If you're unlucky enough to live in the snowiest region of the country this year, chances are you don't need any introduction to what's going to happen this weekend. Up to two feet of heavy, wind-driven snow will blast coastal New England on Sunday, making travel impossible and possibly producing some damage along the way.
A very strong jet stream will allow an approaching low pressure system from southern Canada to explode into a nor'easter as it moves off the coast near New York City on Saturday night. The optimal placement of the jet stream will foster a process known as "bombogenesis," or more commonly known as a "bomb," which occurs when a low pressure system rapidly deepens by 12 millibars in 12 hours, or 24 millibars in 24 hours.
This morning's run of the GFS model shows the low strengthening from around 998 millibars on Saturday night down to 964 millibars just one day later—an incredible 34-millibar drop in such a short period of time will produce a fast but ferocious blizzard with winds approaching hurricane force along parts of Cape Cod, and wind gusts of 50+ MPH along populated areas from Plymouth, Massachusetts, up the coast to the Canadian Border.
Who Will See Snow?
The system is almost indistinguishable on satellite imagery this afternoon; above is a water vapor image that shows moisture around 10,000 feet above the surface, with the system in question circled in red. The developing system is already producing snow across parts of Ontario and Michigan—winter storm warnings (and even a blizzard warning in the U.P. around Marquette) are in effect for snowfall totals of around six inches, in addition to near-blizzard conditions and extremely dangerous wind chills that exceed -20°F at times.
The system will grow more organized as it makes its way towards the Atlantic, dropping relatively negligible amounts of snow along the way. A general coating of snow (one to three inches) is likely across the entire Northeast, stretching possibly as far south as northern Virginia and central West Virginia. Once the nor'easter begins to develop, very heavy snow will fall across coastal New England from Massachusetts through Maine.
Again, the two phases of this storm will produce a widespread snowfall, but the heaviest, most focused precipitation will fall from Massachusetts through Maine and into the Canadian Maritimes. The latest forecast from the various National Weather Service offices across the region show a widespread coating of snow—generally one to three inches—with much higher totals to the east near the coast. Forecasters expect existing snowfall to be enhanced by lake effect coming off of Lake Ontario, which could push snowfall totals close to double-digits on the body's southern shore from Rochester to Fulton.
Snowfall totals will grow larger the closer you get to the Maine/Canadian border, with parts of eastern Maine seeing the potential of two or more feet of snow by the time the storm winds down. Measuring the snow will be hard thanks to incredibly strong winds and the inevitable drifts, so exact snow depth will fluctuate wildly depending on terrain, structures, and vegetation.
Boston, that world-class polar bear sanctuary on the harbor, isn't expecting the brunt of this storm for once! Hallelujah. It will still snow quite heavily in the city, and they're under a blizzard warning in anticipation of heavy snow and stiff winds creating whiteout conditions for a period of time on Wednesday. The city could see around ten inches of snow—more if the storm moves closer inland, less if the storm moves farther off the coast.
This is Boston's eighth snowiest season* on record, with a total of 79.5 inches measured so far this season at Logan Airport. Assuming the city sees 10 inches of snow in this storm, it would push the season to the third snowiest ever recorded in Boston. 1995-1996 was the snowiest season on record in Beantown, with 107.6 inches of snow on the books.
*I purposely use "season" instead of "winter" here. Since snow isn't confined to December through February, I'm using the "water year" (October 1 through September 30) to fully account for any snow that falls outside of that three-month period.
New York City is not included in the above graphic, but one to three inches of snow is possible across the metro area overnight on Saturday into Sunday. If it does indeed snow (we know how that goes), it'll be enough to make Central Park look pretty, but won't cause too many more issues. However, a light coating of snow will make sidewalks and roadways slippery (especially heavily-traveled and untreated surfaces), so you'll want to take care when you're moving around on Saturday night and Sunday morning.
This storm promises to be a full-fledged blizzard; a blizzard is defined as white-out conditions (visibility of one-quarter of a mile or less) with sustained winds of 35+ MPH for three or more consecutive hours. The snow doesn't have to be light, and it doesn't even have to fall—there is such a thing as a ground blizzard, which is a whiteout caused by snow already on the ground.
