With the anticipation that next week will have temperatures dropping well below zero degrees Fahrenheit, NNHS students may wonder why this phenomenon is occurring, and whether this will bring a cold day home from school.

What is causing this? It has to do with the polar vortex. The polar vortex is a large area of low pressure and cold air over the North and South pole, circulating air counter-clockwise. When something disrupts it, the vortex can shift or expand. Due to the large amount of warmer Pacific air Naperville had experienced, this shift in the polar vortex took full effect. Air masses are now being sent south from the North pole, forcing cold Arctic air across Canada and into the Midwest of the United States. However, it takes a long time to feel the effects of a shift in the polar vortex because it is so high in the atmosphere. In late December, the vortex actually broke into three swirling air masses.

The polar vortex itself doesn’t seem to be that new or irregular, and the National Weather Service notes similar outbreaks occurring in 1977, 1982, 1985 and 1989. In the winter of 2014-2015, Naperville experienced a prolonged period of cold following a rather warm beginning of the season. At that time, Naperville school districts closed schools because the weather temperatures dropped to a low of minus 6 degrees Fahrenheit on January 8, 2015. However, it is currently unclear whether students will have their cancelled-school-day wishes granted for this upcoming week.

In the meantime, bundle up, stay inside and be safe.