This type of cold is part of global warming. With the lack of Arctic ice, the temperature difference between the North Pole and the mid-latitudes has decreased. It is this temperature difference that drives the jet stream.
As the strength of the jet stream decreases, the Rossby waves in the jet stream increase in deviation, that is, the loops in the jet stream that let cold air penetrate farther south and warm air penetrate farther north increase. See image!
This increase in the Rossby waves has been gradual and going on for decades. For example, once upon a time, northern Florida grew oranges - no more.
Aside from this process putting the rest of Florida's citrus industry at risk, there will be numerous other economic consequences - particularly when you consider this process could lead to killing frosts occurring much later in the spring.
As some one who teaches paradoxical presentation of the earth, you appear to be going down the same path of many who do not understand that a cooling planet, in its change state, will always present with decreased polar ice, as the heat is vented from the earth due to a reduced polar atmosphere thickness and heat being pulled poleward. This creates a strengthened polar jet which dips deeply to mid latitudes to capture heat, as it is doing today.
If current charts (projections) are correct, this summer will be very short and cool for most of the Northern hemisphere as we near the thermal input-output balance where median jets of equal strength balance with polar jets. When that occurs watch as things ice up very fast. We have one maybe two years before our balance is fairly close. Until then wild swings of the polar jet will continue.