Winter storm update: Snow and sleet flies in northern New Jersey

John Cifelli, Meteorologist | January 19, 2019 | Weather

As of 9:15 p.m. Saturday evening, snow and sleet is falling north of a line along the Mercer-Hunterdon border, through central Somerset County, into northern Union and Hudson Counties. North of this line is where accumulations will generally start. Already there is a quick inch of snow in my backyard in Hunterdon. I’ve seen reports of an inch from Morristown, Flemington, Chatham and Stockton as well. For the time being, the mix line has held in place for the last hour. That’s not uncommon at the onset of precipitation as the saturation of the entire column of air aloft above a location has a cooling effect on the temperature. A band of heavier precipitation is moving northeast from the Philadelphia/Doylestown area. As this band of precipitation moves into central New Jersey, it will bring the heaviest rates of snow and sleet for the storm, probably about 1.5 inches an hour. It will also drag the mix line north with it, as this band coincides with a push of warmer air aloft. It will encourage a changeover to sleet or rain. Whether or not that rain freezes depends on your surface temperature. Residents of northern Hunterdon, Morris, Essex, and northern Bergen Counties will be the first to see the potential for freezing rain as the warmer air aloft moves in. Further south, from roughly the 202 corridor on south, surface temperatures are at or above 32 degrees, and there will be no freezing rain here.

For additional thoughts on the forecast, refer to the previous forecast posts here and here.