The winter storm we’ve been tracking for nearly a week now is on the doorsteps of the Northeast, and has already produced heavy snowfall across much of the Midwest, including cities like Chicago. Over the last 24 hours our team has been watching mesoscale guidance and current observations closely, and it has become apparent things have trended to the warmer side.

Due to these last minute trends, we have updated our snowfall map to reflect the latest changes. The biggest change to note is that the changeover from snow to sleet/ice to rain will happen much faster across the I-95 corridor. This is in part due to precipitation coming in later and allowing things to warm up first along the coast, and also due to our low pressure likely being situated slightly north and west than what we originally anticipated.

We still expect a very sharp gradient, however. Areas just north and west of I-95 and the major cities will quickly go from a coating to 1 inch of snowfall to 2-4 inches to 4-8 inches over the span of only 50-100 miles. Some locations across interior Pennsylvania and southern New England may have a several inch difference in snowfall totals just over the course of a few miles. Elevation will likely be key.

We still expect a large swath of 1-2+ feet of snowfall, but now centered over extreme northern PA, northern Upstate NY, and then across northern VT, NH and ME. Widespread amounts of 18-24 inches are expected with the highest elevations possibly seeing as much as 30-36 inches (although localized). Much of this heavy snow will come overnight and into the early hours of tomorrow.

Icing is also still expected to be a major issue across the Northeast, but we’ve shifted the worst of the icing to the north and west of I-95 now. Central PA as well as southern New England can expected to see some nasty ice and sleet totals, with very tricky conditions overnight tonight and early tomorrow morning. We’ve also extended that threat up into parts of northern New England across MA, southern NH/VT and coastal ME. Up to a quarter inch or more of ice will be possible after a heavy thumping of snow.

Lastly regardless of what type of precipitation falls a flash freeze is still expected across the entire region, including down into the Mid-Atlantic. Areas across I-95 that will reach up into the 40’s and possibly 50’s late tonight and early tomorrow will quickly snap cold once precipitation passes. Many of these areas will be dealing with lower teens and single digit numbers come Sunday night and Monday morning. Interior areas across the Northeast will dip well below that, likely going sub zero. Roads and wet surfaces that freeze over into your Monday will make for a hazardous morning commute.

More updates on Twitter throughout the day and night – Stay with us.


Scott is the founder and CEO of WeatherOptics Inc, which he started as a weather forecasting content platform in 2010. In 2016, after gaining a substantial following, WeatherOptics began servicing the private sector using impact analytics driven by historical weather data. Since this pivot, Pecoriello has led the effort to combine consumer, business, utility, and weather data in order to redefine how WeatherOptics could change business perspective on the weather. As founder as well as the director of all day to day operations, Pecoriello has proven WeatherOptics to be an effective, fast-growing data analytics company that is actively changing the way businesses think and react to the weather.

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