Moderate PM2.5 AQIs plague the West Coast as well as much of the Eastern US, seemingly parallel to the coast line (EPA AirNow, top left). USG conditions appear around 4PM EDT in Washington State. The plentiful wildfires producing thick plumes of smoke over Washington, Northern California, and British Columbia are mixing with the smoke from the still burning wildfires in the NW Territories--the main cause of air pollution in the region (NOAA HMS Google Earth, top right). The NAAPS Aerosol Model (bottom left) predicts the smoke surface concentration over the wildfire sites to exceed 128 ug/m^3. The combined mass of the thickest smoke is seen making its way Northeasterly into Idaho and Montana, which explains high AOD levels seen over the Pacific Northwest, Northern Rocky Mountain States and British Columbia (MODIS Terra, bottom right).
MODIS Terra also reveals elevated AOD levels over the Great Lakes Region, presumably attributed to the remnant smoke from Canadian wildfires, reaching a surface concentration of 16 ug/m^3. Sulfates are also predicted to affect the Eastern US, reaching 8 ug/m^3 over the Mississippi Valley and Great Lakes Region into most of Pennsylvania and Western New York, presumably the cause of Moderate AQIs in the area. Over the next couple of days, smoke over the East Coast is expected to dissipate, leaving only the heavy smoke over the wildfires in both Northern California and Washington State. Lidar observations in Baltimore show the first signs of smoke making in it to the east coast. The smoke is above the boundary layer, not impacting the local air quality. The diurnal evolution of the planetary boundary layer is captured in the lidar timeseries. It rose from below 500m at 12:20 UTC (8:20 local time) to max heights of 1.3 km. Around 23:00 UTC (7:00 pm) the PBL starts to drop to heights around 800m.