Storm Éowyn has unleashed strong and damaging winds over the British Isles, and particularly over Ireland and Scotland.

Air pressure at the centre of the storm plummeted 50 millibars in the 24 hours leading up to midnight on January 24. That’s more than twice what is required in the definition of “explosive cyclogenesis”, in other words, the development of a cyclonic (anticlockwise rotating) storm that is both rapid and severe – like a bomb going off. As a result, Éowyn can be termed a “bomb cyclone”.

It is not unusual for winter storms in this part of the world to reach bomb cyclone status. However, only very few in recent years have shown a rate of deepening pressure that is comparable to that of Storm Éowyn.