Forecast discussion: A very weak area of high pressure over eastern Canada kept our weather dry in Boston on Thursday. However, a low pressure system well offshore of North Carolina will bring the threat of some isolated showers and drizzle this evening. This system has helped keep dense fog over eastern Massachusetts, as well as the Cape and Islands, all day. A Dense Fog Advisory will be in effect until 4 a.m. Friday morning.
Once the system moves further into the Atlantic, the high will gain more of an influence on the weather Friday. We will see mostly sunny skies and temperatures reaching the middle 40’s. But, the dry weather will end, as a low pressure system over Michigan will bring some snow showers over us early Saturday morning. Eventually, the precipitation changes to rain showers, so I am not expecting any snowfall on the ground. Some moisture on the backside of the low will produce a few snow showers during the daytime on Sunday.
We will see more clouds than sun for the holiday on Monday, while I continue to monitor the models for a possible storm for Tuesday night into Wednesday. Right now, all computer models develop a surface area of low pressure just offshore of New Jersey on Tuesday morning. The low will move offshore, and become stationary. Some upper level dynamics will come from the west, and help strengthen and intensify the low. Right now, it appears most of the precipitation stays offshore. The models vary on how strong the low gets, but they all agree the low stays far enough from eastern Massachusetts to see any significant snow totals. My overall confidence remains low, as this is still five days away, and the models could change this scenario.
The models do agree on seeing another strong blast of cold air returning to New England after Tuesday afternoon. High temperatures will struggle to reach the lower to middle 20’s for daytime highs by Wednesday. However, computer guidance is suggesting even lower temperatures. This is due to the fact the models are thinking significant snowfall will be on the ground from this possible system. Fresh snowpack reflects the sun’s energy back into the atmosphere, making temperatures colder. For now, I will keep high’s in the lower 20’s with overnight lows remaining in the lower teens.
72 hour forecast:
Tonight: Cloudy with drizzle and isolated showers until 3 a.m. with patchy fog. Skies will begin to clear by 5 a.m. We will see a low of 33.
Friday: Mostly sunny with a high of 45. Winds will come from the south-southwest at 8-11 mph.
Friday night: Mostly cloudy with a low of 34. Winds will come from the south-southwest at 5-8 mph.
Saturday: Scattered snow showers in the early morning changing to rain showers by the late morning with a high of 43.
Saturday night: Showers ending by 7 p.m. but remaining mostly cloudy. It will be getting colder with a low of 24.
Sunday: Mostly cloudy and colder with possible snow showers in the late morning and late afternoon with a high of 35.
Sunday night: Light snow ends by midnight with a low of 24.
Martin Luther King Jr. Day: Partly sunny. Highs 36-39, lows 18-21.
Tuesday: Increasing clouds during the mid-afternoon, with light snow possible in the evening. Highs 28-31, lows 13-16.
Wednesday: Cloudy with possible light to moderate snow. Highs 21-24, lows 11-14.
Thursday: Partly to mostly sunny. Highs 20-23, lows 10-13.