The Met Office issued its second red weather warning in less than two days covering a large area between south-west England and Wales.
BBC Weather forecaster Louise Lear advised commuters to heed calls for caution to limit "risks to life".
The BBC Weather presenter said: "The amber warnings are the ‘be prepared there will be some snow showers accompanied by strong gusty winds. There will be a blizzard at times. Be prepared for some disruption.’ But the red is ‘take action.’ There is a threat to life with the red.
"It’s the one down across Wales and south-west England. We’ve only seen two red snow warnings issued since 2013. The other one was yesterday. That just helps to emphasise how potentially severe this is. You really do need to take action."
BBCBBC Weather forecast: Louise Lear warned travellers to stay inside
Storm Emma is expected to hurtle into freezing