No doubt there are those who would just as soon skip the whole snow scene. But even some of those die-hard winter haters would like to see at least a thin veneer of snow on the ground for Christmas morning, just for scenery and atmosphere.
Statistically, Western New York has a higher probability of a white Christmas than much of the country over the years. The Christmas day climatology based on several decades of observed accumulated snow of at least 1” across the lower 48 tells us so.
Climatology is handy as a baseline. It doesn’t, however, tell us much what our chances are THIS year. After all, we have had a fair number of snowless Christmas days in recent years, and this year — as of this writing — Buffalo has had officially only 1.2” accumulated snow when we typically would have already had just under a foot. We are green and brown, decidedly so, for the time being.
Despite the current snow drought, I believe our chances this year will at least match climatology and possibly exceed it. Here’s why: We are heading into a wintrier pattern in which we will have more days with temperatures running below average for this time of the year most (not all) days well into the month, if not for the rest of the month. If I’m correct in this prediction, this will be markedly different from last year’s warm and nearly snowless December. Colder temperatures do not guarantee above-average snowfall, but they do help preserve whatever snow we get.
This week, we’ll be facing some hefty lake-effect snow later on Thursday into Friday evening. Much of the time, the low level winds from the WNW will favor the majority of that snow falling away from the metro area and mainly on the hills well south and also well northeast of the metro area, courtesy of a Lake Huron connection. The WNW flow usually distributes snow as depicted in this model graphic.
But this is not to say the winds will run from WNW through the entire event. There may be some backing to WSW for a time, and the Lake Huron hookup may also meander into the metro area for short periods as well. Because this will be the coldest air mass so far, the intensity of the lake effect will often exceed what we had two Sundays ago.
In the longer range, the ensemble/multiple runs of the European model do show more frequent episodes of colder-than-average temperatures and the potential for some rounds of both lake-effect snow and some occasional widespread snow. The American GFS model joins in on this trend as well.
The European ensemble of the upper level flow (an ensemble is made up of multiple runs of a model, each with slightly different initial conditions due to the uncertainty of those precise conditions. The European Centre has the greatest computer crunch power in the world, and runs 51 ensemble members, giving us a greater range and perspective over time). Click here for the ensemble projection of the upper air pattern next midweek.
I’m hoping that even unfamiliar eyeballs can see the cold “look” to that flow. What is happening in stages is that some of what had been incredibly cold air in Siberia is now beginning to leak across the pole into western Canada and the U.S., and will be reaching us in modified form in the Great Lakes.
Again, it’s not going to be colder than average every single day until Christmas. But it will be colder more often for more of the time, and there will be more opportunities for both lake effect and more widespread snow. So, I’m leaning toward probabilities of a white Christmas being up to 10 percent higher than our already pretty favorable climatology. The ski resorts should be in pretty fine shape (especially by the end of this week), and some road crews are going to have their work cut out for them a lot more than they did last year at this time.