NUMERICAL FORECASTING OF RADIATION FOG .2. A COMPARISON OF MODEL SIMULATION WITH SEVERAL OBSERVED FOG EVENTS

A ID model adapted for forecasting the formation and development of fo g, and forced with mesoscale parameters derived from a 3D limited-area model, was used to simulate three fog event observations made during the Lille 88 campaign. The model simulation correctly reproduced the t ime of fog formation and its vertical development when forcing terms d erived from observations were used. It determined the influence of dif ferent physical processes and in particular that of dew deposition. Th e initial conditions deduced from the 3D model proved to be correct in two of the three events. On the other hand, the prediction of advecti on terms necessary for forecasting the vertical growth of fog was a mo re delicate matter.