We’re just a few days away from concluding the first month of meteorological winter and there certainly hasn’t been much winter weather thus far. In the shorter-term, this is unlikely to change significantly. Bare ground is the rule over southern New England, but take heart skiers, there is snow up north.
Clouds are going to continue for the next several days and while there could be a little bit of drizzle or rain Thursday and Friday, it will mostly be dry with daytime highs in the 40s, and temperatures just above freezing at night. A more significant rain storm arrives on New Year’s Day and continues on and off into Sunday. Temperatures are going to be well above average, reaching the mid and upper 50s this weekend. The dearth of cold and snow so far is not what New Englanders are used to.
One of the parameters I look at this time of the year is the temperature anomaly map. This shows the difference between what is predicted and the average temperatures for a particular time of year. I watch this pretty closely because it lets me know whether or not temperatures are going to be warmer or cooler than average. One of the things I’ve noticed over the past couple of weeks is that cold air forecast to move into the Northeast is quickly displaced by a mild flow.
For a while there has been a prediction of some arctic air after New Year’s, but now this too is looking less cold, and not forecast to last more than a couple of days. While no meteorologist at this point in the season would be willing to put a fork in winter and say it’s done, if the trend continues, it does not bode well for winter weather enthusiasts in southern New England. The general forecast for this winter was for less snow and milder conditions than average, and that ultimately could prove to be a winner of an outlook.
The issue is that the jet stream continues to funnel mild Pacific air across the country and into the Northeast. Additionally a ridge of high pressure over the southeast continues to become reestablished, preventing Arctic air from penetrating this part of the country. Indeed, if you look at the loop below, you can see the above average temperatures in warmer colors briefly become replaced by colder than average temperatures around the 3rd of January — but quickly that cold air is displaced once again by milder-than-average conditions by the 6th.
Obviously, a forecast that is so far out can change, but the tendency is for less — not more — cold air in the extended outlook. When there is an outbreak of Arctic air, it doesn’t appear that it’s going to last very long.
Finally, part of the lack of cold is simply our changing climate. One hundred years ago, the average December temperature in Boston was around 32 degrees, now it’s 36 degrees. Even Blue Hill’s temperature has gone up by nearly the same amount. This change means less cold overall and indeed that is what we have seen again this year.