Forecast discussion: After starting the morning with a Winter Storm Watch, the overnight computer models projected more snow for Boston and the rest of eastern Massachusetts. The National Weather Service than upgraded to a Winter Storm Warning. The warning will continue for most of eastern Massachusetts until 7 AM Sunday morning. A Winter Weather Advisory continues for most of Hyannis and the rest of Cape Cod. Also, a Wind Advisory will be in effect until 8 PM Sunday night.
Right now, snow is coming down at almost an inch an hour outside my weather office in Pawtucket, RI. We will continue to see moderate snow for the next three to four hours in the capital city. By then, the low’s center will move into the Gulf of Maine, and the heavier precipitation will lighten. We will taper to flurries around midnight. We will see some scattered snow showers and flurries before sunrise. I am expecting between 6-9 inches in the city. The coastline will see about 2-4 inches as they change over to snow. The rest of the eastern part of the state should see 4-6 inches tomorrow morning.
Once the system moves out, we will see a couple days of high pressure ridging over the region. But, it will remain windy, as the pressure gradient between the departing low and the incoming ridge remains tight. Also, polar air will be racing down from Canada, and it will be here after the last day of 2012.
We will be seeing a series of Alberta Clippers pass over Southern New England as we begin 2013. The snow showers will be brief, with no additional accumulations. Also, much colder air will come down via the jet stream by Tuesday night. Overnight lows will fall rapidly, staying just above single digits Thursday evening. Daytime temperatures will stay below freezing.
72 hour forecast:
Tonight: Moderate snow until midnight and windy, with snow tapering to flurries. All precipitation ends by 5 AM. We will see a low of 27.
Sunday: Mostly sunny and windy with a high of 32. Winds will come from the northwest at 17-22 mph.
Sunday night: Partly cloudy and very cold with a low of 17. Winds will come from the northwest at 15-20 mph.
Monday: Mostly sunny with a high near 31.
Monday night: Partly to mostly cloudy with a low of 23.
New Year’s Day: Partly sunny with passing flurries and a high of 32.
Tuesday night: Mostly cloudy with a low of 13.
Wednesday: Cloudy with a passing snow shower in the afternoon. Highs 26-29, lows 12-15.
Thursday: Mostly sunny. Highs 24-27, lows 9-12.
Friday: Mostly sunny. Highs 23-26, lows 11-14.
Saturday: Mostly cloudy. Highs 30-33, lows 17-20.