Global warming disrupts polar vortex. But, what is it?

Parts of the United States are experiencing the 10th and coldest polar vortex event this season. Weather forces in the Arctic are combining to push the chilly air into the US and Europe

Hyderabad: The term ‘polar vortex’ usually refers to the gigantic circular upper air weather pattern in the Arctic region. It is a normal pattern that is stronger in the winter and keeps some of the coldest weather bottled up near the North Pole.

But at times some of the vortex can break off or move south, bringing unusually cold weather south and permitting warmer weather to creep up north.

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This week, parts of the United States are experiencing the 10th and coldest polar vortex event this season. Weather forces in the Arctic are combining to push the chilly air into the US and Europe.

With record snow in New Orleans and drought and destructive wildfires in southern California, this winter has not been normal. The latest projected cold outbreak will bring bone-chilling temperatures to the northern and central plains for several days.

Wind chills dropped to minus 51 degrees Celsius in parts of North Dakota and minus 46 degrees in parts of Montana. Wind chills were expected to dip even lower. “Frostbite and hypothermia will occur if unprotected skin is exposed to these temperatures. An extended period of freezing temperatures could cause ruptured water pipes,” the National Weather Service warned.

Meteorologists expect strong winds to make the cold feel even worse. Every US State but Hawaii, California and Florida have some or all parts forecast to have a good chance of wind chills of 20 degrees or below sometime next week.

Some experts say disruptions to polar vortexes are happening more frequently because of a warming world.

A warmer Artic gives more energy to atmospheric waves that can drive weather patterns, making the waves more likely to disrupt the vortex and move colder air south into lower latitudes. Despite the unusually cold winter across the United States, the world remains in an overall warming pattern.

Earth’s average overall temperature set yet another monthly heat record in January. It was the 18th month of the last 19 that the world hit or passed the internationally agreed upon warming limit of 1.5 degrees Celsius above pre-industrial times.