Air Quality: Fire Weather

Investigating conditions that lead to wildfires, smoke, air quality impacts and their aftermath.

flames and black smoke are in the foreground, with a window in the middle of the image, between the flames and the smoke where you can see the LA skyline in the background and some trees closer to and in the flames. The sky is a bright orange.

2025 wildfire threatening homes and wildlife in Los Angeles. Credit: Strikernia via stock.adobe.com

Wildfires are not only dangerous, but also increasing in severity and prevalence, particularly in the western states and into the midwest. NOAA has a number of research activities underway to better predict, respond to and recover from the increasing threat of wildfires.

As the nation’s leading weather and climate science agency, NOAA provides critical outlooks, forecasts and early warning products, monitoring temperature, precipitation and soil moisture across the nation. ARL is partnered with a number of laboratories across NOAA for wildfire projects.

The specific atmospheric conditions that create a high risk of wildfire, such as low humidity, strong winds, and dry vegetation are referred to as fire weather. A critical part of fire weather research and prediction is understanding the continuous exchanges of energy and matter between the land and the boundary layer, known as land-atmosphere interactions. These processes feed into regional weather patterns and impact conditions conducive to the start and spread of wildfires. Land-atmosphere interactions are much more difficult to model and forecast in mountainous regions with complex terrain and more research in these areas is critical to NOAA’s work in this area. ARL is a critical collaborator for NOAA’s fire weather observatories work researching this specific area.

ARL is building two mobile observing towers, part of the Collaborative Lower Atmospheric Mobile Profiling Systems (CLAMPS), and a fixed site at our Idaho Falls location as part of this research. One mobile system is currently deployed at NOAA’s Marshall Test Bed and the other will be built and deployed in early 2026.

Short-Term Fire Weather. ARL, in partnership with NOAA’s Global Systems Lab (GSL) and Environmental Modeling Center (EMC), will improve the delivery of real-time fire weather, smoke and air quality modeling and aerosol data assimilation through the development of NOAA’s next generation numerical weather prediction (NWP) model, the Rapid-Refresh Forecasting System (RRFS). RRFS will replace the current HRRR-Smoke system in the near future. Key benefits include improved accuracy for weather and visibility, smoke and dust transport, air quality, and fire weather forecasts.

Black and white outline of the U.S. with a swirl of colors swooping from Washington State diagonally across the country through the southeastern border of Texas before swooping back up across the west side of the southern east coast states moving towards the coastline all the way up to the northernmost states and beyond. A large part of the country is covered in the lightest two or three shades of blue, with the main diagonal area from the west through Texas incorporating purples, reds, oranges, yellows, greens and darker blues. The East coast swoop is mostly dark blues before the same purple, red, orange, yellow and green can be seen at the top right of the map over the border in Canada.

NOAA HRRR-Smoke model showing vertically integrated smoke. Generated August 24, 2025. Credit: NOAA

Real-time fire weather, smoke modeling and aerosol data assimilation products under development will use the RRFS-Smoke tool. The RRFS-smoke tool will transition from research to operations with new algorithms and tools that forecast emissions and smoke for the new RRFS North American domain at 3 km resolution. The ARL-developed evaluation and analysis system MELODIES-MONET will be assessed for possible use in the wildfire testbed.

Additionally, ARL develops the Air Quality Model (AQM) which provides a more comprehensive air quality description and can also predict smoke and fire. The unique approach of the current AQM version is that it incorporates data from multiple satellite sources to reduce uncertainty. Constant observations focused on specific areas of the Earth allow hourly updates on wildfire emissions, based on heat signatures, rather than the once a day updates from previous satellites. These background concentrations of air quality give us the full effect of fire weather.

Brown/red, purple, orange and yellow colors swirl on a background of lesser concentrations designated by greens. The deeper warm colors look to originate around the center of Washington state and in Canada. As the video progresses, the concentrations of smoke swirl and change, moving eastward. — AQM is used in NOAA's Air Quality Viewer. The deeper colors indicate higher concentrations in this forecast of column-integrated smoke in the Pacific Northwest taken on September 22, 2025. Credit: NOAA (Click to view animation)

Long-Term Fire Weather. ARL also developed NOAA’s Global Ensemble Forecast System Aerosol Model (GEFS-Aerosols), which is a component of the National Weather Service Unified Forecast System (UFS). UFS was a collaboration with three other OAR labs and the Environmental Modeling Center. This allows five day forecasts and full descriptions of fires globally. ARL is also involved in developing the next generation of this project, the UFS Research to Operations project.