As we watch the flakes fall tonight, it’s certainly making things look more like Christmas around here. December 25th arrives Friday of next week, and we’re still too early in the game to provide any sort of a detailed forecast rooted in science. But, we’re now at a point where we can peel back the curtain on the overall pattern, and what such a pattern could do for us by Christmas day.
Christmas in Rochester has historically featured a mixed bag of weather. We had 18″ of snow on Christmas in 1978. Two years later, we were -12 degrees on Christmas morning, 1980. Two years after that, Rochester was 66 degrees on Christmas Day. Go figure. On average, Rochester will see at least a trace of snow either 1) falling or 2) on the ground roughly 80% of the time. Those numbers drop to 57% if you’re looking for at least an inch on the ground. Essentially, we have a better than coin flips chance of a white Christmas on any given year.
WHAT ABOUT THIS YEAR? I’d be inclined to suggest those 57% odds are even higher this year. The pattern certainly seems to support the idea of a chunk of cold air parked across the Great Lakes.
Both Euro & GFS ensembles are remarkably similar in the notion of a trough/colder air becoming established across our general vicinity. Some 9 days out, it’s striking how similar these two are. That adds an extra layer of confidence to the forecast. Such a setup would imply temperatures largely below normal, half the battle in our quest for a white Christmas. To be clear, patterns like this can come in two flavors. Cold and dry, & cold and snowy. It’s too soon to know which camp this will fall into. First blush, this looks like we go from a brief warmup prior to Christmas to a quick reversal toward colder. I’d expect at least some snow to be in there, but this has the early feel to me that we might need to rely on Lake Ontario to get us some white stuff, so if you live in the snowbelt, you might be in luck.
For now, white Christmas lovers, our gift to you is what appears to be evidence our chances of “feeling” like Christmas are increasing. Stay tuned.
Chief Meteorologist Eric Snitil