What’s new?
“During the night, the consensus on the forecasting model shifted our impending winter storm slightly south. This is a slightly cooler and snowier solution.
– These models have also come to a much better agreement on the start time, peak and winter mix transition.
—Having said that, the timing of the end of this storm system is a little foggy right now — precipitation can linger over New Jersey for most of Friday.
—I am very concerned that the ice mix (hail and freezing rain) will be the ultimate “snow blower”, especially in the southern half of the state.
“You will notice that I have adjusted my snow contours slightly to the south.” And I added an area that covers the south coast. But I am choosing to kick off any significant changes on the way to the next update.
—The result remains the same: no matter where you are in New Jersey, Thursday will be wintry and confusing.
Wednesday
Calm, though cold. Wednesday morning temperatures are in the 20s, with an icy wind pushing the thermal sensation to the few digits. The wind decreases, the sun comes out and the high temperatures reach only about zero on Wednesday afternoon. The clouds will start to rise at the end of the day.
Storm Timeline
—Thursday early morning (2 am to 6 am) … A few blows of snow will invade the Garden State. Dry air will make it difficult for these flakes to reach the ground, and only minimal accumulation is expected by Thursday dawn.
—My Thursday morning (6 am to 10 am) … A steady gust of snow will spread from southwest to northeast. Once the flakes start to fall, conditions will decline rapidly, with moderate to heavy snow likely for several hours.
—Thursday noon (10am to 1pm) … The storm’s impact continues, with heavy snow streaks causing snow at 1 inch per hour. Meanwhile, warming in the middle of the atmosphere will cause a transition from snow to winter mix along the south coast.
—Thursday afternoon (1 pm to 5 pm) … The mixing line will continue to drift to the north, while medium level warming continues. Still snowing (north) and hail (south) steadily.
– Thursday evening until Friday morning (5 pm to 5 am) … The intensity of precipitation should decrease at night and during the night. Transition to rain in the southern and coastal NJ. Downtown NJ is under a winter mix (snow, sleet and freezing rain) for most of the night. Northern NJ should maintain light to moderate snow, with some potentially mixed hail.
– Friday day (5h to 17h) … A cooler air wave will determine a final transition to more snow and hail, rather than freezing rain and rain. Previously, I expected the precipitation to end in the early hours of the morning. But I’m not so sure now – the winter mix may persist for part of the afternoon.
Accumulations
—6 to 10 inches of almost all snow to the north.
—4 to 8 inches of healthy snowfall between Philly and New York. Based on the orientation of the 00Z model, I was so tempted to raise the entire northern half of the state to a 6-10 “forecast. But the snow. Oh, the snow! I’m still very concerned that the warming in the middle of the atmosphere will force the transition to an icy mixture in the north even over the I-78 corridor on Thursday night. This will quickly end the buildup and possibly cause a light layer of ice.
—2 to 4 inches for most of South Jersey. A substantial period of mixing and freezing (due to freezing rain and hail) and dry groove will be problems south of a line between Bellmawr and Belmar. (I always wanted to mention these two cities in the same sentence!) A quarter inch of ice buildup is possible here, which is quite significant.
—0 to 2 inches to the south coast, with a quick gust of snow at first, then a mixture of winter and pure rain for the rest of the storm. Depending on the length and composition of this mixture, there may be some slight concerns about the icing.
In addition, some models are still pushing an additional 1-2 “snowfall during Friday day. Eh. Given the inaccuracy of the final time, and the uncertainty that the snow will actually stick to the ground, I chose to be conservative for now.
Coastal flooding
The tidal orientation shows about 30 centimeters of storm on Friday. This is enough to cause minor flooding in coastal watercourses for one or both high tide cycles on Friday.
Winter storm clock
No changes to our watch, in effect for the interior of New Jersey from Thursday morning until part of Friday.
What is the next?
—I can’t wait to see what the model 12Z suite does with the mix line. I want to see a good consensus on the northern edge and the timing of this heat wave in the middle atmosphere, hail and freezing rain. Only then will I feel more confident about who is going to get solid snow and who is going to be arrested.
—Expect the National Weather Service clock to be updated for warnings and alerts on Wednesday afternoon. Who will receive what will depend on the output of the 12Z model.
—The next blog update on the weather will arrive around 5 pm on Wednesday, with more details and specifications, and an updated snow / impact map.
—I’m going to post another blog update on the weather on Thursday morning with my final call.
—As always, we will have updates in the air and online during the storm.
Dan Zarrow is the chief meteorologist for Townsquare Media New Jersey. Follow him on Facebook or Twitter for the latest forecasts and real-time weather updates.