Scattered Code Yellow (Moderate) PM2.5 was observed today across the United States. The highest levels, Code Orange (Unhealthy for Sensitive Groups) levels were observed in the Southeast, across eastern Tennessee and wester South Carolina (top left). Continuing with the trend in posts, the HMS analysis team indicated several fires in the United States today, mainly concentrated in the Southeast, Southern Plains and Pacific Northwest states (top right). Copious amounts of fires were observed across the Yucatan Peninsula, and a huge swath of smoke associated with this activity is currently situated over the Gulf of Mexico. Today's aerosol optical depth (AOD) imagery from the MODIS overpass onboard the Terra satellite, detected the smoke, indicated elevated AOD throughout the Gulf as well as NRL's NAAPS aerosol model (bottom).