Abstract
An empirical study was made of the relationship of precipitation occurrence to linearly interpolated concurrent vertical motion, 500-mb. initial vorticity, vorticity advection, and the average of the 700-mb. and 500-mb. dew point depressions at Salt Lake City, Utah. All parameters except dew point depressions were obtained from the facsimile charts transmitted by the National Meteorological Center at Suitland, Md. Correlation between the three NMC computed parameters and observed precipitation was not as good as the correlation between dew point depression and precipitation. However, initial vorticity combined with vorticity advection resulted in a much better correlation with precipitation occurrence than did either parameter alone.
