Today's EPA Airnow animation shows PM2.5 Moderate (Code Yellow) AQI levels in the Pacific Northwest, and the Great Lakes States. Code Orange (Unhealthy for Sensitive Groups) PM2.5 concentrations were reported late in the day in Utah (top right image, courtesy of airnowtech.org) and Southern Indiana. The good air quality in the Mid-Atlantic, Ohio River Valley and Northeastern US was due to the strong winds and precipitation associated with a winter storm over this region. The National Weather Service reported there is significant threat of coastal erosion and flooding from Delaware to Massachusetts, until Friday.
NOAA Hazard Mapping and Smoke Product reports the presence of light smoke and aerosols over western and central Gulf of Mexico, extending possibly as far as Florida. AOD associated with this light smoke is visible in today's MODIS Terra retrieval. This region is consolidated along the frontal boundary that is dropping south, as shown in the NOAA Hydrometeorological Prediction Center image (below left image).