What Exactly Are 'Monster Storms' And 'Bomb Cyclones'?

Nov 12, 2014
Originally published on November 12, 2014 3:17 pm
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Our ears perk of up whenever we hear an unfamiliar weather term, and over the weekend the cold weather in the upper Midwest revealed a new one - at least new to me.


UNIDENTIFIED WOMAN: Talking about the wild weather, a bomb cyclone - yes, that is an actual weather term - is triggering an arctic blast.


UNIDENTIFIED WOMAN #2: It's a bomb cycle.

SIEGEL: This bomb cyclone happened when Super Typhoon Nuri in the Northern Pacific collided with cold air over Alaska, and we learned that this term has been around for decades...

JASON SAMENOW: ...Referring to a mid and high-latitude storm which explosively deepens or intensifies.

SIEGEL: Jason Samenow is weather editor for The Washington Post and chief meteorologist Capital Weather Gang. Samenow says a bomb cyclone means that air pressure has fallen very fast, dropping one millibar every hour for 24 hours - the lower the pressure, the stronger the storm.

SAMENOW: And in the case of the storm in the North Pacific in the Bering Sea, its pressure dropped almost 60 millibars in 24 hours. So it more than doubled the rate of what we consider a meteorological bomb.

SIEGEL: He says such bombs can happen anywhere - even the Tropics.

SAMENOW: We see this happen all the time, by the way, so this - sometimes we'll refer to it as bombogenesis when this happens.

SIEGEL: Bombogenesis?

SAMENOW: That's right. That's another term we sometimes use.

SIEGEL: By the way, Jason Samenow says not all rare meteorological terms mean trouble.

SAMENOW: There's another one which I saw referred to yesterday - the omega ridge which is a huge ridge of high pressure which blocks weather systems from moving into a particular area which means you stay warm and you stay dry.

SIEGEL: I wouldn't mind an omega ridge in mid-January. It's also a great name for a country band.

(MUSIC) Transcript provided by NPR, Copyright NPR.