The polar vortex that brought many US cities to a standstill was expected to end with a rapid thaw that experts say could be unprecedented. The bitter cold was caused by the mass of air known as the polar vortex drifting south from its usual position over the North Pole. Rockford saw a record low temperature of minus 35 C on Thursday. Milwaukee’s low was minus 31 C, and Minneapolis recorded minus 31 C. Wind chills were lower still. Masters, from Weather Underground, said the polar vortex was “rotating up into Canada” and not expected to return in the next couple of weeks.

Source: Philippine Daily Inquirer February 01, 2019 23:31 UTC