Weather Bomb
I see the BBC are talking about a weather bomb as being a drop of 24 hPa in 24 hours. In respect of the low pressure system about to hit NW Scotland they are expecting a weather bomb of 50 hPa and a minimum pressure of 930 hPa.
In my day we only had settings on our altimeters down to 950 hPa and I remember the initial confusion back in the early 80's amongst the helicopter operators out of ABZ when one day the QNH for altimeter settings on the track system dropped well below 950. Does the more modern glass cockpit kit cope with pressure down to 930?