A new storm system developing over the southern Plains will track toward the Great Lakes through midweek, bringing treacherous weather to much of the Midwest and Northeast. Heavy snow and icing conditions will be the main threats posed by this storm, with impacts already beginning in some areas.
Through this evening, a band of snow spanning from southern New Jersey through Pennsylvania should persist with little movement, dropping a couple inches of snow inland. This will make for poor driving conditions during the evening commute in the Philadelphia area. To the west near the center of the low pressure driving this messy weather will be another area of snow. This snow will be impacting the southern two-thirds of Iowa and even parts of northern Missouri, although this area will need to be on the lookout for a wintry mix and some freezing rain.
Now as we get into the overnight hours tonight, our storm system will become better organized as the precipitation runs into the cold, freezing temperatures pouring in from the north. This will allow for the snow to become more widespread. By the wee hours of Tuesday morning, we expect an area of light to moderate snow to develop from southern Minnesota to most of Iowa and from northern Missouri through the southern Great Lakes region and into parts of the Mid-Atlantic (especially Pennsylvania and New Jersey). Because the best lift will be near that low pressure over the Midwest, the snow will be heaviest there. Just south of that snow may be a corridor of freezing rain, which may affect Chicago but especially areas to the south and east. Some freezing rain may also be possible near the Mason-Dixon Line in the Mid-Atlantic region, but dry air should keep that isolated tonight.
On Tuesday, the Northeast will start to become more involved with this storm as the low pressure continues to track in a northeastward direction. This will allow for a band of snow to work into the region, with that band spanning from Minnesota through the New York City area Tuesday morning. Tuesday will definitely be the messiest day, with snow impacting a large chunk of the upper Midwest, Great Lakes, and Northeast. By the afternoon, snow will advance into central New England and Upstate New York. What will be interesting to watch back toward the west is the changeover from rain to snow in parts of the western Ohio River Valley, although this precipitation should be light, preventing much accumulation from occurring.
Now as the atmosphere gradually warms in the Northeast thinks to warmer air advecting in from the south, that will introduce the freezing rain threat. Numerous areas in the Northeast, especially in the I-95 corridor from Philadelphia to Boston, will experience a transition from snow to freezing rain to plain rain on Tuesday. So in the morning Tuesday, a brief period of freezing rain will be possible before a plain rain moves in across the Philadelphia area. In the New York City area, however, the wintry weather will last a bit longer, with snow likely in the morning before freezing rain takes over midday. It should then turn into rain during the evening areas. The further north you go, the more delayed this transition will be. In Boston, we anticipate the snow to begin Tuesday morning and continuing into the afternoon before rain takes over for a few hours. Based on the model data, eastern New England for the most part won’t be dealing with much or any freezing rain, thankfully.
So far we’ve focused on the major cities, but a rather widespread area of freezing rain will also become a threat inland. On Tuesday, this icy precipitation is forecast from the central Appalachian Mountains, near the West Virginia/Virginia border, through central and eastern Pennsylvania, much of New York, and much of southern New England. This means that at least a glaze of ice will be possible on most surfaces, including the untreated roadways, and as such travel is not advised.
Overnight Tuesday, our winter storm will begin to pull into Canada while warming air tracks in from the south, ushering in a transition from the wintry weather to rain across much of the Mid-Atlantic (mainly south and east of the Appalachian Mountains) and southern New England. Meanwhile in northern New England, snow will continue with some freezing rain possible. Snow will also continue before all of the precipitation clears out in upstate and western New York, the eastern Ohio River Valley, and in much of the Great Lakes. By this point in time, any snow will become light.
By Wednesday, the I-95 corridor will become dry but cold thanks to a cold front passing through. This will also lead to an increase in winds across the Northeast, with gusts over 40 mph at times. With any icy trees, branches could become knocked down, therefore knocking out power. Now in northern New England, the snow will still be coming down at a moderate clip during the morning hours before tapering off in the afternoon. Lingering snow showers will also be common across the interior Northeast throughout the day.