This is not going to be a record-breaking cold December, but my confidence remains high that much of the time between now and Christmas, and at least a little beyond Christmas, temperatures will be running below-average for this time of the year, and well below-average later next week. That again reinforces my confidence that most or all of Western New York will have at least a thin coating of snow on the ground Christmas morning, with much more on the ground in the hilly terrain.
You can run this regional sector of the GFS (NWS model) yourself, one panel at a time, or loop it. While no model is particularly reliable for placement and intensity of precipitation too far out in time (certainly beyond seven days), there is a pattern you may pick up on viewing the 384 hour run of this model:
The GFS brings areas of synoptic/widespread, non lake-effect snow with areas of low pressure going by to our south every few days. Each of those modest storm systems is followed by reinforcing surges of polar air. With each such surge, however, the low level flow will tend to be from the west and west-northwest, which is what steers most of the heavy lake-effect into the hilly terrain well south. That’s what’s been the case in the lake effect late this week. A west or WNW flow simply does not favor the metro area for any real lake-effect accumulation. (You can brush up on lake-effect basics, if you like, in my Lake-Effect Primer.
However, the modest synoptic snow from those low-pressure storm systems should stick around, due to the predominant cold pattern. The European model is putting 8 inches of snow down over the next 10 days at Buffalo, with nearly all of it synoptic rather than lake-effect. My best guesstimate is the vaunted European is running on the high side. The often maligned GFS gives Buffalo 4 inches and the Canadian brings 6 inches over the same period. (I can’t show the European precipitation, because that product is subscription based and strictly proprietary. I don’t have a lawyer retained to defend me and The Buffalo News in the lawsuit which would ensue.) But here is the Canadian output over the next 5 days which, again, allows you to animate.
I wrote in previous articles that below-average temperatures do not guarantee above-average snowfall for Buffalo precisely because we’ve had winters in which the cold was there, but the west-northwest flow was repetitive. As of now, there are no signs in either models or ensembles of any prolongedsouthwest flow cold periods. A wind from 250 degrees on the compass would tend to steer lake effect into Buffalo and out past the airport to Batavia (ensembles are multiple runs of given models, each with different start up conditions; the European ensemble has 51 ensemble members because of the superior computer crunch power at the European Centre in Reading, England, as opposed to the 21 member ensemble of the American GFS). The more common 270 to 310 degree flow we’ve been experiencing tends to leave Buffalo, as well as nearby metro area 'burbs, mostly high and dry.
Without fear of lawsuit, I CAN show European ensemble upper air flow over time here.
The “blue” of cold dominates, with the coldest of the cold staying in the northern plains and the upper Midwest, rather than our region. The same can be seen in the GFS ensemble, called GEFS: GEFS is in good agreement until around the 19th, when it warms the east up. The longer-range European ensemble doesn’t have much of a pre-Christmas warmup.
But IF the GFS/GEFS were correct, it’s conceivable my forecast of a White Christmas in and near the metro area could still be a bust. However, in this GFS precipitation ensemble output, Buffalo would receive more than 2 inches liquid equivalent by late Christmas Eve.
If I chose a very conservative 10:1 inch ratio of snow to liquid, that would mean more than 20 inches of snow by Christmas for Buffalo. In a colder regime as suggested, that could be 25-30 inches which, at this point, I feel is significantly overdone. But the European ensemble (the one I can’t show you, drat!) has about 12 inches at Buffalo by Christmas. Even though that could still be overdone, with the mostly cold pattern we come back to what I stated in my earlier article, and what I’ve restated here.
Even though current signs don’t point to much lake-effect snow near the metro area, the probabilities are still—in my view—higher than normal Buffalo climatology for a White Christmas, and a cold December.
But if you hate wintry weather, I can offer another ensemble I can’t show: The Japan Meteorological Agency ensemble has quite a warmup in the East developing in the first part of January. So is that something for you winter-haters? Yes, there’s your hope. And for those who ask “what the heck does the Japanese weather service know about U.S. weather?!”, I remind you the best global model most often for the U.S. is run in Reading, England. It may relieve you to know our excellent National Weather Service has full access to it to blend into the forecasting process. Insert smiley face here.