DAYS 1-5 (FEBRUARY 1-5)
Welcome to February! We start the second month of 2021 off with a winter storm. The timing of the event has been slipping a little more to the earlier side with time, and we’ve already had some snow from the evolving system falling in parts of southern New England, even some minor accumulation, but it will continue to fight a dry air mass over the region and take several hours to really get going and make a solid push northward. At the same time, some ocean-effect snow showers may be drifting in from the east. Looking at the temperature profile this morning, with 30s over Cape Cod and 10s over interior southern New England, we’re probably already looking at the formation of a coastal front, probably a little further west than we typically see it. This will allow snow that falls over interior MA and northeastern CT and maybe northwestern RI, well as interior southern NH to be a little fluffier and pile up better, whereas snow that falls east of that boundary will be a wetter variety. We’ll have to monitor for where the exact set-up of this boundary is, but my best guess is the I-495 belt for the longest period of time. But, the east winds are occurring really over Cape Cod as of 7 a.m., with winds from the northeast or north elsewhere, so the boundary itself is probably setting up to the southeast of Boston initially before it migrates westward with time. I’m still expecting the strongest band of precipitation to push from south to north through the region from early afternoon to early evening in southern areas (CT, RI, southern MA) and later afternoon into late evening in areas to the north (central to northern MA into southern NH). I am not making any big changes to the snow amounts I posted yesterday, other than adding an inch or two and allowing for a little more fluff factor over inland areas, and of course the rain/snow line will be monitored as it certainly looks like it will be involved over Cape Cod and into parts of the MA South Shore, and then we’ll see how far it can get beyond that. It may never quite have enough push to get into or through the Boston area until after the heaviest precipitation has shut down anyway, so here is an updated run-down of my expected snowfall accumulation after we’re done with that main band of precipitation late tonight…
Up to 2 inches outer Cape Cod, 2-4 inches remainder of Cape Cod and immediate South Coast to the eastern side of Buzzards Bay and South Shore of MA up to Plymouth, as well as the upper part of Cape Ann MA, 4-8 inches immediate NH Seacoast to immediate North Shore of MA, Logan Airport, interior southeastern MA to Narragansett Bay, 8-12 inches most of RI and northeastern CT as well as south central MA northeastward through Metro Boston and up to northeastern MA and southeastern NH away from the immediate coast, and 12-16 inches north central MA through southwestern NH, highest amounts in the higher elevations. It’s important to keep in mind the sharp snowfall gradient expected in eastern areas and that on-the-fly adjustments may be needed as very subtle changes in the overall storm behavior leads to significant changes in snowfall amounts in these sharp gradient areas.
As far as coastal impact from the storm, we’ll have to keep an eye on the today’s afternoon high tide for some minor flooding in southern coastal MA and RI but not expecting a big issue, then minor to pockets of moderate coastal flooding with both high tide cycles Tuesday on east-facing and north-facing shores especially. And to summarize the power outage risk, it will be there, but I don’t expect widespread problems, since the areas with the greatest snow accumulation now look like they may have a little bit of a drier consistency to the snow at least to start out. However do expect enough sticky snow to fall in at least parts of the region for potential power disruptions. The strongest wind gusts being along the coast and especially Cape Cod may also contribute to some power outages there as well.
Looking ahead, we stay unsettled Tuesday with scattered rain/snow showers in a slightly milder atmosphere, before colder air sneaks back in on Wednesday and the energy from the original low pressure area comes across with the potential for some morning snow or snow showers, though that does not look like significant additional snowfall – more nuisance variety. The rest of Wednesday should turn dry, breezy, and chilly behind the departing complex storm system before high pressure moves in for a nice winter day on Thursday, allowing any remaining storm cleanup to finish up. By Friday, it’s back to unsettled weather, but this time its from low pressure passing northwest of New England. Its warm front may cause brief rain/mix/snow early before we warm up and see a risk of rain showers ahead of an approaching cold front.
TODAY: Overcast. Patchy light snow anywhere and a few snow showers off the ocean possible in eastern MA this morning. Steady snow arriving south to north from late morning through early afternoon across the entire area, may mix with rain quickly over Cape Cod. Highs ranging from near 20 in north central MA an southwestern NH to near 35 Cape Cod. Wind N to NE 5-15 MPH interior areas, NE to E increasing to 10-20 MPH coastal areas with higher gusts especially southeastern MA.
TONIGHT: Overcast. Moderate to heavy snow except mix coast and rain Cape Cod evening, tapering off to a few rain/snow showers south to north overnight. Temperatures rise to 27-34 except 35-42 coastal areas, warmest Cape Cod. Wind E to NE 10-20 MPH with gusts as high as 30 MPH inland, 15-25 MPH with gusts as high as 40 MPH coastal areas, except 25-35 MPH with gusts 50-60 MPH Cape Cod.
TUESDAY: Cloudy. Occasional rain & snow showers. Highs 35-42 morning, falling slightly in the afternoon. Wind NE to N 10-20 MPH with gusts to 30 MPH inland and 15-25 MPH with gusts to 40 MPH coastal areas except 45-55 MPH Cape Cod, especially in the morning and midday.
TUESDAY NIGHT: Mostly cloudy. Additional mix/snow showers evening. Lows 25-32. Wind N to NW 10-20 MPH, higher gusts.
WEDNESDAY: Mostly cloudy with a chance of light snow or snow showers morning. Partly sunny afternoon. Highs 33-40. Wind N to NW 10-20 MPH, higher gusts.
WEDNESDAY NIGHT: Partly cloudy. Lows 22-29. Wind NW 5-15 MPH, higher gusts.
THURSDAY: Mostly sunny. Highs 36-43. Wind NW 5-15 MPH becoming variable.
THURSDAY NIGHT: Increasing clouds. Lows 25-32.Wind variable to SE up to 10 MPH.
FRIDAY: Mostly cloudy. A touch of rain/mix/snow possible in the morning. Chance of rain showers in the afternoon. Highs 38-45. Wind SE up to 10 MPH morning, SW 10-20 MPH afternoon.
DAYS 6-10 (FEBRUARY 6-10)
Colder air moves back into the region during the February 6-7 weekend but not as cold as the air mass we are just getting rid of now, so while there is the chance of unsettled weather from 1 or 2 low pressure areas impacting the region through early February 8, the precipitation type and timing is indeterminate at this point and this forecast will be brought into focus over the next few days. Expecting fair and colder weather to return later February 8 through February 9 with a moderation in temperature by the end of the period when we’ll have to watch for a bit of unsettled weather.
DAYS 11-15 (FEBRUARY 11-15)
Temperatures look a little more moderate heading into mid month. Next unsettled weather threat comes during the middle of this period, but this remains a low confidence forecast with only vague ideas possible for now. More evaluation of the mid month pattern can be done after we get by the current storm.