Fires in northern California and Idaho are to blame for the widespread swath of remnant smoke stretching from the northern Pacific to Atlantic coastline (top left, courtesy HMS). Broad atmospheric ridging over the northern United States, with embedded mid-level westerlies, has aligned well over the past few days permitting transport of the smoke in the low to middle atmosphere ( ~ 5.5km )(top right, courtesy SPC). Today's lidar image from UMBC suggests several layers (likely smoke) over Baltimore, Maryland between 3-12km (bottom right). In terms of air quality, Code Yellow (Moderate) and Code Orange (Unhealthy for Sensitive Groups) AQI were reported over regions near smoke, such as the Pacific Northwest, Rocky Mountain, Plain, Great Lakes and Mid-Atlantic states (bottom right, courtesy AIRNow). Scattered Code Red (Unhealthy) AQI were also measured along the Idaho/Montana border, Colorado, and Oregon, and northern California.