June 23, 2009
Smoke Keeps PM2.5 in Moderate Range in Southeast; Ozone Season Begins to Heat Up
The smoke in the Southeast that we have been following on the Blog continued today, keeping PM2.5 values in the Code Yellow (Moderate) range in much of the Southeast and Gulf Coast regions, as shown in the loop of PM2.5 AQI values (below on upper left, courtesy of AIRNow). The smoke is visible in today’s MODIS Terra true color image overlaid with AQI values (below on lower left, courtesy of UW MODIS Today and AIRNow), particularly in central Florida and the eastern Gulf of Mexico. The corresponding MODIS Terra AOD image for EPA Region 4 (below on lower right, courtesy of IDEA) indicates that AOD values were elevated due to the smoke.
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NOAA’s Hazard Mapping System (HMS) reported large swaths of smoke over the Pacific Northwest and Midwest, shown in the HMS map below. These plumes were not evident in the true color imagery, and they did not seem to significantly affect air quality at ground level.
Meteorological conditions (high pressure, sunny skies, light winds) are setting the stage for an ozone event across parts of the Midwest this week. Today, ozone levels were Moderate in much of the Midwest and California, with scattered areas of Code Orange (Unhealthy for Sensitive Groups), as shown in the loop of ozone AQI values (below on upper left, courtesy of AIRNow). The lower panels below show the forecasted AQI values for the nation for Wednesday. Air quality forecasters are predicting widespread Code Orange ozone levels tomorrow across the Midwest and southern California and Code Red (Unhealthy) conditions in Houston and Dallas-Fort Worth. These high ozone values will be concomitant with high temperatures and high humidity, so residents in affected areas should take appropriate precautions to protect themselves from the heat and poor air quality on Wednesday.
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