOAA's hour-by-hour forecast guidance, at 12km grid resolution, out to 48 hours, shows when and where predicted values of ozone and smoke are expected to reach harmful levels, in cities, suburbs and rural areas alike. Ozone forecasts are produced with a linked numerical predictions system: North American Mesoscale (NAM) weather predictions drive the Community Multiscale Air Quality (CMAQ) model developed by NOAA researchers for the US EPA. EPA provides the information on pollutant emissions and monitoring data on ground-level ozone and fine particles used for verification and evaluation of developmental products.

The Smoke Forecast Tool integrates NOAA/National Environmental Satellite, Data, and Information Service's satellite information on the location of wildfires with NWS weather inputs from NAM and smoke dispersion simulations from NOAA's Office of Oceanic and Atmospheric Research HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, to produce a 48-hour prediction of smoke transport and concentration, updated daily. The model also incorporates U.S. Forest Service estimates for wildfire smoke emissions based on vegetation cover.

As part of efforts to build a capability for quantitative particulate matter (PM) prediction, NWS is testing dust predictions based on HYSPLIT coupled with dust source potential of Ginoux et al. (2009). Dust and smoke predictions provide intermittent contributions to PM, which are verified with satellite observations of source-specific contributions to aerosols in the atmospheric column. Developmental testing of predicted aerosols based on EPA pollution inventories, in an expanded CMAQ version is ongoing.

Recent performance and verification of these forecast guidance products will be summarized. The guidance products are being evaluated and tested with a focus group of the state and local air quality forecasters, who provide next-day alerts of impending poor air quality for about 300 communities across the US. NWS field forecasters at the WFOs and NCEP are encouraged to share their weather expertise and coordinate with their corresponding state and local air quality forecasters. Since the initial operational implementation of NWS's air quality forecaster guidance in 2004, NWS forecasters have been increasing their outreach to state/local air quality forecasters along with the geographical coverage of the guidance.

This guidance is available on the web at http://www.weather.gov/aq/. Expanded coverage with experimental ozone predictions, from coast to coast, is available on http://www.weather.gov/aq-expr. Detailed information on our Air Quality Forecasts is available at http://www.weather.gov/ost/air_quality/.