Climatological-synoptic patterns associated with North Atlantic tropical cyclogenesis

Abstract

Several groups of North Atlantic tropical cyclogenetic situations were selected and composites of the associated synoptic patterns were developed. Each group was made as internally homogeneous as possible with respect to seasonal time and geographic location of cyclogenesis. A deliberate effort was made to obtain hetero-geneity between groups and homogeneity within groups. Composite patterns of surface pressure, 500 mb. height and temperature, divergence and vorticity at these levels and surface to 500 mb. thickness were developed for the groups of storm origins selected. Similar groups of dates on which no storm development occurred were studied in the -same manner. Comparisons are made between genetic and non-genetic patterns for several genetic areas and several parts of the storm season.