During the days leading up to January 3, millions of Americans along the East Coast braced for winter storm Grayson, or as it was more notoriously called, the “bomb cyclone.” Food was stockpiled, snow clothes were readied, and shovels were on hand, all in anticipation for the ominously named winter storm. Grayson was the biggest snow storm this winter, but what does the term “bomb cyclone” really mean, how large was the impact area, and how much snow did the rest of the east coast get?

First of all, the term bomb cyclone does not refer to the size of the storm or even the amount of snowfall. A bomb cyclone, or explosive cyclogenesis, refers to how the storm gains power. According to Earth Science Teacher Chris Pipia, “Air pressure has to drop 24 millibars in 24 hours, which really affects the winds and the amount of snowfall.” It is that event, the rapid drop of pressure, that gives the storm its name, according to Popular Science. When this happens, the storm gains power and is officially designated a bomb cyclone. In the case of Grayson, this happened in freezing weather while it was over the ocean, which caused the moisture from the ocean to be blown into the atmosphere where it condensed and froze into a snowstorm with similar wind speeds and pressure to “Super-storm” Sandy. Bomb cyclones are most common in the winter, as was the case with Grayson, so it was surprisingly not an unusual event, scientifically speaking.

Grayson covered the entire Eastern seaboard in snow, with wind gusts up to 60 mph, according to The Weather Channel (weather.com). Grayson even brought the rare sight of snow to parts of Florida. The Weather Channel reported as high as 22 inches of snow in Maine. They also reported 16 inches in parts of New York with a snowfall rate of two to three inches an hour. This snowfall was caused by the explosive cyclogenesis or “bombing” that Grayson went through before making landfall. The storm also caused significant coastal flooding in places including Boston. Bomb cyclone Grayson kept thousands of kids out of school this January, slowed the commutes of millions of workers, and left the ground with an average snow level of one foot.

Winter storm Riley, which took place the weekend of Mar. 2, brought a torrential downpour of rain, wind speeds over 45 mph, power outages, and, unfortunately, nine deaths, according to The Weather Channel, but what people may not know is that Riley underwent “bombogenesis” (a colloquial term for explosive cyclogenesis) to intensify into a bomb cyclone just like Grayson. Luckily, the temperature was warm enough to prevent heavy snowfall, but the bomb cyclone still caused catastrophic flooding and wind damage.

There are many important things that people should do to prepare for future storms. In relation to a question about preparation, Pipia said, “I would prepare for this type of storm similarly as for other storms.  You need to have non-perishable food and water (probably for three days if possible), a flashlight, and battery-operated radio in case of a power failure. If a storm is associated with cold temperatures, layer clothing if you are going out.  Maybe, be prepared so water pipes don’t freeze, and of course,  have a snow shovel.”

With climate change affecting weather patterns, it is important as ever that people are ready to stay safe in whatever weather conditions arise.