The Genesee Valley Blizzard of 4 March 1999: An Analysis Of Forcing Mechanisms

On March 4, 1999, a blizzard produced more than 24 inches of snow in the Genesee Valley region, which includes the metropolitan area of Rochester, NY. Although heavy snowfall is part of the winter ‘landscape' of this region, this storm paralyzed the residents of the area, because nearly all the snow fell within a six-hour period centered around 1200 UTC. At this time, a strong surface low located to the southeast of the Genesee Valley rendered Rochester and the surrounding areas an ideal location for receiving heavy snowfall. Although western New York is better equipped to handle heavy snowfall than most other places in the country, a failure to adequately forecast the snowfall amount and intensity left local government officials and residents unprepared to cope with a dangerous situation, which left thousands of motorists stranded on local roadways.

In order to gain a better understanding of the factors that contributed to the heavy snowfall associated with this winter extratropical cyclone, we analyze the synoptic and mesoscale aspects of the storm. Specifically, we

(i) elucidate the quasigeostrophic forcing (ii) examine the relationship between frontogenesis and snowfall distribution; and (iii) study the role, if any, of Lake Ontario in enhancing snowfall.

The primary source of data for studying synoptic conditions associated with the storm is the operational analyses produced by the National Centers for Environmental Prediction (NCEP). To perform two-dimensional frontogenesis analyses, operational products will be interpolated to a finer grid. For quantifying the contribution of Lake Ontario to the observed snowfall, the Pennsylvania State University-NCAR Mesoscale Model will be used to simulate the 4 March 1999 blizzard, with and without the lake.