New England is gearing up for another storm that will deliver one to two feet of snow for most of the Northern half of New England, with near blizzard conditions possible through interior Central and Eastern Maine Saturday evening. And here's something for you - just received word that Guilford, New Hampshire has canceled the Winter Carnival for this weekend...because there's TOO MUCH SNOW. Now there's one heck of a winter for you.
Our morning began downright frigid in many areas, with North Country valleys dropping to colder than 30 below zero! It was a rapid rebound with sunshine assisting in the comeback of temperatures, but the dome of cold, arctic air in place will ensure temperatures don't exceed the teens in Northern New England and twenties in the southern half of the six-state region. Of course, arctic air is also dry air, and this has kept sunshine a player in the forecast for most of Friday, though clouds will increase later Friday afternoon in advance of the next storm, whose precipitation will spread across New England Friday evening and night, continuing into and for some communities right through Saturday.
As of this Friday morning writing, the current state of the upcoming storm is rather unimpressive over the Central Great Lakes with a relatively thin band of snow moving east across Detroit and Cleveland. Earlier this morning, however, rain blossomed across the Tennessee Valley - evidence of Gulf of Mexico moisture being drawn toward the storm center and providing ample moisture for a rapidly expanding swath of precipitation. This is the first step toward breeding a stronger storm center. Of course, another step will be to develop a strong difference between northern cold air and southern warmth - conditions that a storm thrives off of and can strengthen handily in. Though right now that difference in temperature, or "baroclinicity," is not present here in the Northeastern United States, the counter-clockwise flow around the approaching area of low pressure will usher warmth northward, establishing this boundary across New England at the very same time the storm center passes overhead Friday night through Saturday, drawing Atlantic moisture into the region as it winds east, as well. This means the conditions necessary for storm development and strengthening will be present at the moment the storm circulation comes through, implying the storm should intensify overhead, and seems likely to reach its peak strength while along the coastline of Maine Saturday afternoon and evening, raising the potential for blizzard conditions through the interior of the Pine Tree State at that point.
But let's not get ahead of ourselves - precipitation is expected to expand east across New England from west to east this evening, starting as snow in all spots and breaking out around 7 PM in Western New England and by midnight in Eastern MA and Eastern NH, and may begin a bit later in Maine. With the air so cold, snow is definitely the most likely precipitation type at the onset, though a strengthening southeast wind will mean a change to rain fairly quickly on the Islands of Massachusetts and the Outer Cape, after between a coating and an inch of accumulation. Central and Western parts of Cape Cod may pick up an inch or two (or pehaps three near Sandwich) before an overnight change to rain with the southeast wind driving the rain/snow line inland and northward off the ocean. The farther north and west one is, the more snow that will fall as the deep arctic incursion across New England has not only brought cold temperatures, but also dry air - and dry air cools when saturated, meaning even as the temperature moderates a bit by day's end and evening, the addition of moisture will contribute to cooling the air and keeping snow as the dominant precipitation type. Snow will fall heavily in the predawn hours of Saturday, with the rain/snow line perhaps backing through Boston around 7 AM or so (rough estimate), the continuing northwest, reaching the Massachusetts/New Hampshire border by late morning or midday. Of course, by that point most of the precipitation will have already fallen. It goes to figure that amounts in the accumulation map below correspond to increasing amounts the farther north and west one is - but especially with northward extent. Though the snow will be somewhat wet and sloppy in Western New England, it will be rather fluffy in Northern New England, boosting accumulations. As the storm center passes from Southern Vermont Saturday morning to just off the mid-Maine coast Saturday evening, warmth will be drawn southward enough to change snow to rain in Central and Southern New England, but this occurs as drier air comes in under the belly of the storm, tapering precipitation. In Maine and Northern New Hampshire, however, snow will continue Saturday through the afternoon and evening, with a coastal front separating ocean air and cold land air resulting in a band of extremely heavy snow just inland from the Maine coast, where snow may fall at up to 4" per hour at times Saturday afternoon!!! It's in these areas that I'm expecting one to two feet of accumulation. Even in Southern areas where things dry out a bit Saturday afternoon, a renewed band of snow is possible in Eastern MA - especially Northeastern MA - through Eastern New Hampshire Saturday night as wraparound snow backs around the west side of the deep storm center, which slows off the Maine coast Saturday evening. It's during this same time period of storm strengthening that winds will turn to blow from the northeast and increase across interior Maine, possibly creating blizzard conditions for Saturday late afternoon through evening - though it's marginal, that certainly is a possibility.
Some snow showers will probably still linger Sunday morning in Maine and New Hampshire, and clouds may still wrap around the back of our storm all the way into Eastern Massachusetts Sunday morning, but should diminish as the day wears on and the storm fizzles. A warm front will move across New England Monday with periods of clouds but milder temperatures will nudge toward New England, arriving into Southwestern New England first. Tuesday carries a cold front to New England with moisture streaming north out of the Gulf of Mexico, meaning some light snow and rain is possible, but a transition to mostly rain seems likely as warmer air continues to move in ahead of the storm center, strengthening to our west late Tuesday into Wednesday.
It still seems likely that the active stretch will continue through at least the first half of March as a jet stream trough to our west continues to favor strengthening disturbances that will have access to Canadian cold dipping across the Great Lakes to their north, and deep Gulf of Mexico moisture to their south as they round the base of the U-shaped trough over the Ohio and Tennessee Valleys and move toward the Atlantic coastline.
Enjoy the weekend!
Matt
