1/29 PM All Zones: Snow likely on Tuesday, especially north

On the heels of a weak low pressure system, which passed offshore on Monday morning, another clipper system will be approaching the area from the northwest. Originating in Canada, the system is tracking rapidly southeast and swinging quickly through New England on Tuesday. Moisture and lift associated with the storm will advance east/southeastwards into the region on Monday morning.

Forecast models have come into better agreement on the timing of the system’s approach, with bands of snow approaching the Northeast during the mid morning hours — but likely just after the morning commute. Still, light snow will begin from west to east and will become fairly widespread throughout NJ, NY and CT during the mid to late morning hours.

While snowfall intensity will generally be light to moderate, consistent precipitation and cold temperatures will lead to light accumulations throughout the area. Some bands of more steady moderate snow may also traverse the region during the late morning and early afternoon hours, especially in Northern NJ, potentially the NYC Metro and Southern New England.

Today's NAM valid for 2pm on Tuesday shows a potent 850mb jet streaking towards the area, helping to tap into Atlantic moisture and increasing snowfall rates somewhat.

Today’s NAM valid for 2pm on Tuesday shows a potent 850mb jet streaking towards the area, helping to tap into Atlantic moisture and increasing snowfall rates somewhat.

These bands will be aided by a strengthening low level jet, particularly at the 850mb level, which helps strengthen support for precipitation. While the signal for banding isn’t particularly strong or impressive, the overall precipitation signal is. So moderate snowfall intensity is possible for a time during the early afternoon in the aforementioned areas.

A dry slot will work northwards throughout the afternoon hours, helping to taper off snow across Central NJ, working northwards during the mid afternoon hours with snow persisting only across New England by the time evening arrives. Snowfall accumulations should be fairly uniform north of Trenton, NJ — with 1 to 3 inches of snow possible in Northern NJ, NYC, Southeast NY and CT. Southern zones may be too far south to see any snow at all.

Today's RGEM model valid for Tuesday afternoon shows the clipper transferring to a low off the coast. This may enhance snowfall rates a bit in NYC, LI, N NJ, SE NY, and CT (Tropical Tidbits).

Today’s RGEM model valid for Tuesday afternoon shows the clipper transferring to a low off the coast. This may enhance snowfall rates a bit in NYC, LI, N NJ, SE NY, and CT (Tropical Tidbits).

The one way the amounts may not be completely uniform is the way the clipper transfers to a low off the coast. Notice how in the image above, we see a kink in the isobars off the coast — this along with the 850mb jet helps a secondary low pressure system form off the coast, which can enhance lift and moisture for increased snowfall rates. But often times during these transfers, there is subsidence between the initial lift to the west with the primary low, and the new lift further east with the coastal low. This may mean that some areas in Central NJ may only pick up a trace to 1″, rather than the 1-3″ that other areas see. There’s also still a chance this transfer occurs a tad further northeast, leading NYC and LI to get a tad less snow as well, keeping areas further N and NE in the higher amounts. But as of now, we do think this coastal will take over in time to get N NJ, NYC, and LI into steady snow during the afternoon.

As usual, these amounts may lean towards the lighter end of the range near the coast and in the city. Regardless, tomorrow will have a true, wintry feel with light to moderate snow falling for a good chunk of the day.

This article was written and edited by John Homenuk and Doug Simonian