U.S. Air Quality

Weekend Edition: Large wildfires and unhealthy ozone conditions continue; despite passing of widespread severe wind event

Multiple massive wildfires across the west continue as the densest pockets of smoke extend across northern/central Utah and western Wyoming and Colorado. The HMS analysis team reports the very dense smoke is beginning to merge with other areas of moderately and light remnant smoke which has been affecting air quality for those living from the Plain states through the eastern seaboard. On Friday, PM2.5 AQI levels remained in the Moderate range for most, however greater levels of Unhealthy for Sensitive Groups (USG) were observed closer to the active fires in Utah. Ozone was a problem at the end of the week, as USG conditions were experienced within many Northeast, Mid-Atlatnic, Great Lakes, Southeast, MS Valley, and Plain states. Pockets of Unhealthy and Very Unhealthy were also reached in some of those locations (bottom left, courtesy AIRNow). The blazing temperatures experienced throughout this area Friday afternoon was partially to blame for the formation of the harmful ozone levels and also helped instigate significant atmosphere instability, thus dangerous weather. The Storm Predication Center's preliminary storm report indicates over 1,000 high wind events from Friday's severe weather (bottom,right). In terms of air quality, the sweeping of the powerful system helped usher in a new air mass and ozone conditions improved slightly on Saturday (middle left, courtesy AIRNow). Saturday's MODIS snapshot aboard the Terra satellite revealed elevated AOD throughout the aforementioned areas affected by smoke, as well as a large swath of raised AOD just offshore the east coast (middle, right). However, today, Sunday, the HMS smoke analysis and FIRMS active fire data suggests the large area of smoke covering the eastern half of the United States persists (bottom, left). Today's MODIS "True Color" image from the Terra satellite superimposed with AIRNow's AQI demonstrates the affects of poor air quality in the Mid-Atlantic with what appears to be widespread haze (bottom, right). Before noon today, the CAMNET haze camera shows hazy conditions along downtown Baltimore's skyline (last, left) and according to AIRNow's AQI Forecast (last, right) poor air quality is on the horizon again.