The snow is gone now, but the cold air isn’t going anywhere today. Temperatures stay below freezing through around mid-morning, and temperatures top out in the low 40s this afternoon despite ample sunshine.
No big warm-ups for now
This post-Thanksgiving cold snap is the beginning of a cold start to December: below-average temperatures likely through at least the first 10 days of the month.
What is average in December anyway?
The climatological normal is thirty years’ worth of weather summed up and averaged out like a grade in a class. December’s usual ‘grades’ are 50s during the day and 30s at night.
There’s a catch, though. December is a very volatile student, and a peek at the individual grades over the years show that an single day’s range can be as much as 10-11 degrees above or below normal. In other words, a high of 44°F is just as expected as a high of 66°F, and a low in the 20s is about as common as one near 50°F.
A pattern like this one will keep things abnormally normal for the first 10 days of the month: highs stay in the 40s and 50s, lows hang generally in the 20s and 30s.
The cold weather pattern begins to shift in the direction of milder/warmer weather by mid-month. Instead of a deep ‘trough’ in the jet stream like we have now, the jet becomes a little more west-to-east oriented over the US. That doesn’t mean “warm” weather, but it should keep the coldest air up north for longer periods in between surges to the south.