The poor air quality episodes continue to be concentrated in the Western portion of the US (top, left - AIRNow), Unhealthy levels of PM2.5 for sensitive groups (code orange) was observed in Central California, with associated elevated AOD as can be seen in GASP animation (top, right) and MODIS Aqua retrievals (bottom, left). Code orange was also observed in Northern Utah, as well as in Southeast Oregon where code red was also observed for a few hours in the early morning until late afternoon and then again later at night. Moderate levels on the other hand, was observed throughout the Pacific Northwest region as well as in Montana and Idaho. Some isolated regions in the South, Midwest and Mid Atlantic also experienced brief peaks of moderate levels.
As I am blogging in retrospect, the last image is this morning's (01/19) webcam shot from the Utah State University in which you get a view of Cache Valley from the Old Main Hill. Very hazy, low visibility conditions as of 9am MST. Air Quality Action Day has been issued to a number of cities in Utah today (Saturday).