Winter will mark its arrival with a bang on Monday and Tuesday mornings. The warm, humid days of December may very well seem like a distant memory as an arctic airmass seeps into the Northeast United States, first on Sunday and again Monday with the passage of an arctic front. Very cold mid and upper level atmospheric temperatures will dive southward into the region from Canada, as high pressure builds in overhead.
With the passage of an arctic cold front on Monday will come very cold air, blustery winds, and the potential for a few snow showers or squalls. While these snow showers aren’t expected to bring any notable accumulation, they may be just enough to reduce visibility at times on Monday.
For comparisons sake, the mid level atmospheric temperatures moving overhead on Monday and Tuesday will be dramatically colder than what we experienced just two weeks ago. 850mb temperatures (so about 5000 feet above the ground) will fall to nearly -20 C. This is a full 40 C colder than they were two weeks ago, when they exceed +18 C in many areas!
Behind the arctic cold front on Monday, light winds and clear skies will bring ideal radiational cooling conditions for Monday Night into Tuesday morning. Forecast models, accordingly, indicate the potential for the coldest temperatures of the young season. Temperatures look likely to fall into the single digits throughout the interior, and the low to middle teens even in the city and near the coastal plain.
Highs will only reach into the upper 20’s and lower 30’s — so be sure to bring your winter coat and layer up on both Monday and Tuesday. Slightly moderating temperatures are expected by the middle and latter part of the week.