A nor'easter (!!!!) is slated to dump heavy rain and snow from Pennsylvania to Maine starting tomorrow morning, and some folks could see double-digit snow totals by the time it's over. For a pleasant change of pace, there's not much uncertainty in who will get how much of what and when.
Oh my God it's a nor'easter!?
A nor'easter is another name for a coastal low that brings strong, northeasterly winds to coastal areas of New England. Nor'easters are infamous for causing blizzards along the I-95 corridor, which is why the name strikes terror in the hearts of millions when they vaguely hear one is coming from their friend's nephew on Twitter.
Despite news networks itching to roll out their "Nor'easter Death Watch" graphics, nor'easters don't always bring snow to the big cities, which is (thankfully) the case this time.
Whew, okay. What's going on?
By tomorrow morning, the GFS model places an upper-level low in a deep trough in the jet stream along the East Coast, with jet streaks (area of faster winds) over Quebec and the southeastern U.S. The approaching trough and orientation of the jet streaks will create the enhanced lift needed to help form a strengthening coastal low off the Delmarva Peninsula by sunrise on Tuesday.
All of the models are in pleasingly rare agreement on the general location and track of the storm, so there shouldn't be any surprises with this one. (Famous last words.)
Who will get what?
The track a coastal low/nor'easter takes is a crucial determining factor in who sees rain and who sees snow. Too far off the coast and nobody sees anything; too close, and it's all inland. It looks like this storm will track close enough to the coast that the rain/snow line will be firmly impacted inland, providing all the big cities with a cold, wind-driven rain. Inland communities (think: Scranton, Albany, Utica, Rutland, Burlington) will see the heavy, accumulating snows with this one.
Most of the I-95 cities from Virginia to Maine will see one to three inches of rain tomorrow and Wednesday—less/earlier south and more/later north. As you head deeper into lobstah territory, cities like Boston and Portland could pick up a quick dusting of snow as temperatures cool and rain changes over towards the end of the event.
The current thinking from the National Weather Service is that the storm will produce a wide swath of double-digit totals from northeastern Pennsylvania through deep interior regions into Maine. It's not a far cry to think that someone somewhere could see two feet of snow by daybreak on Thursday if they get stuck under a heavier band.
The worst conditions will occur in Maine, as much of the state will experience a period of heavy, wet snow before the precipitation changes over to freezing rain and sleet. A modest coating of snow is fine, but when it snows and then you get freezing rain on top of that, it compacts/freezes the snow and adds a phenomenal amount of weight to any exposed surfaces.
The winter storm watch in effect for much of central and northern Maine mentions the potential for one-quarter to one-half of an inch of ice accretion on top of six to ten inches of snow.
How bad will this be?
On a scale from "meh" to "call the Pope," this storm should be a solid "enjoy your snow day" inland and just a miserable, raw Tuesday for folks in the cities. The snow will fall in an area of the country where they've A) already seen snow this year, and B) are more than capable of handling it. There will be enough snow to cause many districts to call off school for a day and possibly cause you to miss a day of work, but it won't otherwise be some hugely disruptive event...unless you're in Maine.
The potential for significant ice accretion on top of a healthy coating of snow, mixed with the likelihood of gusty winds, could create widespread tree damage and power outages across a large chunk of interior Maine. If this storm is going to be remembered one day, this is where it'll happen. If you live in areas of Maine where wintry precipitation is expected, make sure you're prepared for and have enough supplies to last you a few days in the event of an extended power outage.
Elsewhere, the biggest problem with the storm could be power outages as a result of gusty winds. This should be a problem more confined to the coast than the snowy inland areas, but heavy snow and the added force of gusty winds could cause some issues on weaker trees and lines. On the coast, as rain moistens and loosens the soil, strong winds will have an easier time causing damage that could result in power outages. Gusts could reach 45-50 MPH from coastal Massachusetts to Maine on Tuesday night.
Flooding is also a concern, and as a result, most counties from the NYC metro area up through Connecticut, Rhode Island, and eastern Massachusetts are under flood watches for the potential for heavy rain to outpace the capability of storm sewers to handle it. If you live in an urban area, watch out for street flooding in low-lying trouble spots.
It's a classic nor'easter for your mid-December workweek. We've got four more months to go—tempting as it is with the flashy graphics and breathless live reports, let's not spend all of our panic capital on this one.
[Images: AP, WeatherBELL, NWS]