News Excerpt: 

After months of record-breaking warm temperatures, much of the U.S. is facing a harsh, fast-approaching blast of frigid air from the Arctic that could cause 0° Fahrenheit temperature in the mid-west and great lakes.

The concept of Arctic Blast: 

• An Arctic blast is defined by the US National Weather Service as when “very cold air masses that typically originate in the Siberian Region of Asia, cross over the North Pole into Canada and push south and east into the lower United States”.
• Typically, very cold air in the Arctic is trapped inside a high-altitude swirl of winds called the “Polar vortex”, which is surrounded by a lower-altitude band called the polar jet stream. 
• If the polar vortex gets disrupted, then the jet stream can become wavy and carry frigid air much farther south than usual in an Arctic blast. Sometimes this frigid air brings snow and ice; other times the weather is dry but bitterly cold.

• As this Arctic air is pushed into the warmer, moister air ahead of it, the system can quickly develop into serious weather — including what’s known as a “bomb cyclone” – a fast-developing storm in which atmospheric pressure falls quickly over 24 hours.
• These severe weather events usually form over bodies of water, which have lots of warmth and moisture to feed the storm.

What is Polar vortex and Polar jet stream:

• According to NOAA stratosphere experts people often confuse the polar vortex with the polar jet stream, but the two are in completely separate layers of the atmosphere. 
• The polar jet stream occurs in the troposphere, at altitudes between 5-9 miles above the surface. It marks the boundary between surface air masses, separating warmer, mid-latitude air and colder, polar air.
• It’s the polar jet stream that plays such a big role in our day-to-day winter weather in the mid-latitudes, not the polar vortex.

Conclusion: 

The debate among scientists continues regarding the precise causes of polar vortex disruptions and severe winter weather events. While some experts attribute it to climate change-induced shifts in the Arctic, the complexity of these phenomena highlights the evolving nature of climate science. The occurrence underscores the unpredictability and counterintuitive impacts of a changing climate.