NJTV Weather: Snow Coming Friday into Saturday

20150122_Precipitation-SnowMapBy Meteorologist John Cifelli

Last night’s clipper system, which spread up to three inches, mostly in southern New Jersey, has zipped off to our northeast. It didn’t strengthen much as it exited the area, and a lack of cold air behind the system allowed New Jersey to rebound into the 30s, and even low 40s in some places. The temperature map from 5 p.m. today showed how snowfall affects the surface temperature. Where snow fell heaviest in Cape May and Ocean counties, temperatures were four to five degrees colder than further north where less fell. In fact, at 4 p.m. it was 40 in Passaic County and 33 in Cape May.

Saturday’s storm now belongs to Friday night as well. The system is still on track to affect the tri-state area, but the recipe for heavy snowfall in this setup called for our “Miller A” Gulf Coast low to phase with energy from the north to keep things a little colder at the surface. That does not appear to be the scenario at this point, and with no high pressure system to our north acting to drive in cold air, and a relatively warmer air mass currently in place, this system looks more wet than white for most.

Tomorrow evening, the drive home from work should be fine. But shortly thereafter, from south to north, precipitation will overspread the state. Extreme southern New Jersey may begin as rain, but northern Salem, Cumberland and Atlantic counties and all points north will see at least a brief period of snow or sleet. The farther north you go, the later the start time tomorrow night, and the longer frozen precipitation will persist. It’s not yet clear where the advance of the rain/snow line will halt, nor how far west the precipitation shield will extend. I tend to think that without high pressure to our north and west, all of the area catches the brunt here.

The graphic shows the expected precipitation type at 7 a.m. Saturday from the RGEM model. Red is a transition area from rain to snow. Just after dawn the transition area is north of 95, with snow up along 78, snow, sleet and rain along Route 1, and plain rain south and east. This correlates well with what would be expected climatology-wise. Doesn’t it always seem like 95 is the transition area in these coastal storms?

The roads will be messy in the northern half of New Jersey on Saturday in the morning. I think central sees the change to rain as well after snow falls during the predawn hours. Northern New Jersey could hang onto the snow and sleet for the duration of the event, but that comes into better focus tonight and tomorrow. Locations that switch to rain, particularly away from the coast, could see things end as snow showers, without much, if any, accumulation. By mid afternoon on Saturday things are wrapping up, and we might even see a peek of chilly sunshine before it sets.

Unlike yesterday’s clipper, Saturday’s system will reinforce the cold over the state. We get a brief (really brief) pause with a seasonable cold Sunday, and then Sunday evening into Monday, another round of light snow arrives with a Manitoba Mauler, the third cousin of Alberta Clippers and Saskatchewan Screamers. It dives into the northern plains and trucks across the Ohio Valley, destined for a Sunday evening date with destiny on the mid-Atlantic coast. Friday to Saturday will dictate somewhat the exact path it takes, but it has a fair chance of being a significant impact on the Monday morning commute.

That’s how it looks right now, pretty much the archetype nor’easter, with snow in the favored locations, rain on the coastal plain and a transition zone along the Turnpike.