Meteorological winter runs from December 1st through the end of February. On average these are our coldest days of the year. However, the majority of our snowfall tends to come from the middle of December through mid-March. This doesn’t mean it can’t snow in October or May, but the bulk of the white stuff falls in the previously mentioned period.

An interesting way to view winter snowfall is to review the daily averages. The chart below shows the daily average of snowfall increases through December and then levels off before declining in mid-March.

Although we still have 11 days left in the month of December I can already tell you it’s going into the record books milder and wetter than average with snowfall to be under average as well. Notice I don’t use the word “normal”, here in southern Maine there’s no such thing when it comes to weather.

This fall, many forecasters were predicting an above average snowfall year and average to below average temperatures for the winter. This may still happen with 2/3rds of meteorological winter still on the horizon. Full disclosure, I am concerned if the present storm track does remain through the winter, we are looking at a very wet and mild couple of months ahead. Snowfall will end up 15-30% under average in Portland, much lower than some of the fall forecasts. This doesn’t mean the ski areas don’t have a blockbuster snow season. Some of the best skiing can happen when the coast sees rain and the cold air is hung up in the mountains. These storms bring copious moisture and potentially a lot of snow for ski country and up north.

Forecasting the longer range is of course very tricky. (Those of you who love to comment on such matters can now head to the comments section.) As I have written before one of the many ways to think about what might happen over a winter is to look at how the atmosphere and oceans are similar today as they were in past years and then extrapolate to make a forecast for the upcoming winter. This winter will take place with weak El Nino conditions and some of the analog years that look similar to this one are 1905-06, 1914-15, 1939-40, 1941-42,1951-52, 1952-53, 1986-87 and 2002-2003. Snowfall in Portland and surrounding areas in several of those years was well below average, but also exceedingly high in others. This makes snowfall forecast very tricky.

There’s been a lot of moisture this month and if the track of two of these storms had been 100 miles in a different direction then we’d be on pace to one of the snowiest starts to winter on record. In Caribou, where it’s been just cold enough this is the case.

You might think, the if scenario is silly because we could say if it had been sunny and warm then the grass would be green, however there is some worthwhile thinking here. The pattern has been stormy as predicted, it’s been the cold that’s been lacking this month and will likely continue to be lack for the rest of the year. This means a low chance of any significant snow through New Year’s Eve. Of course, this can change, but that’s how I see it now.

This isn’t unusual, winter in southern Maine is particularly variable with wild swings in temperature and snowfall from week to week, month to month and year to year. If you want to go mow your lawn while you still can, why not do it?

Santa Gets Wet
Another storm will bring a windswept rain for Christmas Eve along with very mild air. This weekend is going to be typically chilly for the second half of December with sunshine and clouds mixed. At times it may be completely cloudy and along the coast of York County a bit of snow or rain could fall late Saturday night or Sunday, but just nuisance type precipitation.

The Christmas Eve storm is still 4-5 days away so the details can change in terms of amount of rain and wind and just how warm we get, but would take a Christmas miracle to see Santa sledding through Deering Oaks on a freshly fallen snow.

Tides are astronomically high next week, so there is the risk of some coastal flooding, but the storm won’t last long enough or bring northeasterly winds, both of which happen in the worst of New England storms.