8:29PM
Here comes a winter storm. A decent-sized one for a good portion of southeastern New England. Historic? Not even close. More like moderate to major. But impacts and snow amounts will vary depending on location, and the following is a breakdown of what to expect.
Why: Because it’s winter, and the clash of air masses in winter can often lead to winter storms. Just the basics. But seriously, it’s a low pressure system moving northeastward into the Upper Ohio Valley and interior Northeast then redeveloping off the Middle Atlantic Coast and taking the classic track just southeast of Cape Cod. The storm will have a decent amount of moisture and a pretty decent cold air mass to work with.
What is not a major factor: Wind. Only moderate and gusty winds, mainly along the coast. Tides / coastal flooding. Lack of strong wind and tides that are not astronomically high.
What are the main factors: Heavy snow, especially the first half of Wednesday. Mixing with sleet and rain and a change to rain over parts of far southeastern areas. Power outages which may occur due to wires coming down as a result of heavy snow on them or tree branches falling across them. This will be most likely in East Coastal Massachusetts down through southeastern Massachusetts where snow will be wetter than areas further inland and northwest of Boston.
Start time: 4AM to 6AM from west to east.
Heaviest precipitation times: 7AM to 1PM, as snow everywhere at first, then as sleet/rain over Cape Cod and the South Coast of MA and RI, with a sleet/snow mix moving northward toward Boston but probably falling just short of overtaking the city. Snowfall rates of 1 to 2 inches per hour, where it is snowing without any mixing, are likely during this time.
End time: Slow tapering of snow from west to east mid afternoon through evening, rain/sleet changing back to snow in far southeastern and south coastal areas before ending.
Accumulation (for the entire storm): 2-4 inches Cape Cod and Islands westward along the South Coast of MA and immediate coast of RI, some turning to slush during mix/rain. 4-8 inches over the remainder of southeastern MA and interior RI except the far north, wet snow with fairly high water content. 8-10 inches elsewhere except pockets of 10-12+ inches from I-495 north and west in areas north of Route 2, highest amounts in higher elevations, with average consistency snow (not too wet, not light and fluffy either). The vast majority of the accumulation will occur in the first 8 hours of the storm, making it a front-end loaded storm, in terms of snowfall.
After it’s over: Dry and cold as high pressure dominates Thursday through Saturday.
Next storm threat: Of course everybody knows we’ve been watching a threat with significant potential for the Sunday-Monday time frame. Latest indications are that this system may develop and track a little too far south to bring a major storm to southeastern New England, but there is still enough disagreement in medium range guidance to be very uncertain. Long way to go. My feeling at the moment: not a major storm.
Updated forecast for southeastern New England (southern NH, eastern MA, and RI)…
TONIGHT: Clouds thicken. Snow arrives west to east before dawn and starts to accumulate right away. Lows in the 20s. Wind light N to NE.
WEDNESDAY: Overcast. Snow, heavy at times all areas early morning, continuing through late morning interior southeastern MA and RI northward but with a sleet mix working north toward Boston and possibly reaching the immediate metro area for a time, and a change to rain over Cape Cod and the Islands as well as the South Coast of MA and RI. Precipitation becomes lighter in the afternoon, snow north and west, mix to the southeast eventually turning back to snow. Highs 30-35. Wind NE 5-15 MPH except 15-25 MPH over Cape Cod and the Islands.
WEDNESDAY NIGHT: Mostly cloudy with areas of light snow and snow showers winding down by about midnight then clearing. Lows around 20. Wind N to NW 10-20 MPH.
THURSDAY: Mostly sunny. Highs 25-3o. Wind NW 15-25 MPH.
FRIDAY: Mostly sunny. Low 10. High 30.
SATURDAY: Partly sunny. Low 15. High 30.
SUNDAY: Mostly cloudy. Chance of snow showers PM. Low 20. High 29.
MONDAY: Partly sunny. Chance of snow showers AM. Low 20. High 28.
TUESDAY: Mostly sunny. Low 11. High 25.