9:50AM
PART 1 – THIS STORM
Deepening low pressure tracks from the Mid Atlantic northeastward and will pass over Cape Cod MA tonight, and bomb-out (rapidly intensify) as it moves through the Gulf of Maine early Friday then away from the region. For southeastern New England, expect the following…
Precipitation/timing: Snow already developed early to mid morning across the region. Watch for a rain/snow line to cross Cape Cod then hang around the MA East Coast through midday. Heaviest bands of snow set up just northwest and west of this line. Rain/snow line progress inland during the afternoon. This line may delay for a while due to some cold/dry air aloft, before the warmer air finally overtakes it. Because of this I will add a little bit to the snow totals just inland. Dry-slot with less precipitation works northward into southeastern and eastern MA by early evening, but there may be a few lines of heavier rain showers and even thunderstorms in this region. Wrap-around moisture as the low pulls away moves back eastward as snow to the west and rain/mix back to snow eastward, though may be only spotty and light the further south and east you go in MA and RI. All of this should exit the region from southwest to northeast Friday morning.
Snow accumulation: Coating to 1 inch Cape Cod and Islands, 1-3 inches near Cape Cod Canal and Buzzards Bay areas up through eastern and central Plymouth County MA, 3-6 inches southeastern RI up along and just east of I-95 to the NH Seacoast, 6-10 inches west of this region with the higher amounts near and outside of I-495 from the Mass Pike region northward, 10-15 inches in higher elevations of north central MA into southwestern NH. An additional small accumulation may occur when a change back to snow takes place in the early hours of Friday.
Wind: Gusts 40-50 MPH likely along the coast from the E as the storm approaches, becoming variable as the low crosses Cape Cod, and backing to N as the low begins to pull away toward the Gulf of Maine early Friday morning. Inland winds will be less strong, but will likely get stronger from the NE to NW during the morning Friday, gusting 35-45 MPH. Some wind damage may occur especially where wet snow weighs down trees and power lines. There may be little or no snow on trees and lines where winds are strongest, however, which would reduce the risk of outages somewhat.
Coastal flooding: Astronomically low at this time. Minor flooding and moderate splash-over likely especially around the time of high tide Thursday night (9PM-midnight). Splash-over is likely on north-facing shores during Friday morning’s high tide, but should be relatively minor.
PART 2 – A LOOK BEYOND
Low pressure pulls away later Friday leaving it drier and windy, but winds die down late. Another low pressure area tracks across or just south of the region early Saturday with a threat of additional snow – best chance of accumulating snow from Boston area south. Doesn’t look like a major storm, but close enough and potentially rapidly-intensifying low so much keep a close eye on it. Cold/dry Sunday-Monday. Next low pressure area Tuesday with snow/mix/rain possible.
Updated forecast for southeastern New England…
TODAY: Overcast. Snow grows steadier and heavier. Rain/snow line crosses Cape Cod and Islands and onto eastern MA and eventually NH coast, working inland during the afternoon, including east to west across RI. Sleet and some freezing rain along the changeover zone, greater threat for a period of freezing rain inland where it stays colder at the surface longer. See snow accumulations above. Highs by late day 32-44 from northwest to southeast across the region. Wind E to NE 15-35 MPH with higher gusts, especially coastal areas, becoming variable over Cape Cod / Islands late day.
TONIGHT: Cloudy with mix/snow tapering off then another period of snow inland areas later, rain showers eventually changing to snow showers further east and south. Lows 25-30. Wind NE to N 15-35 MPH with higher gusts.
FRIDAY: Mostly cloudy to partly sunny. Snow or snow showers likely through mid morning eastern MA and southern NH. Snow may be briefly moderate to heavy with some accumulation and slippery roads especially north and northwest of Boston. Highs in the 30s. Wind NW 15-35 MPH with higher gusts, diminishing late in the day.
SATURDAY: Mostly cloudy with snow or snow showers in the morning, especially Boston area southward. Lows around 20. Highs around 30.
SUNDAY: Mostly sunny. Lows around 10. Highs around 25.
MONDAY – PRESIDENTS DAY: Mostly sunny. Lows around 10. Highs around 30.
TUESDAY: Mostly cloudy. Snow to rain. Lows around 25. Highs around 40.