A massive Arctic airmass has been building in Canada and has been the focus for the last several days in the weather community. The question was when and if it would move south. The models have come into nearly unanimous agreement this air will move south this week. The worst and core of the cold may move over Texas this weekend bringing some of the coldest temperatures in years to DFW (at least since January 2018, but maybe longer if the models are to be believed). A cursory glance shows most of the central and western Canadian prairies well below zero (-40°F+ in some areas). With an upper low tightening up in the Great Lakes, the flow around this will be enough to give the airmass the nudge to move south rapidly in waves by the weekend.

The leading edge of this massive Arctic air is actually going to move into the area tomorrow, kind of like pancake batter, moving south based on its own density. This is a very shallow leading edge of the Arctic airmass and really not all that cold yet. Our temperatures will gradually turn colder throughout the week with the coldest arriving Friday evening and may last into early next week.

Severe cold is defined at DFW as being a low temperature at or below 10°F or a high at or below 20°F. This is definitely on the table with several models showing that kind of cold. While we are not confident, yet, in cold getting that extreme, we are confident it will turn very, very cold. Temps will likely drop into the teens, if not colder, and wind chills may dip below zero at times. This is also likely to be a protracted cold spell much like Super Bowl week of February 2011. We could see more than a day of subfreezing temperatures.

What is not quite as clear is the prospects of precipitation in the cold air. Experience tells us moisture may be hard to realize in such deep intrusions of cold air. However, it does not take much lift or moisture to cause it to precipitate in that kind of cold air, and their will be some perturbations that move across the cold air. Of course any precipitation in this cold would be frozen and could potentially impact travel. More on this as we get a better handle on the latest data.

Residents of DFW should prepare now to insulate exposed outdoor pipes from the cold. If this cold is realized to its full potential, it would be more than enough to freeze and burst pipes that are exposed.