Climatology of surface cyclone trajectory and intensity for heavy-snow events at three midwestern stations

In this paper, we assess interstorm cyclone variations in intensity and mot ion for heavy-snow events at three north-central U.S. stations: Minneapolis , Madison, and Indianapolis. Daily data for the period from 1966 to 1996 we re used to select the 157 storm events. Heavy-snow cyclone track location ( latitude and longitude) and intensity (central pressure) means and standard deviations are calculated for each station and related to snowfall magnitu de. The most northwesterly of the three stations, Minneapolis, had the larg est median heavy-snowfall total and also the largest standard deviation in heavy-snowfall amount. Statistical analysis of surface cyclone parameters r eveals significant interstation differences in storm trajectory and intensi ty measures for all cyclones and cyclogenesis group subsets. Chi-square tes ts suggest that the distribution of storms by month and cyclogenesis type i s significantly nonrandom for ail stations. Summary findings indicate that Midwestern heavy-snow events are dominated by southern Great Plains cyclone s and that storms from secondary cyclogenic regions contribute to significa nt differences at the three selected locations.