Snow for Christmas? Don’t get your hopes up

Christmas is a week out and the big day is starting to come into the range where we can take a serious stab at a snow forecast. I hate to be the bearer of bad news, but chances for a White Christmas in east-central Ohio this year is looking pretty slim. I’ll explain.

First, for those who may not know, there is an official definition for the term White Christmas. Most agree that a White Christmas means one-inch of snow on the ground Christmas morning. The definition doesn’t say anything about it being old snow that may have fallen days ahead or new snow that might fall on Christmas Day. It just states one-inch (or more) of snow on the ground.

As far as I’m concerned, ANY snow on Christmas makes it a White Christmas. But that’s just me.

THIS YEAR’S CHRISTMAS WEATHER SETUP
Tuesday (the 18th) and Wednesday (19th) will be dry across the region and high pressure will bring periods of sunshine. Our weather situation will change toward the end of the week as a strengthening low-pressure system moves out of the southern Plains and travels into the Ohio Valley Thursday night. Odds for rain in our area will gradually increase through the day Thursday. Friday will be pretty much a washout.

As the system continues to travel to the northeast on Saturday, gusty northwest winds will bring colder air rushing in. We may see a short period of snow showers during the morning hours Saturday. (Pre-Christmas snow??) Temperatures will warm above freezing by the afternoon and any lingering precipitation will change back to rain. Generally speaking, odds for precipitation will diminish as we go through the day.

We may get a coating to a half inch of wet snow Saturday morning. But any snow that accumulates will be inconsequential and most will likely melt as we change over to rain.

CHRISTMAS WEEK
Sunday looks dry as the low continues pulling off to New England. snow showers on Sunday will be confined to the lake and snow belt counties. A weak cold front crosses the region Sunday night but it’s moisture-starved. High pressure will return on Christmas Eve with dry conditions and periods of sunshine.

High pressure looks to linger into Christmas Day which means it should be a fairly sunny, although a typically chilly early winter day. With dry air in place under high pressure, snow will be nearly impossible here. Temperatures on Christmas look pretty close to average – 36°/38°.

If you insist on snow for Christmas Day, a weak clipper system will cross the upper Great Lakes area. There are differences in the modeling on the southerly track of this system. The European model has the clipper a bit farther south than the GFS shown here. That may bring a little snow to the extreme northern Ohio and snow belt counties. Again, depending on how far south the clipper tracks as it travels eastward.

European (ECMWF) model thinking on snow from a clipper system Christmas night. The Canadian model agrees. The GFS depicts the system crossing farther north and thus keeps snow confined the far northern Ohio counties and the snow belt.

I wouldn’t be too disappointed, though. Our historical odds for snow on Christmas Day in the Valley is fairly low anyway. Odds this year will be even lower than average.

WHAT ABOUT AFTER CHRISTMAS?
In a word, mild. The latest climate modeling shows we can expect temperatures to remain above average through New Year’s Day. Remember, though – warmer than average doesn’t mean 70°. This is late December and our average temperature for late December runs in the 29° to 31° range.

Should the current outlook for warmer than average temperatures prove to be correct, it will be a drastic change from last year’s arctic cold temperatures during that week between Christmas and New Year’s. If you remember, last New Year’s Eve, temperatures dropped to -5°.

While temperatures may be mild on New Years and perhaps even a few days after, climate modeling indicates that colder temperatures will eventually arrive. Recent model runs of the CFS show January – as a whole – will be colder than average in the eastern US.

Of course, Christmas is 7 days out and all of this could change. Models are just models. They are not always right. I would never tell you that a forecast for next week is set in stone. But, with what I’m looking at today (Tuesday the 18th), I’d have to say that odds for a White Christmas here in the Valley are slim at best. None of the models show any signs of a system that would bring a potential for noteworthy snow.

Merry Christmas!