NOAA-EPA’s New National Air Quality Forecast Capability: Transitioning Research to Operations

In partnership with the US EPA, NOAA has deployed the initial stage of a national air quality forecast capability into the National Weather Service (NWS) operational suite as of September, 2004. This new capability, an end-to-end forecast guidance system, provides twice daily predictions of hour-by-hour ground-level ozone concentrations on a 12km grid, disseminated over operational NWS and EPA dataservers. Forecast guidance products are hosted on operational dataservers: fully backed up, with archiving and near-real-time verification in place to monitor forecast accuracy. Required accuracy of 90% and reliability of 95% on-time delivery were demonstrated in the pre-deployment testing period during Summer, 2004, and are being maintained as the initial forecast domain (Northeastern US) expands Nationwide. Testing of expanded capabilities is underway: experimental forecast guidance will be produced during summer, 2005 over the entire Eastern half of the contiguous US. Following developmental testing and evaluation in 2004 over Eastern US, system upgrades to improve guidance accuracy, focusing on improved model linkage, updated emissions information, improved treatments of solar radiation for photolysis rate estimation, and improved treatments of vertical mixing and transport within clouds, are being incorporated for experimental pre-deployment testing, to begin June 2005. Targeted deployment of nationwide ozone forecasts within 5 years will be followed by the addition of particulate matter forecasts and an extended forecast period- out to day 2 and beyond.

The fast-track development, testing and implementation of the initial operational capability result from close cooperation among NOAA, EPA, and a focus group of state and local air quality forecasters. NOAA/EPA researchers and NWS developers adapted and integrated CMAQ , a comprehensive atmospheric chemistry and transport model, for NWS' operational environment and adapted NWS' operational mesoscale weather forecast models (Eta-12, transitioning to WRF), to provide meteorological parameters needed to drive the air quality emissions preprocessing and reactive transport codes. EPA develops, maintains and updates emissions inventory information, provides current monitoring data for verification, and provides forecast guidance in terms of their health-based air quality index. State and local air quality forecasters are working with the NOAA/EPA in developmental testing of the forecast guidance to examine local area performance and utility. Collaborations with the Canadian air quality forecast community are also benefiting development areas, including longer-range objectives in particulate matter forecasting. The capability also benefits from the efforts of the broader research communities of NOAA and all sectors involved in improving understanding of pollutant emission, transformation, transportation and deposition in the lowest levels of the atmosphere.