Analysis of the Structure of Precipitation Patterns in New England

The studies presented here were undertaken to provide a specific and quantitative description of the precipitation patterns in New England storms. Basic data were quantitative radar observations and detailed raingage records. Nine storms covering a wide range of synoptic and seasonal situations were subjected to systematic analysis. Also the general shape and configuration of the mesoscale rain areas in seventeen fully developed cyclones were observed. The precipitation patterns, which at first glance appeared very dissimilar, out to be composed of subsynoptic-scale precipitation areas with rather clearly definable characteristics and behavior. Four distinct scales of precipitation areas have been recognized and described: synoptic arms which are larger that 104 km2 and have a lifetime of one or several days; large mesoscale areas which range from 103–104 km2 and last several hours; mesoscale areas which cover 100–400 km2 and last about an hour; and cells which are roughly 10 km2 and often last o...