The prediction of fog occurrence, extent,
duration, and intensity remains difficult despite improvements in numerical
guidance and modeling of the fog phenomenon. This is because of the dependency
of fog on microphysical and mesoscale processes that act within the boundary
layer and that, in turn, are forced by the prevailing synoptic regime. Given
existing and new technologies and techniques already available to the operational
forecaster, fog prediction may be improved by the development and application
of a simple conceptual model. A preliminary attempt at such a model is presented
for the southern region of the United States (gulf coastal states) and requires
information regarding cloud condensation nuclei, moisture availability (or
saturation), and dynamic forcing. Each of these factors are assessed with
regard to their extent and evolution with time. An illustration, and potential
application, of how the model could be used is detailed as no extensive operational
testing has yet been completed. Instead, the model is applied in hindcast
to verify its application. Successful use of the model will require an operational
forecaster to assimilate all available tools including climatology, numerical
guidance, sounding analysis, model diagnostic software, and satellite imagery.
These must be used to characterize and quantify the nature of the local and
regional boundary layer in the forecast region according to macroscale forcing
and moisture availability, the initial local settings and boundary layer,
qualitative assessment of cloud condensation nuclei, and the interaction of
these in time and space. Once identified, the evolution of the boundary layer
may be forecast with regard to the overall environment for fog occurrence,
its likely extent, intensity, and duration.
National Weather Service
Mobile/Pensacola Weather Forecast Office
(251) 633-6443
sr-mob.webmaster@noaa.gov
Page last modified: June 3, 2005 |
Disclaimer |
Privacy Policy |
www.srh.weather.gov 
