After a very quiet and late start to the 2001-2002 snow season with only one moderate snowfall in early December, 2001, a fast moving combination of a major Nor'easter and secondary upper level storm combined to produce significant snows in a very narrow axis across upstate New York and parts of New England.
Typically, but not always, major east coast snow storms are formed when two branches of the jet stream come together to form a large energetic upper level storm, that when it intersects the strong temperature gradient formed by the warm Atlantic ocean, creates a surface storm that tracks up the coast to bury the Northeast with heavy snow. In this case, the northern and southern stream branches of the jet never really phased well. What happened instead was that a strong upper level storm embedded within the southern branch of the jet intensified to the point, as it drove south into the Gulf of Mexico, that it alone was able to buck a fast shearing flow along the coast as it swung around the base of the east coast trough, to form a moderately intense surface Nor'easter that produced some heavy snow in the Northeast. The storm did move very rapidly from off the Virginia coast late Sunday afternoon to the Canadian Maritimes by early Monday morning, which reduced the amount of snow that would have fallen had the system moved slower.
The fast speed of the storm, however, was compensated for by the lift in the atmosphere the storm created and the high moisture content of the air it brought with it from the Gulf of Mexico. The atmospheric lift was so great and moisture content so rich that snow fell at rates of 2"-4" per hour for a couple of hours from 8pm through midnight on the 6th. In fact, at Albany, eight inches of snow fell between 10:00pm and midnight on January 6.
The storm was difficult to forecast because of the fast flow present along the eastern seaboard. Typically, patterns where the flow is very fast up the coast tend to shear developing surface storms which prevents significant intensification. The flow in this case, as late as 24 hours prior to the storm's arrival, also suggested a track that would take it about 75 miles southeast of Cap Cod which would have put the immediate Capital Region on the northern fringe. It became apparent during the morning of the 6th that the storm would intensify enough to buck the shearing flow and track closer to the coast bringing heavier snow further north. As it turned out the band of very heavy snow, 14"-20" fell in a very narrow axis that extended from Delaware county through much of Schoharie, Greene, Albany, southern Schenectady, southern Saratoga, northern Rensselaer, southern Washington counties in New York, all of Bennington, and extreme southern Rutland counties in Vermont. A short distance north and south of this snow band accumulations dropped off considerably to between three and nine inches. The difficulty in determining that a band of snow so heavy and yet so narrow will develop in any storm is considerable.
Snow began in Albany at approximately 7pm and by midnight had accumulated to 12.7" for a new 24 hour snowfall record for January 6. Snow became much lighter and generally ended by 3:00am across most of the region as the low rocketed to the Northeast.
Light snows fired up again in association with a second, much weaker upper level low pressure system Monday morning the 7th and continued much of the day. Additional accumulations throughout all of eastern New York and western New England ranged from two to four inches on the 7th. The grand total at Albany from the two systems was 17.4" which made this the 5th heaviest January snowstorm on record.
The following table lists area snow accumulations as reported by the exclusive Channel 6 WeatherNet 6 weather watcher network. Notice the extreme variability in the snow accumulations. Snow amounts in the Adirondacks to Lake George ranged from 2"-5" and from 4"-9" in the Mohawk valley to northern Saratoga county. 4"-9" of snow was also observed in the mid Hudson valley, to Berkshire and Litchfield counties in western New England. 14"-20" of snow fell in the narrow zone between the Adirondacks and the mid Hudson valley.