Relationship of Precipitation to Vorticity and Vertical Motion at Salt Lake City, Utah

An empirical study was made of the relationship of precipitation occurrence t o linearly interpolated concurrent vertical motion, 500-mb. initial 1-orticity, vorticity advection, and the average of the 700-mb. and 500-mb. dew point depressions a t Salt Lake City, Utah. All parameters except dew point depressions were obtained from the facsimile charts transmitted by the National Meteorological Center a t Suitland, Md. Correlation between the three NMC computed parameters and observed precipitation was riot as good as the correlation between dew point depression and precipitation. However, initial vorticity combined with rorticity advection resulted in a much better correlation with precipitation occurrence than did either parameter alone.