Winter storm update: More wet, less white

John Cifelli, Meteorologist | January 19, 2019
  • Snow accumulations reduced from previous forecast
  • Snow, sleet, freezing rain still likely for northern and parts of central New Jersey
  • 1-2 inches of liquid equivalent to fall statewide; flooding concerns
  • Arctic cold arrives Sunday afternoon, dangerous temperatures through Monday

The expected upper level configuration has shifted ever-so-slightly over the last 24 hours, allowing for our developing surface low to take a slightly more northerly/westerly track, opposed to the more southerly/easterly path expected this time Friday. As a result our rain/mix line has also slipped northward, and whereas yesterday it looked like 195 would be the initial battleground area, it will instead be the Route 1 corridor.

I think Friday’s broadcast and forecast┬ástill gives a good idea of how everything plays out. I expect accumulations to be on the low end of the ranges outlined — an inch or so of snow and sleet accumulation in Mercer and Middlesex, with gradually more as you move north and gain elevation. Sussex and western Passaic and Bergen Counties should see 6 or 7 inches of accumulation before a changeover to freezing rain and eventually rain. The surface cold gives a feather’s edge between plain rain and icing. I still expect significant ice accrual for a stripe of northern New Jersey, but I’m shifting the area where it will be worst northward, between Routes 80 and 78. A quarter-inch of accrual could mean power outages in northern New Jersey Saturday night.

Timing-wise, onset is on track with previous thinking, between 5-7 p.m. depending on where you are around New Jersey. The rain/mix line will slide north as the evening progresses. Just north of this line, snow and sleet will come down very hard. Once you look outside and see that the rate of precipitation has relaxed, you will know you’re dealing with rain the rest of the night. Whether or not it is freezing or plain rain will depend on your surface temperature at that point. Precipitation ends between 6 and 9 a.m. tomorrow morning as plain rain everywhere except for northernmost New Jersey. For those that contend with plain rain most of the night, look for possible road flooding, ponding, and creek flooding tomorrow morning. That presents more of an issue than usual as we may see a flash freeze as Arctic air arrives behind the cold front Sunday afternoon.

Temperatures will be in the 30s and 40s through Sunday morning, but once the front passes, temperatures will drop as quickly as a degree every 10 minutes. By mid afternoon we will be in the teens and 20s, and wind chill values will plummet even colder. It will be painfully cold as the evening arrives. Some parts of northern New Jersey may drop below zero, and everyone will wake Monday to below zero degree wind chills. This sudden crashing of temperatures also means that any flooded areas or puddles on roads can quickly ice over. Even though precipitation ends in the morning, be wary of ice through the day.