Arctic polar vortex impacting world weather

A blast of Arctic air from the polar vortex brought dangerous, bone-chilling cold to a wide swathe to northern hemisphere. The US Midwest was the hardest-hit region, as temperatures plunged below -18 deg C. By nightfall, the mercury was hovering at -18 deg C in Chicago, -14 deg C in Detroit and -29 deg C in Minneapolis. Northern India is another region which is highly affected by this phenomena.

In India, Churu, Rajasthan has seen temperature dropping to -1.1 degree. Pahalgam saw temperature of -13.7 . Keylong was recorded at -16.2 which is coldest in India. Entire J&K, Himachal and Uttarakhand was below 1 degree and Delhi saw temperatures about around 4-5 degree.

Western disturbances (WDs) are pulses of low pressure winds that travel westwards from in and around Mediterranean  region, bringing cold, moist winds that either hit Himalayas or blow over to the north.