As a cold front moves through, this will set the stage for a fresh batch of cold air to sit over the Northeast region on Saturday as showers and thunderstorm begin organizing across the southern United States. By Saturday night our fast moving storm system will spread rain across much of the southeast and Mid-Atlantic as snow begins to breakout from Ohio to southern PA.
As this happens late Saturday and Saturday night, our storm system will begin to rapidly strengthen as it exits the coast, producing a swath of moderate to heavy snow either just along I-95 or just to the northwest. This is where the forecast becomes unclear.
Above we have two different models – The top model is the GFS (Global American Model) and the bottom is the NAM (Mesoscale American Model). There’s a solid 50-100 mile difference in the placement of the low pressure, with the NAM showing our low further to the north with heavier snow from New York City back to Syracuse, while the GFS shows our low further to the south with snow cutting off to the south of Albany. Another important difference is the temperature profiles. The NAM is further north and colder, while the GFS is further south and warmer.
During the time the storm will be impacting the region, our cold air from the cold front moving through tonight will be stale and winds from the south will allow temperatures to warm up near the coastline. This is why we’re concerned about more mixing near the coastline. With that said, the NAM and ECMWF (Global European Model) are in agreement on a low pressure both further to the north and colder. In the end it will come down to the exact track, strength, and wind direction near the coastline. Our updated forecast as of Friday evening goes as follows:
Much of the region will see a quick 1-3 inches of snowfall, but we expect a swath just north of our rain/snow line to see as much as half of foot of snowfall by Sunday. As of now we expect the heaviest snow to fall just to the north and west of the I-95 corridor. Allentown PA to the northern NYC suburbs and into Boston should see between 3 and 6 inches of snowfall, while places along the I-95 corridor and to the southeast will see some mixing during the storms peak with between 1 and 3 inches expected. The interior should see some snow as well, although mostly light. State College to Syracuse to Burlington will be on the very northern edge of the storm, and should pickup a quick coating to an inch. This is still a very uncertain forecast, especially in the I-95 corridor because of the marginal temperatures forecast.
By Sunday evening, our storm is out of here and temperatures begin to rebound once again. We expect more warmth similar to today by next week, so much of the snow that falls this weekend will melt within a few days.