An arctic cold front will plow eastward through New England on Wednesday and slip offshore Wednesday evening. Behind the front, bitterly cold air will pour into the region, sending temperatures to the single digits and teens Wednesday night through Thursday night.
The approach and passage of this frontal zone will be very much like that of a summertime cold front, with a thin but distinct line of heavy precipitation, gusty winds and a sharp temperature drop.
There are two main concerns:
- High Winds – As the front moves through the area, a strong low level jet will pass overhead (a corridor of much stronger winds higher in the sky). At the same time that happens, the temperature change with height will increase markedly, resulting in a very unstable deep “mixed layer” of air. This steep lapse rate environment will tap strong winds from aloft and drive them downward to the ground, bringing a short-lived but intense period of wind. Gusts over 50 mph are a good bet and it’s not out of the question that some spots gust to 60 or even 65 mph briefly. The period of concern is from about 4PM to 8PM.
- Intense Snow Squalls – The incoming arctic front will produce a fast-moving line of flurries, snow showers and embedded intense snow squalls. This activity will pass across Southern New England from west to east during the afternoon and early evening hours. It’s tough to say where the heaviest activity will be focused but it’s likely that a few locations in Eastern Massachusetts, including here on the Cape and on the Islands, see a burst of heavy snow resulting in near whiteout conditions…possible thunder and lightning….and a very quick inch or two of snow. Should this materialize as expected, travel conditions would be very difficult for a short-time.