The wild card now is whether we see some snowflakes. “We cannot rule this out,” Junker said, because there’s the chance a storm system could lift through the region Christmas Day, riding along an Arctic front pushing toward the East Coast. Precipitation is likely to begin as rain Christmas Eve but, as cold air oozes eastward, some areas could see a period of snow early Christmas Day.

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“The big question mark is how deep in the cold air we’ll be on Christmas and whether the precipitation hangs around long enough to allow a period of light snow towards the end of the precipitation,” Junker said.

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Of our two long-range modeling systems, the American and the European, the American model presents a colder forecast with a little more snow potential.

The American model

The American model brings an Arctic front through the region on Christmas Eve, with temperatures falling into the 30s on the night leading into Christmas. Meanwhile, a weak storm system forms along the front to Washington’s southeast and throws back enough moisture into the cold air for some wet snow in the predawn hours of Christmas Day.

Among the American model’s 21 ensemble members, simulations of its main model with input data tweaked, eight suggest some accumulating snow around Washington.

As usual, if you live well north and west of the District, you stand a better chance of seeing snow than locations to the south and east, where cold air will be slower to arrive.

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The European model

The European model predicts a warm, rainy Christmas Eve as mild air streams north ahead of the Arctic front. By Christmas Day, the front presses east of Washington and temperatures start to fall, but the rain occurring along the front ceases Christmas morning before it turns cold enough for any wintry precipitation. The model predicts a high in the mid-40s around midnight, with temperatures steady or falling thereafter.

A few members (4 of 51) of the European model ensemble do bring in enough cold air for accumulating snow on Christmas Day — so it’s not off the table.

The model has, however, abandoned its earlier idea that the front would take until Christmas night to pass, allowing temperatures to spike to near 70 during the day.

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Closing thoughts

In addition to the primary scenarios presented by the American and European models discussed above, it could also end up dry Christmas Day if the cold front pushes too far to the southeast, taking the storm system out to sea. Finally, there’s the outside possibility the front slows down, and it turns rainy and mild Christmas Day like the European model was predicting previously.

Whereas Washington’s odds of having at least an inch of snow on the ground Christmas Day are historically just about 10 percent, having this Arctic front come through has increased them to around 15 percent, Junker said.