Moderate concentrations of Ozone were reported by AirNow in the central states and Mid-Atlantic region mainly during the afternoon (top left). Some stations reached unhealthy levels for sensitive groups in Missouri and Nebraska. On the other hand, PM2.5 levels were from moderate to unhealthy in Northern California and Idaho where several fires have been taking place. According to the fires, moderate to dense smoke plumes continue to be produced from the fires in the west (top right). A number of large wildfires scattered across the region from northern California to southwestern Montana and northwestern Wyoming were producing massive quantities of moderately dense to very thick smoke. The thickest smoke was located over northern California, central Idaho, western and southern Montana, and northern Wyoming. Additional moderately dense to thick smoke also spread farther to Central Canada. Modis true color image shows the thick smoke from the fires in California and Idaho (middle left).
High AOD values were detected also in the Rocky Mountains as well as in the Pacific Northwest. In addition to the event in the west, a very large area of thin to moderately dense smoke, also primarily from the large wildfires in the Western US, was visible moving to the east and southeast across south central to southeastern Canada, and much of the Central US extending eastward to at least as far as the Appalachians as seen in the top left image.
Particularly, lidar observations at the City College of New York, Hampton University and UMBC, institutions associated to NOAA-CREST detected different layers of smoke especially one between 5-6km originated in the Pacific Northwest fires (bottom). Overnight measurements are taking place to see the evolution of this aerosol and to examine if the plume enters and mixes into the planetary boundary layer (PBL).