MODIS Fog Product Pinpoints Valley Fog in East Tennessee

The 1km MODIS Fog Product overlaid with a high-resolution topographic image shows the formation of fog in valleys and near bodies of water across East Tennessee and Southwest Virginia.

The image above demonstrates the outstanding ability of the 1km MODIS Fog Product to depict valley fog. The topography of East Tennessee and Southwest Virginia is quite complex, with numerous small lakes, rivers, and valleys. In the early morning hours of September 8, dense fog formed across many of the valleys and rivers of the area. The MODIS Fog Product allowed forecasters to see fog developing along the Big South Fork of the Cumberland River, the Powell River, the Clinch River, and the Holston River. Without the 1km resolution of MODIS, the extent of the dense fog would have been virtually impossible to detect. Although the fog was not widespread enough to warrant a Dense Fog Advisory, the following Nowcast was issued:

.NOW...
THROUGH 9 AM EDT...PATCHY DENSE FOG WILL AFFECT PORTIONS OF
NORTHEAST TENNESSEE AND EXTREME SOUTHWEST VIRGINIA. THE WORST
AREAS WILL BE PLACES CLOSE TO WATER, AND OPEN AREAS. PLEASE BE
CAREFUL WHEN DRIVING AS VISIBILITY WILL DROP TO NEAR ZERO VERY
QUICKLY. THESE CONDITIONS WILL REMAIN UNTIL AFTER SUNRISE.