Extreme cold weather in North America and blistering heat waves in South America have been making headlines over the last few days with record-breaking conditions on either end of the temperature scale at the extreme weather conditions around the globe.
Some cities like Milwaukee, St Louis, and Chicago experienced sensory temperatures that dipped to below minus-50 degrees. Around 14 counties in the state of New York declared a state of emergency due to the frigid conditions, closing schools and airports. More than 500 passengers taking regular train services in Chicago were left stranded in their compartments for 14 hours when the trains. They were traveling in got stuck in ice and snow.
Experts attribute the rush of cold air due to something called a distorted polar vortex, which is a circulation of strong, upper-level winds that normally surround the northern pole in a counter-clockwise direction. Normally a polar low-pressure system keeps the bitter cold air locked in the Arctic regions of the Northern Hemisphere, but this can become distorted and dip further south which is what much of the United States is experiencing.
But it’s a different story on the southern part of the hemisphere where high pressure is bringing in the heat from the equator, which is leading to extremely hot weather conditions. In the northern part of Argentina, the mercury level shot up to 50 degrees, the highest in the region in a century.
At least 10 people have died due to the extreme heat wave there. Some researchers say the Arctic air mass that the US is experiencing now could be related to global warming because it coincides with unusually high temperatures in other regions that are usually cold at this time of the year. Because we have got this very westerly jet stream blowing across the UK, it’s tending to draw a lot of warm air up from the Mediterranean and also from further afield such as the tropical Atlantic, so lots of warm air moving up across Spain into Italy and parts of southeastern Europe.
“The US National Weather Service,” says it expects this Arctic air mass to continue.