Satellite data clear fog from forecasts

Researchers from the Cooperative Institute for Meteorological Satellite Studies are investigating the possibility of using water vapor and cloud observations from the GOES-12 weather satellite to improve the prediction of fog above Wisconsin roadways.

Three-layer precipitable water and cloud-top pressure retrievals from the GOES-12 sounder are being assimilated into the 20-km resolution CIMSS Regional Assimilation System. Thirty-six-hour forecast time series are being generated for instrumented sites of the Wisconsin Department of Transportation, which will be used to validate fog forecasts.

The CIMSS Regional Assimilation System is particularly suited to this task because it is designed to accurately predict the movement of water vapor in the atmosphere. Among the next steps is a surface visibility product that will show areas of fog. Until then, fog must be deduced from relative humidity and other satellite products.

Bob Aune, a National Oceanic and Atmospheric Administration scientist at UW–Madison’s Space Science and Engineering Center, is encouraged by results for a recent fog event.

Demonstrating that information from satellites can be used locally to improve numerical weather forecasts, Aune presented his CIMSS Regional Assimilation System modeling work at recent workshops held by the U. S. Weather Research Program in Boulder, Colo.