What is a ‘bomb cyclone?’

(NewsNation Now) — You’ve no doubt heard by now that the force behind this weekend’s incredibly frigid temperatures (and the bursts of record-shattering chill in recent years) is a “bomb cyclone,” but what is that?

Think of a bomb cyclone, also known as an incident of explosive cyclogenesis, as a winter hurricane. It packs the rotation of a hurricane and winds nearly as strong, but it forms in the far north, meaning that its counter-clockwise flow “throws” incredibly cold air from the polar regions down into areas like the Midwest and Northeast that don’t normally see things that cold.

A storm experiences “bombogenesis,” becomes a bomb cyclone, when its internal pressure drops by 24 millibars in 24 hours, a process known as “bombing out.” If you’ve paid attention during hurricane season, you know one of the main indicators of how strong a hurricane is becoming is the barometric pressure and how much it’s dropped in a 24-hour period. A drop of 24 millibars is precipitous, and means to anyone looking that it’s time to get inside, fire up the fireplace and get out the board games.

How cold, you ask? Chicago is looking at wind chills of -25 degrees Fahrenheit over the weekend. That means exposed skin can experience frostbite very quickly, and bundling up won’t help much, either. Winds will top 60 mph in many areas, not only driving wind chill but also ensuring that any snow that’s falling will whip into blizzard-like conditions. Even an inch of snow can look like a blizzard with that much wind driving it.

Just like a hurricane, the bomb cyclone will track from west to east, but its exact track can vary based on other influences. In Charlotte, North Carolina, for example, forecasts are wobbling anywhere between 3-4 inches of snow, ice, rain or a mix of all three depending on how the storm interacts with the Blue Ridge Mountains to the west.

The best advice for those in the Upper Midwest and Northeast is to stay indoors as much as possible this weekend and stay tuned to your local weather information sources for updates. If you don’t absolutely have to be out and around, don’t be. It’s safer for you and for the emergency personnel who might have to come find you if you run into trouble.