I flagged this not out of malice or anything but... lack of substance...<p>TLDR: Low pressure systems didn't block the cold air from retreating south<p>I was expecting a more scientific article, with science backed climate change analysis or something. The article seemed weak of substance by comparison.<p>> So why is this normally boiling state suddenly freezing over?<p>> According to the US National Weather Service (NWS), this is down to an "Arctic outbreak" that originated just above the US-Canada border, bringing a winter snow storm as well as plummeting temperatures.<p>> Cold air outbreaks such as these are normally kept in the Arctic by a series of low-pressure systems, the NWS said. However, this one moved through Canada and spilled out into the US last week.