On the evening of October 12-13, 2006 Buffalo, NY was hit by a snowstorm of historic proportions.  The Buffalo airport recorded 22.6 inches of snow in a period of 14 hours.  22 inches of snow is a lot, but that alone isn't really enough to classify this as a historic storm.  What pushed this one into new territory was how early the storm came in the season.  Typically, snow storms this early in the season drop a lot less snow...maybe a couple of inches tops.  There have been exactly 4 storms to drop over 2 inches of snow in Buffalo during the month of October in the past 100 years, and the previous record was only 6 inches of accumulation.   According to meteorologists working for the National Weather Service at KBUF, the city has never had a snowfall like this before November 20th of any recorded year.  I happened to be about 90 minutes away (in Rochester), where we only got a few flurries.  There I was able to keep a pretty close eye on the storm.

The storm system coming in was forecasted a few days earlier.  An upper level trough was moving across the continental U.S., and a pretty big upper level low was starting to form.  The system slowed down when the low was near Lake Superior and the pressure really bombed.  I have one surface map marking a 976mb low pressure center, and I believe the pressure dropped slightly after that image was rendered.

The day before the snow started, I was driving from Michigan to NY.  At that point, the cold front hadn't come through yet, and we were being hit with a ton of rain.  That evening when I arrived, it was quite warm outside, as a warm front had just passed through.  It was around 60F late in the evening, which is pretty warm for this time of year.  We were in the warm, dry sector of the storm for the next 12-24 hours, and had only a few occasional showers and it was generally pretty calm.  At noon on the 12th, temperatures were in the 50s, by 6pm the cold front came through and temperature was at freezing.  

Now, if you've never lived somewhere that has lake-effect snow, you probably don't know how it all works.  In the Great Lakes region, the eastern and sometimes southern coasts of any given lake will get hit with a lot more snow than other areas.  This happens with the lake is a lot warmer than air about 1-2 km above the surface.  With warm moist air at the surface, and cold air aloft, a lot of air will rise to form clouds.  The clouds build up over the lakes and it starts to snow, hitting the coastal areas and sometimes continuing a hundred miles inland or more.  Lake-effect regions also get more rain in the summer time, but it's most pronounced in the early winter when the temperature difference between the lake and the atmosphere is greatest.

Since it was so early in the season, the temperature of Lake Erie was still 62F.  The upper air of this storm after the cold front came through was much colder, only around 20F.  This allowed rapid cloud formation from convection, and cloud tops of over 20k feet which are rare in a winter storm.  To add to this, there were excellent dynamics aloft.  Check out this vorticity map showing both the pressure and wind speeds up at the 500mb height:



This storm brought a lot of snow to parts of Michigan's upper peninsula and Canada as well, but Buffalo's situation was more dire.  The problem in Buffalo was that all the leaves were still on the trees, so snow was gathering on the trees and weighing them down.  The shear weight brought down several trees, branches, and power lines.  Reports came in of up to 300,000 people without power.  Several roads were impassible, and many were trapped at home without power, which can be uncomfortable in the winter.  Generators were sold out at every Home Depot and Lowes location within 150 miles, as power was expected to be off for a week or longer in some areas.

I went into the city to visit some family a couple of days later, and took these pictures while I was there.  It warmed up pretty quickly during the following days, so most of the snow was already gone by this point...



Some branches 6-8 inches thick were just snapped like twigs.  If you look closely at the second shot, you can see a power line just dangling from the utility pole.  One of those branches took it out in the middle of the night, and it was laying under a bunch of snow.  While driving in the city, I saw several power lines hanging pretty low above the roads, just hoping they wouldn't drop as I was passing under them.  It was pretty amazing.  

In the end, I don't believe there were any major injuries or casualties, which is good.  I'm sure they are still cleaning up the city even now that it is days later.  I imagine locals will be telling stories about "the storm of 2006" for years to come.