Strong low pressure will develop along the Eastern Seaboard today and tonight and lift quickly northward toward New England on Tuesday, spreading a shield of heavy precipitation northward along with it. The storm will deepen into a rather powerful low pressure center as it passes over Cape Cod Tuesday afternoon and evening and lifts into the Gulf of Maine Tuesday night.
Yesterday’s forecast post outlined the question marks with respect to the storm’s ulimate track and the impacts that track would have on the amount of snow expected to fall across the area. Recent model runs have continued to hone in on a track closer and closer to the Cape – with some products even taking the system over and west of the Cape.
As such, milder marine air is expected to overtake the area during the day on Tuesday, resulting in a snow to rain scenario across parts of Southeast Massachusetts and throughout the Cape and Islands. However, before that mild air arrives, several hours of heavy snow are likely to fall Tuesday morning, with a period of near whiteout conditions possible for a time near or shortly before midday – resulting in a rapid accumulation of 2 to 3 inches of snow on the Outer Cape and likely closer to 4 to 6 inches toward the Canal prior to precipitation mixing with sleet and rain.
Early Tuesday afternoon “warm” air will surge into the area causing heavy snow to abruptly transition to wind-driven heavy rain, with downpours and perhaps even a rumble of thunder possible Tuesday afternoon before dry air invades and precipitation cuts off Tuesday evening. Expect pockets of street flooding and lots of standing water on area roadways Tuesday afternoon. All-in-all, just ugly travel weather from mid-morning throughout the remainder of the day.
In addition to heavy snow and heavy rain, the upcoming storm center will deliver a period of strong east and northeast winds, beginning Tuesday morning and peaking during the early to mid afternoon hours. Wind gusts over 50 mph are likely across the entire Cape and some scattered gusts to 60 mph are a good bet in places. The combination of heavy wet snow and high winds will cause some localized power outages.
Lastly, as high tide approaches during early afternoon some areas of beach erosion and coastal flooding are likely…and the National Weather Service has issued a Coastal Flood Warning to highlight those concerns.