Also the reason for these extremely cold temperatures happening and doing so more often is directly a result of literal global warming. Due to rising temperatures (thanks to climate change caused by humans which is real and happening right now and fuck anyone who says otherwise), the Arctic sea ice has been melting more and more without replenishing itself during winter. To make matters worse, the more ice that melts, the more ocean is exposed, which absorbs (rather that reflecting like ice does) the sun’s energy, further heating up.
This rise in polar temperatures is the reason the polar vortex is currently above the US and making Day After Tomorrow a reality
For those who don’t know, a polar vortex is an area of low pressure that likes to chill around the poles (both north and south but the north is more relevant here). These areas of cold, dense air are usually kept in check by jet streams: long, narrow, fast flowing air currents caused by two masses of air that are different in density/pressure/temperature etc. meeting.
The polar jet streams in particular are caused by the meeting of cold, dense low pressure polar air and warm high pressure air from the tropics. It’s usually pretty strong, especially during winter, as the temperature gradient between the poles and the tropics is rather large. The bigger the difference, the stronger the wind, and the less likely that polar air escapes southwards.
However, due to the warming around the north pole thanks to the melting sea ice and warming oceans, this gradient is decreasing.
This results in a weaker polar jet stream, which allows the vortex to meander all over the place, such as down south into the US, bringing the cold dense air with it.
Please go forth and use this information to make sure the idiots using this cold snap as piss poor evidence that climate change isn’t real know that they’re wrong and they should feel bad. Also maybe tie them down and make them watch this video (which is where I got these gifs from) which is a good (but terrifying) explanation of how extreme weather events are becoming and will become more common as a result of anthropogenic climate change.