Why meteorologists are comparing Storm Eowyn to a bomb

Storm Eowyn 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 r