Fog sequences on the central California coast with examples

In the low visibility range, forecasts during the summer period along the west coast of California are presently not made with any degree of accuracy. Modeling sequences associated with the nonfrontal fog formations during the summer period offer the possibility of improving fog diagnosis. Such sequences have been in use in Southern California for some time. This study uses a synoptic approach, focusing on sequences observed in the non-diurnal aspects of coastal fog. A development model is presented in order to delineate patterns of the fog phenomenon along the Central California coast. Actually observed fog situations are presented in order to evaluate the model and determine if day-to-day changes in specific non-diurnal indices represent trends which can aid forecasters. Results show that, although the model is general in nature, a correlation between the stages of the observed fog exists. The relationship of the time of occurrence of dense fog and the trends in the height of the inversion base and daily maximum temperatures at the top of the inversion and the inland valley are pointed out. (Author).