Thursday’s sunshine will turn to clouds, snow, and rain all day Friday; 4 to 6 inches of snow accumulation is expected for part of New Jersey.

Timing

The start of the snow should hold off until about sunrise on Friday (around 7 a.m.), and will spread from southwest to northeast through the morning. As temperatures slowly climb above freezing through Friday morning and afternoon, the snow will transition to a cold, uncomfortable rain for most of the state. The heaviest, steadiest precipitation will occur from late morning through early evening on Friday. As temperatures drop again on Friday night, any rain will likely transition back to light snow. The final snowflakes are expected to fall sometime early Saturday morning (just after midnight).

Accumulations

This is a tricky storm to forecast definitive snow totals, because of the expected transition from snow to rain (and back again). The past few model runs have shown the coldest temperatures to be in the northwest corner of New Jersey (no surprise there). So that’s where we’re going to put the highest snow totals: 4 to 6 inches is expected across a good swath of Sussex, Passaic, Morris, Warren, Hunterdon, and Somerset counties. South and east of that “sweet spot”, the transition from snow to rain will halt snow accumulation at some point. So we’ve limited snow accumulations to the 2 to 4 inch range along the NJ Turnpike (north of exit 7A). About an inch or two is expected for Monmouth and Ocean counties down through most of South Jersey. And along the south coast, snow totals will be less than an inch.

No matter what is falling from the sky - snow, rain, or something in between - roads are likely to be icy, snowy, slushy, and/or wet. In any case, you should expect significant travel problems all day Friday, including the evening commute.

Warnings & Advisories

Complications

There was one advantage to the ridiculously cold temperatures in February. With temperatures well below freezing for weeks at a time, it was very clear that any impending storm systems would produce only snow.

But a March storm is a very different story, especially with temperatures expected to hover at or just above freezing. Complicating matters is that the majority of this system will impact New Jersey during the daytime hours on Friday. Temperatures during an overnight storm would likely stay cold enough for all snow, but this daytime storm will feature slowly warming temperatures and that variety of weather concerns from snow to cold rain.

Furthermore, there are some outlier models (Euro and Canadian) that put the heaviest snow totals further south than my forecast. That would put about 6 inches of snow around Mercer, Middlesex, and Monmouth counties. Yikes, that's a big difference! However, I suspect these models are not handling the warming temperatures well. While this area of the state would likely see the biggest totals if the precipitation stayed frozen all day, the changeover to rain will save Central Jersey from the big snow totals.

So I’m comfortable with my forecast snow total map at the top of this article, especially since there is pretty good agreement among area meteorologists of snow totals, timing, and coverage. However, confidence remains moderate at best, given the complications I’ve mentioned here. If your plans on Friday are extremely sensitive to weather conditions, I'd recommend you keep an eye on the forecast in case it changes in the next 24 hours, and stay tuned for the latest updates during the storm on Friday.

The Weekend Ahead

As the snow ends on Friday night through early Saturday morning, skies will start to clear. Saturday looks like a pretty nice day, with partly sunny skies and highs approaching 50°. Early Sunday morning, we’ll see some light snow showers visit the state (especially in North Jersey). And then Sunday will be sunny, but cooler, with highs scaling back to around 40°.