Long Duration Severe Nor'easter
From the initial computer model suggestions eight days prior to the storm, it was clear that there would be nothing typical or usual about this nor'easter. The atmospheric stage was being set with three main weather players. The first player, interestingly enough, was a large upper level high pressure system locked in place over Greenland and the north Atlantic. This high pressure system essentially acted to block traffic in the atmosphere causing weather systems to either stall or backup over North America. The second player was a large upper level low pressure system that formed over southeast Canada the week prior to the storm, delivering a supply of cold air to the Northeast. The final player in the evolution of this long duration nor'easter, was a powerful sub tropical jet stream that contained a series of strong disturbances and copious moisture.
The storm generation process began early in the week preceding the event as a series of strong upper air low pressure systems running in the sub tropical jet stream pulled moisture north from the Gulf of Mexico. Late in the day Saturday, March 3, a strong surface low pressure system developed from the energy in the sub tropical jet over Louisiana. Concurrent with the development of the surface storm, the block in the atmosphere over Greenland was forcing the upper level low pressure system north of New England westward towards the Great Lakes. The westward motion of the upper low allowed southwest flow to develop along the Atlantic seaboard. The southwest steering flow enabled the Louisiana storm to track through the southeast on Sunday, March 4 and redevelop along the North Carolina coast by 7pm Sunday. Overrunning, due to the developing counterclockwise flow around the storm on the coast, caused the first snow flakes to fly in eastern New York and western New England late in the afternoon and early in the evening of the 4th. Light to at times moderate snow fell over mainly New York, from the Capital Region and Catskills on westward through the night. General accumulations by Monday morning, ranged from 2"-6".
By 7am Monday morning, March 5, a storm of only moderate intensity was located east of the Delmarva peninsula. Packets of light snow or mixed light snow, sleet, and freezing rain came in fits and bursts through the day as the slowly strengthening storm pushed moisture into the Northeast. Explosive intensification did not occur until the evening, when the powerful upper level low pressure system, forced west to Michigan, began dropping southeast into the mid Atlantic, where it energized the developing coastal storm. The upper level low pressure system also caught the storm, pulled it into the coast, and held it there almost stationary for about eight hours during the evening and early nighttime hours on the 5th. The combination of the coastal storm's nearly stationary position and rapid intensification created a rapidly expanding snow shield over New England. The strong easterly flow which developed as a direct response to the storm winding up, pushed the snow shield from east to west through New England and into New York. Heavy snow pasted most of eastern New York and New England from 11:00 pm on the 5th through daybreak on the 6th. Snowfall rates occasionally exceeded two inches per hour. And, in a thirty to forty mile wide band of convective snow, responsible for lightning and thunder in Vermont, that moved across northern Berkshire county, the Capital District, eastern Mohawk valley and points north, snowfall rates ranged from two to four inches per hour from 11:00 pm to 3:00am. By the early morning on the 6th, much of the area was buried under 15"-25" of snow, with the snow still falling.
On Tuesday, March 7, the storm tracked west along the southern New England coast and then during the evening, it turned south. The circulation weakened and the moisture supply dwindled which allowed the concentrated snow shield over New York and New England to break up and become less intense throughout the day. With the exception of scattered flurries, the snowstorm ended by 11:00 pm on Tuesday March 7, approximately 27 hours after it had begun.
During the storm's peak, winds along Cape Cod and the Islands gusted between 50 and 60 mph, and near Blizzard conditions developed in northeast Massachusetts. Wind, however, in New York and western New England was not much of a factor. Winds did gust to 30 mph during the afternoon and evening of the 6th, but only caused a minimum of blowing and drifting snow. Temperatures remained in the mid 20's through the storm's duration locally, which yielded a fairly light, powdery snow.
During the first phase, Sunday night through Monday, snowfall was somewhat intermittent and the rates were generally under 1/2" per hour. Road crews had little trouble keeping up with the accumulating snow. Most schools and businesses including the malls closed early in the day, so traffic was light and few problems were reported. The peak of the storm, came as forecast, during the overnight period, when most people were sleeping and not on the roads, which allowed crews to rather effectively clear the streets despite the blinding snowfall rates that occurred.
The following table lists snow accumulations reported by the Channel 6 WeatherNet 6 weather watcher network as well as some reports from the National Weather Service Cooperative network of weather observers.