Garrett’s Blog: Displaced Arctic Air
The global pattern of troughs and ridges oscillates quite a bit during the winter months. Since the amount of incoming solar radiation from the sun is diminished the polar jet stream will often take on a highly amplified pattern which drags air that is typically bottled up in the arctic down south the latitudes that typically do not receive extreme cold air.
There’s a large blocking ridge of high pressure that was positioned around Iceland which forced the jet stream to take a southerly track as opposed to a more typical westerly movement. The same pattern set up back in 2011 when we saw temperatures as low as -18. The neat thing about highly amplified patterns is that the bitter cold air in the unusually deep trough causes extreme warming in the ridges. For example, both Iceland and Alaska are running above normal.
Additionally with cold air, the moisture content is usually dry leading to more dry skin, house fires which spread faster, & infectious diseases which transmit easier (cold and flu).
The problem with global patterns like this is that they tend to repeat themselves and are difficult to change on a large-scale. In other words, yes… it’s cold now and no… it’s probably not going to be above normal for an extended stretch until we’re out of winter.