Flash Flooding and Flood in Massachusetts, December 17 to 18, 2000

A complex storm system began to evolve on Saturday December 16 across the Mississippi Valley. A surface low tracked north into the Eastern Great Lakes by December 17. At the same time, the associated upper level trough became negatively tilted as it moved toward the northeast on Sunday. This allowed for rapid cyclogenesis. Unseasonably warm and moist air was transported northward from the Gulf of Mexico. This scenario brought a record breaking rainstorm to Western Massachussetts. At the same time, the airmass became unstable enough for widepsread thunderstorm development. There were very strong winds aloft. Two of the storms transported those strong winds to the surface, and became severe. One storm produced downed wires in the towns of Pittsfield and Berkshire. In addition, tree limbs were blown down and spotty power outages took place. About two hours later, winds from another severe thunderstorm blew more trees down in the town of Berkshire The bigger problem was the heavy rainfall. Rainfall amounts were in the 2 to 4 inch range, with Dalton receiving 2.44 and Great Barrington 3.87 inches, respectively. The bulk of the rainfall was in a short interval of time, with some localites receiving an inch per hour. The excessive rainfall combined with melting snow and frozen ground, to produce massive runoff. Streets were flooded in the town of Berkshire. In Pittsfield, flooding was reported at the intersection of Lincoln and 4th Avenue. Roads were also flooded around Pittsfield Airport. The Williams River swelled just over its 6-foot flood stage at New Boston.