Is snow the problem, or is it what comes after? They have been monitoring a general winter pattern that has the potential to deliver snow, sleet, and freezing rain to a large part of the United States, from Texas and the Plains through the Carolinas and into the Northeast. The specifics may be a little bit iffy at the county boundary, but the general idea is a definite one: an Arctic air mass is first on the scene, followed by a storm that moves along the southern boundary of the air mass.
“This is shaping up to be the most impactful storm of the winter so far,” the potential to be the most impactful storm of the winter season to date,”” said AccuWeather Chief Meteorologist Jonathan Porter. “The risk of ice, snow and frigid temperatures is a dangerous combination.” Snow and ice are both very destructive in their own ways. Snow clogs roads and snowplows, while ice causes tree limbs and power lines to break, making roads, driveways, and sidewalks very slippery and uneven even after the storm has passed. When temperatures stay below freezing, the normal process of salt, melt, drain, and dry never gets finished. This creates a landscape that is very pretty but very dangerous, particularly in areas around bridges, shaded intersections, and secondary roads that have not been treated.
This cold is not the effect of the storm; it is the cause that prolongs the storm. This cold is not a companion to the storm; The National Weather Service has issued a warning that, Behind an arctic front,“Frigid temperatures will expand across the eastern two-thirds of the country,” and that Gusty winds may result in wind chill values dropping to potentially threatening levels. In the Northern Plains, the cold is so extreme that even such mundane activities as excavating a path, warming up a car, or taking out the trash are hazardous. In the major cities, the danger is simply one of numbers: more people out in the cold, more cars on the untreated roads, a greater likelihood that a small slide will become an hours-long traffic jam.
In the Great Lakes, the week may begin with a different intensity: lake-effect snow. When Arctic air moves over relatively warmer water, snow bands can develop and focus on the same area for hours. Some models have suggested rates of 1-2 inches per hour, with winds strong enough to change the visibility from clear to whiteout in a matter of minutes. The impact is more like a moving curtain than a blanket one neighborhood digs out under sunny skies while another is buried behind the band. The end result is that travel plans made from a regional forecast will not be viable; the forecast will be street-level, sometimes mile by mile.
In other areas, perhaps the issue may be preparation. What may be considered large amounts of snow in the Upper Midwest may be intimidating in other areas that have less equipment to remove the snow from the roads, less drivers who are familiar with how to drive in the conditions, and less stockpiles of de-icing agents on hand. In Michigan, a road commission has had to issue a warning that it is running low on salt, a reminder that winter storms are as much about logistics as they are about meteorology.
Air travel may also be where the same physics happens. Snow and ice at a few airports may extend crews and planes all over the place, leading to cancellations that go well beyond the track of the storm. Porter said that there will be more than 4,000 flight cancellations over the weekend because of the storm. For those who are trying to make sense of what actually happened in their neighborhood, as opposed to what was predicted, these interactive tools can be used to help the experience become more tangible in terms of numbers, such as the amount of snowfall in a given area. However, the bigger picture is less about the inches and more about the timing, as in how long the cold air takes to get there, and how winter becomes a long game played out on slow-melting streets.
