The NBC Boston Early Warning Weather team has issued an Early Warning Weather Alert through Wednesday morning at 8 AM. Snow is expected to develop from southwest to northeast across Southern New England Tuesday midday through afternoon, reaching Connecticut during the late morning, Central Massachusetts and Cape Cod around midday and Boston to the Merrimack Valley during the early afternoon. Though intensity will mostly be light to moderate, snow falling onto subfreezing road surfaces this evening likely will make for some slick spots – particularly away from any chemically pretreated interstates. Snow continues overnight Tuesday night, slowly drifiting northward overnight Tuesday night, tapering early Wednesday morning in most of Southern New England. Bursts of snow will continue in Northern New England on Wednesday, likely heaviest near Penobscot Bay in Maine. By the time all is said and done, about four inches falls in much of Southern New England with locally higher amounts in Southern Worcester County, near Cape Ann in Eastern Massachusetts, along the Berkshires and Green Mountains, and near Penobscot Bay in Maine. NECN and NBC Boston will continue to provide updates.
This week, New England's weather pattern changes in two notable ways: temperatures more typical of the season arrive and a series of energetic disturbances bring the likelihood of some periods of snow or snow showers.
The week begins with a quiet Monday for most, though already some changes are seen on the weather map, namely an energetic disturbance exiting the New Jersey coast Monday morning, traversing the Gulf Stream waters of the Western Atlantic and growing just large enough to deliver some flurries to the Outer Cape and the Islands - particularly Chatham to Nantucket - Monday evening. No appreciable accumulation is expected from this evening's flurries.
With active, fast jet stream winds in the skies over the Northeast, it won't take long for the next energetic disturbance to skirt the Northern Tier of the United States from Western Canada, arriving to New England later Tuesday afternoon. Though the jet stream winds aloft represent the storm-steering river of air high in the sky that brings disturbances nearby, those same jet stream winds also separate cold air to the north from warm to the south...and that temperature boundary becomes important in the days ahead. For instance, as the next energetic disturbance approaches in the skies above, nearly all of New England will be entrenched in cool air Tuesday, meaning snow showers will develop from south to north Tuesday afternoon through evening. The approaching disturbance will be sending a shot of milder air northward into Southern New England, and it's the clash of antecedent cool with incoming warmth that will aid in the development of snow bursts Tuesday evening and night from south to north, mixing with or changing to raindrops on Cape Cod, then ending from south to north in Southern New England after midnight Tuesday night into Wednesday morning as the clash of warm and cool air shifts to Central and Northern New England. Of course, while this means Wednesday warms up and dries out in Southern New England, snow showers will shift to Central and Northern New England through at least the first half of Wednesday, remaining positioned in the eroding cool air. For one and all, accumulations won't be exceptional, with a coating to an inch or two from south to north in Connecticut, Rhode Island and Massachusetts, and a couple of solid inches in Vermont, much of New Hampshire and Maine.
Once our midweek disturbance passes, a break in the action will take hold Thursday through most of the weekend, as New England transitions into chillier, though drier, air from Canada. An active weather pattern is likely to resume next week - Sunday night into Monday and perhaps again on Wednesday - as cold air begins to retreat and the storm-steering jet stream winds aloft near New England again, putting snow - and perhaps rain by midweek - back into the forecast.