I talked to a store owner the other day and he explained what he saw in the news recently about the Polar Vortex.
He said the typical west to east weather pattern flow of the North America was being slowed down because of what's going on in South America where it is hotter than ever in their summer season.
These changes in temperatures means changes in pressure, so when the northern hemisphere air slows down because of what's going on in SA it sort of stalls and gets sucked southward, and that pulls the arctic air rushing in after it.
Not the current weather pattern below, but a nice graphic.
Jan 28, 2019
"Fractured" polar vortex brings arctic cold snap
https://www.northcountrypublicradio.org/news/story/37911/20190128/fractured-polar-vortex-brings-arctic-cold-snap
Stay warm.