January 6, 2009
Haze and Fog in California; Small Fires in South Florida; Good Air Quality in the East
There were Code Orange (Unhealthy for Sensitive Groups) and Code Yellow (Moderate) PM2.5 conditions scattered across the West Coast today, as shown by the hourly loop of AQI values (below on left). Most of the rest of the country enjoyed Code Green (Good) air quality under the influence of a complicated weather system that is bringing icy and wintery conditions to the Northeast and severe weather and flash flooding to the Southeast. The widespread cloud shield over most of the Eastern U.S. associated with the weather-maker is evident in today’s MODIS Terra true color image in Google Earth (below on right).
 |  |
There was a fair amount of cloud cover over the Western U.S. today, too. Nevertheless, some haze and fog are discernable at the edges of the bright white clouds over central and northern California in today’s MODIS Terra true color image (below on left). According to NOAA’s Aviation Weather Center, several ASOS (automated surface observing system) sites in northern California and southern Oregon are reporting fog at this hour, and several sites in central California are reporting haze, with visibilities ranging from 1-6 miles. The haze and fog are likely responsible for today’s Code Orange and Yellow PM2.5 readings. These conditions are expected to continue tomorrow across the Central Valley; Wednesday’s air quality forecasts for the region in Google Earth (below on right) indicate that Code Orange conditions are predicted for Sacramento and Fresno, and Code Yellow for the rest of the area.
 |  |
NOAA’s Hazard Mapping System reports that were a few small fires burning in south Florida this morning. Smoke plumes from the fires are visible over Lake Okeechobee in today’s MODIS Terra true color image for south Florida overlaid with AQI values in Google Earth (below). Due to the small size and narrow extent of the smoke, it did not appear to impact air quality at the surface.
