| These are pictures from our photo archive to illustrate different weather conditions. The time when the picture was taken and the air quality for that day are shown for each picture. Ozone values are shown for the May through September photos as an 8 hr average. Fine Particulates are shown in all photo descriptions as a 24 hr average from midnight to midnight for that day. The daily color code for that day is also listed. |
| Clean | Strong Inversion |
 |  |
| A clean day with excellent visibility over the Blue Ridge mountains. February 12, 2003 at 4:16pm with an AQI reading of 23 (GREEN) | A strong inversion traps pollutants close to the surface. The dark color of this layer is due to the forward scattering of sunlight by the pollutants in the layer. December 30, 2002 at 11:16am with an AQI reading of 65 (YELLOW) |
| | |
| Classic Inversion | Rain Showers Moderate Air Quality |
 |  |
| Classic Inversion under the top of Pilot Mountain which has a elevation of 2421 feet above sea level. Notice the snow cover on the ground and the deep blue sky above the inversion. This inversion is located at about 1800 ft. as confirmed by that day's sounding. December 7, 2002 at 2:45pm with an AQI reading of 74 (YELLOW) | Rain showers envelope the Triad but air quality remains in the Yellow range. It is very common for fine particulates to be unaffected by precipitation for the first 6-12 hours of an event. October 24, 2002 at 12:15pm with an AQI reading of 61 (YELLOW) |
| | |
| Moderate Air Quality | Sunset Good Air Quality |
 |  |
| Typical moderate air quality day with Pilot Mountain reduced to a silhouette. Notice the milky appearance of the haze throughout the picture. November 19, 2002 at 1:15pm with an AQI reading of 63 (YELLOW) | A beautiful shot of a sunset behind Pilot Mountain. The sun looks to be triple its normal size due to refraction of light as it slides behind the clouds. February 13, 2003 at 5:45pm with an AQI reading of 22 (GREEN) |
| | |
| Moderate Air Quality | |
 |  |
| Moderate air quality day in the summer season with Ozone being the dominant pollutant. This day was preceeded by three straight ORANGE days. July 19, 2002 at 3:45pm with an AQI reading of 56 (YELLOW) for ozone and 42 (GREEN) for fine particulates. |
| | |
| Unhealthy Air Quality | |
 |  |
| Unhealthy air quality day in the summer season with Ozone being the dominant pollutant. This day was a fabled "DOUBLE ORANGE" day of a three day event where both pollutants reach the Orange level. July 17,2002 at 2:45pm with an AQI reading of 137 (ORANGE) for ozone and 102 (ORANGE) for fine particulates. |
| | |
