Dangerous, potentially historic cold continues through this weekend
Coastal low to bring accumulating snow Wednesday night into Thursday
The coast will see heaviest snow and battering seas
We find ourselves with a new round of winter weather during the first week of the new year. A powerful coastal low will climb the eastern seaboard Wednesday and Thursday, spreading snow across New Jersey. This powerful storm will lash the coastline with large waves and strong winds, adding beach erosion concerns to the mix. In the wake, our midweek storm will unleash arctic cold across the northeast and mid-Atlantic. Temperatures on Friday and Saturday will plunge below thermometer readings experienced the last couple of days.
Our current blast of arctic air has pressed all the way to the Gulf of Mexico. It is pretty amazing to see Hard Freeze Warnings issued by the National Weather Service from the Florida panhandle all the way to Galveston, Texas. This dramatic push of cold air has created an area of baroclinicity — a strong temperature gradient favorable for development of low pressure — across Florida and the northern Bahamas. Usually, our wintertime nor’easters are born off the Atlantic seaboard between the Virginia Capes and South Carolina. With the press of Arctic air so far south and east, this unique developing storm will form much further south in the northern Bahamas on Wednesday, and will actually have some tropical characteristics with it as it approaches our latitude.
We will remain frigid and clear through the day Wednesday, under the influence of a powerful high pressure center anchored over the center of the country. Clouds develop and thicken through Wednesday evening, and snow will spread southeast to northwest across New Jersey later in the night. Snow will be steadiest Thursday morning, before winding down and ending around nightfall Thursday. The low pressure center is expected to remain well off the coast, therefore the Jersey shore will have the higher snow totals. Lesser amounts will fall the further north and west you are from the coastline.
The usual uncertainties exist at this juncture. Exact track will dictate how much falls, as New Jersey is currently expected to be on the western periphery of the precipitation shield. The rapid, dramatic deepening of the system can actually consolidate and tighten the spatial area of the precipitation shield. This is especially possible in this scenario because it is so dry in the antecedent air mass and will remain so in the areas immediately outside the influence of this system. As cyclogenesis has not yet occurred and the low isn’t yet formed, there are plenty of timing discrepancies between various models. It’s like snow can began as early as Wednesday evening, or as late as daybreak Thursday. Track will be dictated by the exact interplay of several mid-level areas of vorticity and upper level jet stream features. As usual how these features interact is fragile and delicate, and subtle differences have dramatic effects on the realized weather across New Jersey. All the more so when you are talking about an area of low pressure that would qualify as a category 3 hurricane if it was warm core and tropical in nature. Hopefully these subtleties can be ironed out as cyclogenesis occurs and the upper level interactions begin to play out tomorrow. The bottom line: Wednesday night and Thursday has been a forecast period in flux, and will continue to be so for the next 24 hours.
What is set in stone is what comes after — another 48 hours stretch of brutal cold. Look for temperatures near zero, and wind chills well below on Friday and Saturday. If we get a fresh snow pack statewide, it will only serve to reinforce the latest arctic blast.
Snow totals will be highest along the coast regardless of exact track. What remains yet to be seen is if significant accumulations will be limited to the coast, or if they can spread further westward across the rest of the state. For now it looks more like the former, but the aforementioned uncertainties will have their say as the forecast develops over the next 24 to 36 hours. Expect 3 to 6 inches from Sandy Hook south through interior southern New Jersey. A bit less will fall along and north of the Route 1 corridor. The heaviest totals will be along the southern coast, where up to 8 inches looks likely for Cape May and coastal southern New Jersey. I expect the precipitation gradient to be dramatic, going for several inches to very little over a short distance.