Major blizzard affecting 100 million people in the Midwest and Northeast

What appears to be the most impactful winter blizzard to date has set its sights on dumping snow all the way from the Midwest to the Northeast, impacting more than 100 million people. Some cities can be buried up to 45 centimeters of snow early next week.

Cities from Chicago to Cleveland to Washington, DC to New York are watching and waiting to see what the storm will do as it slides east from Sunday through Tuesday. This is the same storm system that soaked parts of California with no less than 15 centimeters of rain and more than 100 centimeters of snow last week.

Right now the storm is in the southwest and moving east. At the same time, the horrific cold has engulfed the Great Lakes and the Northeast, where parts of New England have chills as low as 20 degrees below zero.

This cold air carries both the promise of a major blizzard and the complication of perhaps too much cold. That’s because this cold air is associated with an atmospheric block. The strength of this block will determine whether Washington, DC will be buried in heavy snow or if the rose will land near New York City and southern New England.

In other words, will this block suppress the assault course south or make the storm crawl north? At this point it is too early to know. So far, there has been almost no snowfall in Washington, DC this winter, at just one-third of an inch.

To block or not to block, that is the question. Or really … how much will this block, prevent this storm from moving northeast? The most important area is the confluence on the northeast. Euro has it strong. Other models are less bold with the confluence. Is the truth somewhere in between? pic.twitter.com/ZdKkgehiQf

– Jeff Berardelli (@WeatherProf) January 29, 2021

What we do know is that Saturday night and Sunday there will be heavy snowfall in the Midwest and the Ohio Valley, from Chicago to Cleveland and surrounding areas. In all, the heaviest snow tire should dump 6 to 12 inches by Sunday night, perhaps including Chicago, Indianapolis and Columbus.

On Sunday, the storm will move toward the east coast, spreading snow to parts of Virginia and southern Pennsylvania. In an attempt to undermine the cold-air block, the storm will transfer its energy to a developing coastal storm along the North Carolina coast. The snow can be heavy at times in places like Washington, DC

Now comes the tricky part. Is the storm shifting east toward the sea, trapping the cold air in the Washington area and the heavy snowfall between DC and Atlantic City? Or is the storm moving northeast, burying New York City, Providence, and maybe Boston in more than a foot of snow?

It’s too early to be sure. But it looks like the blocking scenario will make this a lengthy event with some cities seeing 36 hours of snow from Sunday through Tuesday. Anyone who gets stuck under the heavy tire is likely to pick up 12-18 inches, with insulated spots close to 20 inches.

If the snow reaches New York City, it would likely start early Monday morning and then reach Providence Monday afternoon. The storm should leave on Tuesday evening.

Below is a comparison of two models showing two different possible outcomes. The first is Friday morning’s US GFS model showing robust snowfall from Washington, DC to New York City. Far below that is Thursday night’s European run, which shows the heavier snow slipping south of New York City and cutting through eastern New England.

The details will become clearer once a particular city is within 48 hours of the storm’s arrival. So stay tuned …