Forecast discussion: After days of forecasting, a very strong low pressure system that brought blizzards to the Midwest and tornadoes to the Southeast is moving towards New England. Looking at the latest radar images, rain is falling over Boston at the moment, with sleet and freezing rain about an hour away. We have a number of advisories and warnings out for eastern Massachusetts. From the Mass Pike south to western Plymouth County, a Wind Advisory is in effect until 7 AM Thursday. For the eastern and southern coastlines, including the Cape and Islands, a High Wind Advisory is in effect until 11 AM Thursday. Finally, due to strong northeast winds, Boston is under a Coastal Flood Warning until 1 PM Thursday.
So, what does all this mean? As the low pressure systems moves closer to Southern New England, we will see increasing winds tonight into early Thursday morning. The capital city will see winds near 30 mph, while along the coast sustained winds could reach 35-40 mph. The snow will eventually turn into a mix of sleet and rain from south to north after midnight, as warmer air slowly moves into the region. By sunrise, temperatures will be warm enough for the precipitation to become all rain. Some rainfall could be heavy at times. Rain will taper off to showers by the afternoon. We may see some drizzle during the evening, before skies begin to clear after midnight Friday morning. I’m expecting a dusting to a half inch in the city before completely changing over to all rain.
A ridge of high pressure will give us sunny skies on Friday, but colder air behind the low will bring our high temperatures down into the upper 30’s. But, we will see more moisture as we enter Saturday. An area of low pressure will develop over eastern Texas on Thursday evening, and this low will slowly turn towards the northeast. We will see the precipitation shield by Saturday afternoon, and temperatures win the upper atmosphere will be cold enough to keep the precipitation all snow. At the moment, the low remains fair to our south and east. So, I would say we could see about 1-3 inches of snow by Sunday morning. However, I will continue to watch the models, because a change to the track could mean more snowfall.
Dry weather will return by Sunday night, with mostly sunny skies on New Year’s Eve. So, if you are heading out to First Night, it will be dry, but very cold. As we start 2013, a weak Alberta Clipper system could bring some snow showers by Tuesday afternoon. The low will quickly move offshore by the evening, and we return to sunny skies next Wednesday.
72 hour forecast:
Tonight: Light snow will turn to freezing rain/sleet by midnight, before turning to all rain by sunrise. Winds will be strong, blowing at 25-30 mph with gusts as high as 50 mph. We will see a low of 37. I’m expecting a coating to half-inch in the city before changing to all rain.
Thursday: Rain tapering off to showers by the afternoon. We will reach a high of 47 with winds diminishing from the north-northeast to 9-12 mph in the afternoon.
Thursday night: Partly cloudy skies after midnight with a low of 28. Winds will come from the northwest at 13-17 mph.
Friday: Mostly sunny with a high of 38.
Friday night: Partly cloudy with a low of 24.
Saturday: Partly to mostly sunny with light snow developing in the early afternoon and a high of 36.
Saturday night: Light snow ending around 5 AM Sunday and a low of 24.
Sunday: Partly to mostly sunny. Highs 31-34, lows 17-20.
Monday: Mostly sunny. Highs 30-33, lows 19-22.
New Year’s Day: Mostly cloudy with possible afternoon snow showers. Highs 30-33, lows 17-20.
Wednesday: Mostly sunny. Highs 27-30, lows 16-19.