This storm could be a dangerous, especially for residents right along the coast. During the height of the storm on Sunday afternoon, Cape Cod could see wind gusts up to 75 MPH at times. With winds that strong blowing in conjunction with heavy snow and bitterly cold temperatures, residents on the Cape could face life-threatening conditions if they go outside during the worst of the storm. It is very easy to become disoriented during a whiteout, and people can and have succumbed to the elements after venturing a little too far away from safety and not being able to find their way back.
Elsewhere across coastal New England, blizzard warnings are in effect in anticipation of heavy snow blowing around in 30 to 35 MPH sustained winds, with gusts up to 50 MPH possible at times.
Winds will still be strong, even in those areas not expected to see any snow from this storm.
A high wind watch is in effect from the mountains of North Carolina up through Washington D.C., Baltimore, Philadelphia, and into the New York City metro area in anticipation of wind gusts reaching 60 MPH during the day on Sunday. Winds this strong could cause tree and structural damage, leading to hazardous conditions for humans and animals, as well as potentially knocking out power to thousands. Stay aware on Sunday if you're around tall trees or unstable structures, and give trucks and other high-profile vehicles plenty of room on the roads in case they tip over or lose control in a strong gust.
Given that the storm will have winds equivalent to those seen in a strong tropical storm or a minimal hurricane, high waves and a small storm surge are possible on north/northeast facing shores during the height of the storm.
Coastal flood warnings are in effect for the Massachusetts coast from Salisbury to Cape Ann, as well as from Hull to Dennis. Forecasters anticipate a 24 to 30 inch storm surge during high tide on Sunday morning, in addition to 20-foot waves. Coastal flooding is likely in low-lying areas, and beach erosion/damage to structures right on the shore are a major concern.
The National Weather Service office responsible for the coast in New Hampshire and Maine have also issues a coastal flood warning for the entire New Hampshire coast, as well as coastal Maine from the state border to Brunswick, including Portland. Communities on the shore could see "minor coastal flooding, spillover, and beach erosion" a few hours on either side of high tide at 7:00 AM on Sunday.
Air: If the snow doesn't cancel or delay your flight, the wind will. Expect major delays and cancellations at all of the major hubs from D.C. to Boston starting Saturday evening and lasting through Monday morning.
Rail: Trains will stop running if snow depth on the rails becomes too great. Amtrak will likely cancel or modify schedules north of New York City during the day on Sunday and Monday in accordance with weather conditions.
Car: If you're in an area under a winter storm warning or blizzard warning, please stay home if you can. You'll get in the way of snow removal crews if you're out on the roads, and you could risk your life and the lives of those around you (as well as your rescuers) if you get stranded during the height of the storm. This level of cold and wind is nothing to screw around with—if you get stranded, there is a real chance that you could succumb to hypothermia.
Foot: This will be a light, fluffy snow, optimal for blowing around and not at all fun for snowballs. If you have to walk somewhere during or after the storm, you shouldn't have too much trouble getting around (barring any issues from snow already on the ground). Stay indoors during the strongest wind and snow (remember that whole "whiteouts are disorienting" thing), and be mindful of any trees or power lines that might come down during stronger gusts of wind.
For all of the problems it will cause in New England, this will be an even worse storm for the Canadian Maritimes on Sunday night and Monday. According to The Weather Network, residents can expect a widespread area of 50+ centimeters (20+ inches) of snow across eastern New Brunswick, western Nova Scotia, and the western half of Prince Edward Island. Winds will also be a major factor, with gusts up to 120 km/h (75 MPH) possible on Prince Edward Island and Cape Breton (the island on the northeast tip of Nova Scotia).
The storm won't produce anywhere near as much snow as White Juan did back in 2004, but the winds could be on par with that historic blizzard. Power outages are possible (likely in rural areas) during the height of the blizzard. Also, much as it will be in parts of New England, coastal flooding, huge waves, and major beach erosion will be an issue in Nova Scotia and Prince Edward Island as the storm passes through on Sunday and Monday.
Next Week's Storm
If one storm isn't enough for you, another winter storm is likely to develop on Monday in the southeast and race towards New England on Tuesday and Wednesday as a budding nor'easter. I'll have more on that as weather models get their bearings and start producing more consistent information, likely tomorrow or Sunday. This will present as a more classic winter storm, originating in the Deep South and moving northeast, likely giving many people from Mississippi to Maine a taste of snow and ice.