By Meteorologist John Cifelli
As of mid afternoon, our Super Bowl evening winter storm is located in the upper Midwest, traveling across Illinois and Indiana as it heads toward the Mid-Atlantic and northeast. Radar returns show the eastern edge of steady precipitation edging into central Pennsylvania, although there have been reports of small flakes falling lightly as far east as Saylorsburg, Pa. already — about 25 miles from the border of Warren County.
Although we could see spotty pockets of flurries before the sun sets, it’s after 6 or 7 p.m. that we can see accumulating snow begin to fall. These first flakes are associated with the warm front ahead of the approaching surface low, and this surge of warm air will mean little if any accumulation for southern New Jersey before a changeover to plain rain. Already, temperatures are in the upper 30s along and south of the Atlantic City Expressway, and along the shore all the way to Sandy Hook. Dewpoints are still relatively low, so there will be some surface cooling as the air mass saturates, allowing for some snow before the inevitable and permanent changeover.
Further north, snow will remain the dominant precipitation type longer, although a continued northward trend for our storm track means that everyone, perhaps even the I-80 corridor, will see a mixed bag of precipitation. The critical question that remains is when does the changeover happen, and how much frozen precipitation falls before this changeover. I am not making any changes to the forecast, although I feel confident saying that the more northerly projected track, coupled with surface temperatures warming near 40 today across much of New Jersey means the lower bound of the snowfall range is more likely, and the area of greatest icing concern is shifted north a touch. The Route 1 corridor, northern Monmouth, Staten Island, Queens and Brooklyn are more likely to transition to plain rain more quickly, while icing is an increased threat north of 78 into Bergen County. This is in reference to yesterday’s forecast map.
Even parts of New Jersey who wake to plain rain and temperatures above 32 degrees may find slippery spots, because despite surface air temperatures above freezing, the physical surfaces themselves — roadways, sidewalks, railings — have all been well below freezing for a long period of time. Just because the air in contact with them is 33 degrees doesn’t mean these surfaces will be. So be careful from Mercer-Monmouth north if you are on the roads in the morning.
So, to summarize, as usual, it is all about track. In this case, just like the blizzard that wasn’t last Monday night, 50 miles makes the world of difference. I think that this storm will be a high impact event for travel tomorrow morning in the northern half of the state, with at least a couple inches for the northwest suburbs of Philly through Mercer and Monmouth counties northward, with increasing significance the further north you go. Things are winding down by noon, with perhaps some snow showers on the tail end of things as cold air filters back across the state in wake of the storm.