Radar characteristics of storms in the Sydney area

The characteristics of radar echoes for 12 thunderstorm days in the vicinit y of Sydney,Australia, in the summer of 1995/96 have been examined using an objective methodology for storm identification and tracking. The spatial d istribution of identified storms shows a maximum in frequency and intensity along the east side of the mountains that lie inland from the coast. Chara cteristics such as storm volume, area, and height are shown to have a logno rmal frequency distribution. Reflectivity also has a skewed frequency distr ibution with a prevalence of lower reflectivity storms. Both the maximum re flectivity and storm height are shown to be correlated with the logarithm o f storm volume. Although small storms predominate, the bulk of precipitatio n flux comes from the relatively few fare-scale storms. It is also shown th at storms generally move or propagate in a direction slightly to the left o f the mass-weighted mean wind for the surface-to-300-hPa layer at a speed s lightly less than the mean speed. Furthermore the deviation of the storm to the left of the mean layer wind increases and the standard deviation decre ases as the storm size increases.