bomb cyclone US
People on the US east coast dealing with a winter storm that is set to deliver plunging temperatures, strong winds, blizzards and coastal flooding have been provided a suitably stark term for the experience - "bomb cyclone".

The storm, currently forming off the coast of Florida before it's expected sweep up the entire eastern seaboard, has been described as a sort of winter hurricane or bomb cyclone due to its rapid formation and heavy impact.

"It's definitely the polar vortex of this year," said Gregg Gallina, a meteorologist at the National Weather Service, in reference to the frigid spell that enveloped much of North America in 2013 and 2014.

"The term bomb cyclone certainly catches the eye. I understand that with the sensitivity of the politics words like bomb take on a different meaning. This storm will be dangerous but people shouldn't panic. Actual explosives are more of a panic."

Gallina said that while the term explosive cyclogenesis was "probably a better option" when describing the phenomenon behind a bomb cyclone, mentions of bombs and explosive impacts have been common for decades among meteorologists.

The National Oceanic and Atmospheric Administration defines the "bomb" phenomenon as being a mid-latitude cyclone that rapidly intensifies as cold air collides with warm air, typically over warmer ocean waters. This process causes a steep drop in atmospheric pressure of at least 24 millibars over 24 hours.

Noaa said this could be called a "bombogenesis" and it is not unheard of - it occurs about once a year off the US east coast.

"The 'bomb' is in reference to the speed of the change; the real significant difference will be the increase in wind that is whipped up," said Gallina. "There will be a huge impact from the wind and coastal flooding. It will be brutally cold. We really hope people will hunker down and stay indoors."

At least 11 people have died due to the low temperatures that have gripped much of the eastern US since Christmas. Southern states such as Georgia, South Carolina and Florida have experienced unusually cold weather, with some towns getting their first settled snowfall in decades. Further damage to life and property is expected from the coming storm, with atmospheric pressure predicted to drop to similar levels to those that helped form Hurricane Sandy in 2012.

Winds and flooding are expected to batter coastal areas, with major cities such as New York and Boston getting at least 4in of snow by late Thursday. Parts of Maine and Massachusetts are forecast to receive about 1ft (30cm) of snow, with the winds causing dangerous blizzard conditions in places.

Much like during the polar vortex, the American public is being introduced to weather terms often used by meteorologists but not widely known until they directly affect a large number of people. Then there are the terms coined largely by the media, such as "snowmageddon" or "thundersnow" (which is when snow rather than rain falls during a thunderstorm).

"As long as people understand what bomb means in this context, it's helpful for the speed of preparation for the storm," said Kelly Lombardo, an atmospheric scientist at the University of Connecticut. "Something like snowmageddon I have more mixed feelings about. It's like: are you pushing it too far and causing panic? But with bombs there's actually a basis for it in scientific literature."