Forecast discussion: After an evening of moderate to heavy snow in eastern Massachusetts, but light to moderate snow in the southern part of the state, we saw a range of only an inch (Acton) to just over 18 inches (Norwell). Meanwhile, the Cape and Islands had to deal with ocean effect snow showers for most of the day. Now, an Arctic blast will be coming down into New England over the next few days, making the days quite chilly and overnight lows somewhat dangerous.
Like the cold air outbreak a few weeks ago, temperatures during the overnight will be only in the single digits. Winds will be light, but any wind will make our skin feel like it is about 10 below zero this evening. Despite sunshine for Thursday, wind chills will still be around 10 below zero. So, why isn’t it warmer? Well, the fresh snowpack has a lot to do with it. The sun’s rays are usually absorbed by the ground during the daytime before being released during the evening. However, the fresh snowpack basically “bounces” the radiation back into the sky. So, the air temperatures cannot increase. In weather terms, we call this an albedo.
Also, because we will have high, thin clouds at night, the radiation escapes. However, Friday night will be an exception. Thanks to increasing cloud cover, any radiation during the time will not escape, and remain in our atmosphere. The cloud cover is almost like a blanket you put on top of a bed. It will keep the heat in, allowing temperatures to only fall into the lower teens.
Also, winds will turn from the northwest to the southwest, which is a warmer wind direction, by Friday night. On Saturday, temperatures will actually reach freezing, despite cloudy skies. But, a low pressure system moving through the Great Lakes will help bring another round of light snow, starting by the early afternoon. It will end by early Sunday morning, with light accumulations expected.
A quick moving Alberta Clipper will bring the chance of more snow showers Sunday night into early Monday morning. Once again, this will bring light snowfall. As we head through the middle of next week, the Arctic blast will return, briefly, by Monday night, as temperatures fall into the single digits. But, warmer air from the south will help warm temperatures into the lower to middle 20’s by next Wednesday.
72 hour forecast:
Tonight: Partly cloudy and bitterly cold with a low of 5. Wind chills will be near 10 below zero.
Thursday: Mostly sunny with a high of 17. Winds will come from the west-northwest at 9-12 mph. Wind chill values will be anywhere from 8 to 13 below zero.
Thursday night: Partly cloudy with a low of 5. Winds will come from the west-northwest at 9-12 mph. Wind chill values will be around 5 to 10 below zero.
Friday: Mostly sunny skies with a high of 17. Wind chill values will be near 10 below zero.
Friday night: Increasing clouds during the overnight and warmer with a low of 13.
Saturday: Mostly cloudy with light snow by the early afternoon and a high of 35.
Saturday night: Light snow ends after 2 a.m. with a low of 16.
Sunday: Partly to mostly sunny, with possible snow showers in the evening. Highs 22-25, lows 16-19.
Monday: Snow showers end by 7 a.m. but remaining mostly cloudy. Highs 31-34, lows 5-8.
Tuesday: Mostly sunny. Highs 17-20, lows 8-11.
Wednesday: Mostly sunny. Highs 23-26, lows 15-18.