It was pretty clear by about noon yesterday I had screwed this one up. While the track of the low pressure to our south was pretty much locked in for the 72 hours leading up to the snow our models woefully underestimated the strength of the cold, dry high pressure to the north. And that was just the beginning of their failures. Each successive set of model runs came in colder and colder and colder. By the time the snow started it was so dry (and therefore cold thanks to evaporative cooling) that it barely even snowed in the Connecticut River Valley in Massachusetts.
On this 15z surface map you can see just how darn dry it was over northern New England with dew points in the single digits and teens. With a slow moving storm to the south of us the northerly ageostrophic wind ripped the dry air south through the valley and across all of southern New England. This served to shut off the snow around Northampton and Springfield and provide enough evaporational cooling to keep places like New Haven and Bridgeport snow.
Not going to get much snow with a sounding like that, especially given a steady supply of super dry air to the north. Early on it became apparent that this was going to be snow, the question was just how much snow would we see?
It was a bizarre storm in that every aspect of it overperformed in the snow department. The mesoscale bands wound up a bit more powerful than forecasted thanks to a variety of factors including instability that promoted convection in the snow growth zone.
In many storms like this, with an early maturation and occlusion to our south, we get a sloppy set of disorganized bands that rarely amount to much. Especially when temperatures, at one point, looked marginal at best.
So what’s done is done. The forecast was a bust. The storm was a tough one to forecast with busts all over the northeast (Philly, for instance, was under a winter storm warning and they recorded a trace).
This snowstorm was record breaking. In Bridgeport 8.3″ of snow fell making this the greatest single snowstorm in November history. Bridgeport has also managed to break the record for snowiest November in history. A snowstorm like this is hard to do on the shoreline in November! The previous record holder was the 1989 Thanksgiving snowstorm which happens to be my 2nd earliest weather memory (July 10, 1989 tornado being the first). The greatest October and November snows have occurred in 2011 and 2012, respectively. What we’ve lacked in March snow recently we’ve made up for in early snow.
A lot of people have asked if we can think of anything as wild as the last 2 weeks – going from a hurricane to a record snowstorm. The only thing I can think of that comes close is October 1979 which saw an F4 tornado on October 3rd and the first measurable snow on record on October 10th. It’s a bizarre clash of the seasons to be sure.