The poor air quality continues in Utah with Unhealthy for Sensitive Groups readings today in Ogden and Logan. Levels were moderate in Salt Lake City and Provo. This story is not likely to end until spring when the ground thaws and higher boundary layer heights start again. In California, moderate air quality again is found in the lower San Joaquin Valley. In both of these locations, the combination of low boundary layer heights, stagnant air and wood burning are all combining to making air quality degraded.
Update: Feb 17, 2013 19:00 EST
Not much has changed today. Again the only two stations in the country that have reached the Unhealthy for Sensitive Groups range (orange) are in Utah. Today it is Brigham City and Ogden. The MODIS image left shows little evidence of such pollution. In fact, the reading for Logan Utah comes late in the day. Earlier Logan hit 80 µg m-3. That would put Logan into the code Red and perhaps into code Purple.