12:50 PM | *New Jersey snow special today associated with a “norlun” trof…dusting to an inch or so possible as far inland as Philly and immediate suburbs…snow threat continues for Sunday/Monday*
Paul Dorian
Surface analysis features an inverted (“norlun”) trof axis extending northwestward from low pressure over the western Atlantic to New Jersey; courtesy NOAA
Overview
Accumulating snow is falling over central and southern New Jersey and some areas may end up with 4 or 5 inches by the time the evening rolls around and a dusting to an inch or so is possible as far inland as Philly and its immediate suburbs. This localized snow event is associated with an inverted (“norlun”) trof axis that extends northwestward to New Jersey from a western Atlantic Ocean intensifying low pressure system. Looking ahead, a major storm will head from the eastern Pacific Ocean to Texas by the early part of the weekend and then it’ll make a move towards the North Carolina coastline. Given this track, significant accumulating snow will likely be the result from Oklahoma-to-North Carolina and even as far north as the southwestern part of Virginia. After that, there are some signs that this storm can ultimately have an impact on the I-95 corridor region in the Sunday/Monday time frame, but we’re still a bit too far away to be certain.
Snow falling in two different regions today of the Northeast US/Mid-Atlantic from two different atmospheric processes (upper-level energy, “norlun” trof); courtesy NOAA
Short term - the ”norlun” trof
An impressive wave of energy in the upper atmosphere is generating snow showers across West Virginia, western Maryland and western Virginia and some snow is even being reported just to the west of Washington, D.C. Snow showers associated with the upper-level low can result in a quick dusting or so later today or early tonight in the DC metro region and perhaps generate some slick spots on the roadways.
Meanwhile, an inverted trof axis is extending northwestward from a low pressure system over the western Atlantic Ocean to the New Jersey coastline. This type of trof axis is sometimes referred to as a “norlun” trof and it can be associated with small or meso-scale heavy snow bands and the possibility of a relatively quick 4 or 5 inches of snow. The best chance for heavy snow bands today will take place across central and southern New Jersey; especially, in coastal sections, but there can even be a dusting to an inch or so in Philly and its immediate suburbs to the south/southwest (e.g., Delaware County, Chester County). The snow associated with the “norlun” trof should wind down by the evening rush hour as the western Atlantic Ocean low pressure system pulls farther away from the coastline.
Some signs are developing in computer forecast models for a more northward push of the late weekend storm system. For example, the Euro model between yesterday’s run and today has shifted slightly north with the upper-level low and a tad to the west with the western US ridge axis…both of which favor a more northward late weekend storm track…stay tuned to see if this trend continues. Courtesy ECMWF
Longer term…storm threat continues
A storm will head towards the southern California/northern Baja region from the eastern Pacific Ocean on Thursday and then this low pressure system will likely re-emerge over Texas by the early part of the weekend. From that location, all signs point to a general west-to-east track of this storm to a position near the North Carolina coastline by the second half of the weekend. Given this track, copious amounts of rain will fall in the Deep South later in the week and into the weekend and there can even be some severe weather to deal with in that part of the country. Farther north, along and just to the north of Route I-40, significant accumulating snow is likely from Oklahoma-to-North Carolina and the significant accumulating snow can even extend as far north as southwestern Virginia. In fact, some spots of western North Carolina and southwestern Virginia could see 1-2 feet of snow from this significant weekend storm system.
It is still unclear as to what kind of impact there may be in the DC-to-Philly-to-NYC corridor from this weekend storm, but the threat for accumulating snow is certainly still on the table. The general consensus by computer forecast models up till now has been for this storm to stay primarily to the south of the DC-to-Philly-to-NYC corridor. However, there tends to be a southeast model bias with respect to east coast storm positioning when several days out from event time and some signs that suggest a trend to the north by the models may be about to begin. In addition, there are “atmospheric pattern” reasons that suggest a “farther north” track is possible so stay tuned.
Meteorologist Paul Dorian
Perspecta, Inc.
perspectaweather.com
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