Words cannot do justice to the astounding event which opened the 2006-07 lake effect snow season. Not only was it the earliest named event by far (two weeks) of the over 120 in the 13 year record of the National Weather Service's lake effect archive, but it was the most unique in regards to destruction of trees and power outages, directly because of its out of season factor. Almost a million residents of the Niagara Frontier lost power, some for as long as a week, and tree damage was the worst in memory, especially to the lush vegetation in the many historic parkways and parks in the Buffalo area.
The extreme parameters of the event were noted all week and even mentioned six days ahead in forecast discussions. The depth of cold air was almost unprecedented for so early in the season and Lake Erie was a mild 62 degrees, three degrees above normal for October 12, and instability levels were dramatic with a 24C temperature difference between the surface and roughly 4000 feet! The only question, and it was a big one, was whether the lower atmosphere could be cold enough to maintain snow with a flow off a 62 degree lake. It was initially assumed that there would just enough moderation for the bulk of this forecasted intense lake effect storm to fall as rain, with perhaps some graupel or wet snow inland, but by Thursday morning (12th) it was becoming marginal, and a warning was issued by the National Weather Service early Thursday afternoon for 1-6" of wet snow, specifically because of the fact that most trees were still in full leaf, and the threat of serious damage and associated power outages.
The event began with lake effect rain during Thursday morning and midday, and enough cold air became entrained to change over the precipitation to wet snow in the Buffalo area by 3 pm. Still, little accumulation resulted for a few hours, but by 8-9 pm, reports of trees falling and power outages suddenly increased rapidly after 2-3" of snow, which was very wet and weighed down the trees. Conditions only worsened overnight with near constant thunder and lightning for a good 12 hours. Cloud tops reached an incredible 25-30 thousand feet, about double what had previously been observed in the worst events, and this was directly attributed to the phenomenal uplift over the 62 degree lake.
The heaviest snowband set up across Buffalo's northern suburbs Thursday evening, then drifted south into the southern suburbs around midnight, then lifted slightly to the city and eastern suburbs in the wee hours before lifting north across the northern suburbs again around daybreak and eventually to Niagara county Friday (13th) morning where it weakened and faded to rain.
Even though plenty of damage resulted already in the first few inches, total snowfall in this event was simply unbelievable. 5 to 8 inches fell in the first phase of the event between 3 pm and midnight, but the snow water equivalent (swe) ratio was around 6:1 or so, hence the terrific damage to trees and powerlines. The second phase featured slightly drier snow, maybe 12:1 but it piled up another foot in heaviest area, in just 4 hours or so. The 22.6 inches recorded at the Buffalo airport not only blew away any October record (6" in 1909, only 4 falls of 2" or more in 100 years in October), but was the 7th greatest snowfall ever at any time in Buffalo!