ITHACA, N.Y. — For those hoping for a pleasant warm-up after the past few days of frigid cold – sorry. A large and powerful storm system will evolve into a potent Nor’Easter tonight through Tuesday, resulting in widespread significant snowfalls and travel disruptions. A Winter Storm Watch has been issued by the National Weather Service’s Binghamton office through Tuesday afternoon.

Meteorologically speaking, this type of event is known as a “Miller Type B” Nor’Easter. What that means is a low pressure storm center in the Ohio River Valley moves eastward into the Appalachians and its circulation is shredded over the high terrain. However, its counterclockwise circulation taps into the Gulf Stream and helps conjure a second storm center over the Atlantic, transferring its energy to that storm and riding up the coast in a northeasterly direction.

What that means weather-wise is a two-pronged event for Tompkins County, with a lot of uncertainty still in the equation. The first round will consist of light to moderate snowfall spreading across Pennsylvania and into the Southern Tier this afternoon and persisting through Monday morning. From this round, do not expect more than 2-3 inches. The fact is, this bitterly cold air aloft (the airport hit -4°F this morning) is also very dry, which eats away at the storm’s edge like a sponge and limits snow development. There will likely be a sharp cutoff somewhere in Central New York between areas that get snow, and areas that get nothing because the frigid air dried out the storm’s edges. With temperatures climbing into the upper 20s today with southerly flow ahead of the low, and falling into the low 20s overnight, no ice accumulations are expected.

Graphic courtesy of NWS Binghamton.

The second round is Monday evening through Tuesday night, as a band of heavier snow rotates northwestward into the region. This is expected to be the more potent component. As the new storm develops, the oceanic air it wraps into its circulation will be moist enough to overwhelm the remaining dry Arctic air. At this point, the question is more on the exact storm path – the more to the west and to the north it moves, the more likely Ithaca and Tompkins County see a significant, heavy snowfall event. Right now, the consensus is for 6-8″ from Monday evening through sunrise Wednesday. However, the modeled precipitation totals are all over the place. There’s a 10% chance it’s 4 inches or less for this whole storm event, and there’s a 10% chance it’s over 18 inches. It will depend on if the more intense band of snow makes its way in late Monday into Tuesday, and how long it persists.

The primary impacts here are going to be from that heavier snowband makes it way in for Monday evening through Tuesday. This first round today and tonight is the type of thing your local Highway Department can keep up with and plow without much trouble; the usual notices to drive with caution and watch out for slippery roads applies here. The second wave is where the risk is. If a higher-end solution starts becoming reality, major travel impacts would be likely with treacherous driving in the hills and difficult travel on any untreated road. Temperatures will remain in the 20s during the period, upper 20s during the day and lower 20s overnight.

Graphic courtesy of the NWS Eastern Region Headquarters.

While there’s uncertainty on whether we’ll be seeing a mild or more significant event, down along the big cities of the Northeast and Mid-Atlantic, its expected to pack a heavy wallop. Travel to New York, Philadelphia, and Washington DC is strongly discouraged Monday and Tuesday as heavy snow (and in DC’s case, likely some ice accumulation) will pose hazardous travel conditions, if travel is even permitted from airports and along major highways. High winds in excess of 50 MPH are also expected along the coast closer to the center of the coastal storm as it develops.

For further notices, follow NWS Binghamton at their website or on social media. The regular weekly weather report will be issued tomorrow evening.

Brian Crandall

Brian Crandall reports on housing and development for the Ithaca Voice. He can be reached at bcrandall@ithacavoice.com.