1. INTRODUCTION
Buffalo, New York was paralyzed on 9-10 December 1995 when the airport measured 38 in. of snow in a 24-hour period. This amount shattered the previous 24-hour snowfall record of 25.3 in. set on 10-11 January 1982. This event was the result of periods of intense snow produced by a single but stationary lake effect snow band that formed over Lake Erie.
The purposes of this case study are to identify, analyze, and discuss the atmospheric state that produced the record snowfall. Because lake effect snowstorms are mesoscale phenomena, an emphasis will be placed on the crucial mesoscale processes operating during the event. Also, with the data presented, a hypothesis will be given to explain why this event was so extraordinary. These purposes will be accomplished by an overview of lake effect snowstorms followed by a summary of the weather conditions during the snow storm based on transmitted surface observations. Next, the discussion will be divided into three discrete time sections based on their meteorological significance. In each of these periods, the synoptic and mesoscale situation will be presented using surface data, satellite imagery, and radar imagery to identify the location, evolution, and movement of the snow band. Finally, because Buffalo is an upper air station, the upper air data presented has enabled this case to be analyzed with finer detail and greater accuracy.
A classic Type I snow band is illustrated in the base reflectivity display for 1418 UTC 10 December 1995 from the Buffalo WSR-88D Doppler radar. This imagery is from the period of heaviest snow and displays very high reflectivities (> 35 dBZ) for a lake effect snow case extending from eastern Lake Erie northeastward across the radar site at Buffalo.
The base velocity image for 1302 UTC 10 December 1995 shows a distinct zone of reduced radial velocities associated with this classic Type I snow band over Lake Erie. The reduced velocities are attributed to convergence of flow into the band and the possibility that lower momentum air is being advected upward from the surface layer by updrafts in the convection.
