Shortly before 11 a.m. Thursday, Eric Fisher, the chief meteorologist for CBS News in Boston, tweeted: "#BOMBOGENESIS! Weather term loved by many, happening now south of Long Island. Falling 4mb/hr!"
“Genesis refers to the generating (of the storm), while bomb means it’s an explosive growth,” Bob Oravec, a National Weather Service forecaster told NBC News.
For the storm to form, a mass of cold air smashes up against an area of warm air, in this case the warm Gulf Stream waters. It's the sudden drop in pressure of the storm that makes it a bomb.