A strong low pressure system, developing off the coast of the Carolinas, will move northward on Friday and Saturday while developing into a significant Nor’Easter. This storm system will move to a position off the Mid-Atlantic Coast on Saturday, pushing bands of heavy snow into New Jersey, New York City, and Long Island. Conditions are expected to rapidly deteriorate across Southern and Central New Jersey during the evening on Friday, with travel becoming extremely difficult and dangerous on Saturday.
The northern extent of the bands of heavy snow remain in question, with a tremendous cutoff in snowfall expected from south to north. Forecast models indicate the potential for gradient of almost 18 inches of snow in less than 25 miles near the latitude of New York City. Confidence is much higher in prolific snowfalls to the south of New York City, across Southern and Central New Jersey.
Where is the storm now, and how is it developing?
A powerful mid and upper level atmospheric phase is occurring across the Mississippi River Valley, causing a tremendously powerful upper level low pressure system to develop. This is forcing an initial low pressure to move northward toward the Southern Tennessee Valley. This storm will redevelop off the coast of the Carolinas later Friday into Saturday.
Very impressive atmospheric dynamics are occurring with this storm system. Tremendous amounts of moisture, lift, and energy in the atmosphere are all leading to a very impressive and powerful storm system. In addition, these same dynamics are wreaking havoc on forecast models. This same storm system will push a surface low northward toward the Mid Atlantic coast on Saturday.
— Ian Livingston (@islivingston) January 22, 2016
Eventually, the surface low will get to a latitude near Ocean City, Maryland, stall, and then begin to move eastward. During this time frame, bands of very heavy snow are likely to pivot into our region.
What hazards could the storm bring to our area?
This storm is expected to bring a plethora of hazards to the areas that are hardest hit. In Central and Southern New Jersey, prolific snowfall totals are expected. Most forecast models agree, in that area, that liquid equivalent amounts of 1.50-2.00″ (or in some cases higher) will fall. This supports upwards of 15 inches of snow, with the potential for 18 inches or more. Very heavy snow for prolonged periods of time will create near-zero visibility, whiteout conditions, and very dangerous travel.
Farther north, the cutoff in snowfall will lead to greatly varying impacts over short locations. But generally, up to the New York City Metro, periods of heavy snow are likely on Saturday. Travel will be quite difficult while snow is falling. The impacts of snowfall are expected to drop off considerably once one travels north of New York City, into Southeast New York and Connecticut.
The developing strong Nor’Easter, and high pressure to the North of our area, will additionally lead to a tremendous pressure gradient. This will help funnel in strong east/northeasterly winds, which will be especially prevalent along the New Jersey shore. High surf and strong winds will lead to the potential for dangerous waves, beach erosion, and coastal flooding. The potential exists for flooding into the back bays of the New Jersey Shore.
Wind gusts may exceed 50 miles per hour at times near the coast, and even a bit inland, from New Jersey to New York City and Long Island. This will create blizzard conditions at times — hence, the Blizzard Warning — no matter how much snow actually falls. Visibility will drop near zero during heavy snow.
What are the uncertainties that still exist with the storm?
The main uncertainty that still exists is the exact track of the storm system — and the resulting placement of the heaviest snowfall gradient and axis. Even this morning, forecast models are in disagreement on exactly where this gradient will fall. However, a slowly developing consensus seems to be emerging that this gradient will fall somewhere near New York City’s latitude, running westward along the I-78 corridor in New Jersey.
This will lead to tremendous uncertainty in this area, and very high variance in snowfall totals over short distances. For example, this mornings GFS model indicates the potential for 5″ of snow north of I-78, and 15″ of snow just several miles south of it, with over 20″ in parts of Central NJ.
Forecasting and pinning down exactly where this gradient will fall will take patience, analysis, and time — as we probably won’t have a better idea until later this afternoon or evening. It may even take until during the storm system for mesoscale processes to reveal themselves.
What preparations should I take, and what do I do now?
General winter storm preparations should already be underway. Be sure to take and loose outdoor objects inside, as wind gusts may blow them around or off your property. Remember to prepare your vehicles and property for snowfall, plowing, and severe winter weather. Have a plan in place in case you lose power; heavy snowfall and wind can cause widespread power outages.
If you live near the New Jersey Shore, be sure to have a plan in place to protect your property for coastal flooding. In addition, prepare for wind gusts over 50 miles per hour at times as well as heavy blowing snow. Have a plan in place in case you lose power, or need to leave your location.
Other than preparing, all that’s left to do now is wait for some new weather model data. This data will help us pin down the forecast, and the location of the heaviest snowfall bands and gradients. This will help us gain confidence in the forecast moving forward.
Additional updates are scheduled for this afternoon, with information on the latest weather data as well as a video briefing on the storm with more intricate details on timing, impacts, etc.