(NewsNation) — The National Weather Service confirmed that a polar vortex is not heading to Indiana, despite a viral image on social media that sparked concern, the IndyStar reported.

The term polar vortex has been coined a “rising star” by the Polar Vortex Blog, which notes that although it’s made headlines in recent years, it’s often “misunderstood or misrepresented.”

The blog’s purpose is “monitoring and forecasting the stratospheric polar vortexes and how they do and don’t—mostly don’t!*—affect extreme winter weather and seasonal climate.”

What is a Polar Vortex?

A polar vortex is not actually a synonym for “cold snap,” according to the blog.

Rather, it’s “a well-known feature of Earth’s atmosphere that describes the high-altitude winds that blow around the pole every winter, miles above us in a region called the stratosphere.”

A polar vortex forms in the winter hemisphere where Earth’s pole is pointed away from the sun, per the blog.

The polar “stratosphere enters darkness and becomes cold relative to the tropical stratosphere. The temperature contrast makes for strong winds in the stratosphere that blow from west to east.”

This wintertime stratospheric wind is what we call the “Arctic polar vortex.”