After brutally cold temperatures and snow covered much of the east coast last week, we’re dealing with quite a different storm system this week – Not only in precipitation type but also in size & scope of impact. A weak and jagged low pressure is currently centered over the northern Great Lakes spreading snow across a good portion of the upper Midwest with scattered rain showers further to the south and east. As this low weakens, a more potent area of low pressure will develop further to the south, allowing arctic air to crash behind our system and change most of what starts as rain over to freezing rain, sleet and snow.
In some respects, this is quite unusual. In the meteorological world, back-end snow seldom works out, as arctic fronts usually lag far enough behind storm systems to make changeovers either brief or nonexistent. This particular scenario though will allow our arctic front to catch up to the main batch of precipitation, and lead to quite a mess for many.
All major cities from Minneapolis to Chicago to Columbus to Syracuse to Albany are likely to be impacted by this storm, with each city receiving a variety of precipitation. During the day today, most of what falls will be pretty basic – Light snow across the upper Midwest and a bit of rain and mixing. Once our second area of low pressure takes over to the south though, a new batch of precipitation will move northward and crash into our arctic front, leading to a batch of moderate to heavy freezing rain from Memphis to Kentucky to Indiana and up into Detroit. Enough cold air will work its way into the upper atmosphere that many of these locations that start as rain and changeover to freezing rain, will then end as a brief period of moderate snow. Light accumulations are possible.
As that frigid air continues to catch up to the precipitation however, the changeover to snow will become quicker and quicker, eventually leading to a swath of heavy snow stretching from the northern suburbs of Pittsburgh, through Buffalo, Rochester and Syracuse, and then up into Burlington and northern New England. As much as a foot of snowfall will be possible, with some localized areas receiving as much as 18 inches. A bit further to the south and east, while we aren’t anticipating a big snowstorm, freezing rain could become a big problem.
Warmer air overhead with colder air on the surface will allow precipitation to fall as rain, but then freeze at ground-level. Some mesoscale guidance is starting to print out half an inch or more of freezing rain, leading to travel headaches and nasty conditions outside.
While the east coast will remain mostly spared this go around, places as far south as northern Mississippi and Alabama could be dealing with some freezing rain and snow later tonight and early tomorrow. By Saturday evening and overnight, most of the rain, snow, and freezing rain should be out of the country, with very cold temperatures following.
In fact, our team of forecasters are becoming concerned about a possible “rapid freeze” behind this storm, with a wild temperature gradient that will have coastal areas from Washington DC to Boston in the 50’s and 60’s tomorrow night, and then 25-35 degrees colder and well below freezing less than 24 hours later.
This means that major cities along the coast, and even areas further inland, who see rain or freezing rain tomorrow night and Saturday could see a rapid freeze by Saturday evening and night. The interior Northeast and New England becomes brutally cold as well, with temperatures dipping below zero across a large portion of the region.
After this system clears out, we begin watching another one early next week, but this time we’re keeping an eye out along the coast again. Could be a sneaky storm. Details tomorrow.