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The Northwest Air Quality Forecast is an interactive viewer for AIRPACT-6, a numerical air quality forecasting system for the Pacific Northwest. Every day, the system runs the CMAQ chemical-transport model on a 4 km grid covering Washington, Oregon, Idaho, and neighboring areas, and produces a 72-hour forecast of surface fine-particle (PM2.5) and ozone concentrations. This site turns each morning's run into the animated map, time-series popups, and verification statistics you see here.
Hourly PM2.5 (µg/m³) and hourly ozone (ppb) are modeled surface concentrations, one map per forecast hour. Daily products follow the regulatory definitions: PM2.5 as the 24-hour mean and ozone as the MDA8 (the day's maximum 8-hour running mean). Overall daily AQI is the worse of the two, using U.S. EPA Air Quality Index breakpoints. AQI is computed in your browser from the concentrations, so coloring stays exact.
Monitor dots, observed curves in popups, and all performance statistics use real-time and recent observations from the U.S. EPA/partner AirNow network. Smoke plumes are the analyst-drawn NOAA Hazard Mapping System analysis (GOES satellite imagery, updated through the day). Fires appear as two layers, both served by NASA FIRMS: red-orange flames are 375 m VIIRS hotspots from the past 24 hours (S-NPP, NOAA-20, NOAA-21; shown within about a minute of overpass), and yellow "burning now" flames are detections from the geostationary GOES-West satellite's ABI Fire Detection and Characterization product — coarser (~2 km) but refreshed every few minutes. Two optional satellite imagery layers are served through NASA GIBS/Worldview: daily VIIRS true-color imagery (one image per day, from the early-afternoon overpass) and sub-daily GOES-West GeoColor imagery (true color by day, infrared at night, every 10 minutes; GeoColor is produced by CIRA/NOAA). Observations are labeled as such throughout the site — they are measurements, not forecast.
We verify it in the open. Every night the previous day's AirNow observations are paired with the archived forecasts that covered that day, and the model performance page reports bias, RMSE, correlation, and ozone-exceedance skill by site, region, and forecast lead time. Clicking any monitor on the map shows that site's recent skill.
Honest caveats: a 4 km model cannot resolve neighborhood-scale variations; wildfire smoke is the hardest case, since forecast skill depends on the fire-emission estimates fed into the model (improving these is active work); and terrain effects like valley inversions challenge any regional model. Use the verification numbers, not our enthusiasm, to judge trustworthiness.
AIRPACT-6 is developed by the Air Quality Research Lab at Washington State University. The operational AIRPACT-6 CMAQ pipeline is run by graduate student Priom Zarrah, with pipeline development support from graduate student Jahidul Islam. The visualization pipeline, this site, and the verification system are built and maintained by Prof. Jun Meng. The visualization layer was developed in collaboration with Claude (Anthropic).
This work is made possible by financial support from the NW-AIRQUEST consortium. AIRPACT has been developed over many years by the Laboratory for Atmospheric Research at Washington State University.
Northwest Air Quality Forecast (AIRPACT-6 visualization), Washington State University, https://nw-air-forecast.pages.dev/ (accessed YYYY-MM-DD).
Found a bug, want a feature, or have a question? Open an issue on GitHub. The visualization pipeline is open source at github.com/Jun-Meng/airpact6_InteractiveViewer.
This is a research forecast provided as-is, without warranty. For official air quality alerts and health guidance, consult your state or local air agency and AirNow.gov.