Having rapidly deepened over the last 24 hours, the storm has undergone a process called explosive cyclogenisis, forcing violent winds from the system known as ‘bombs’.
Travel disruption, damage and flying debris were on the menu from 6am, when she officially set in, the Met Office warned.
By lunchtime, all west coast services out of London Euston station had been cancelled and travellers were asked to avoid the station if possible.
An 87mph gust was recorded at Mace Head on the Galway coast in the Republic of Ireland in the early hours as Doris made its way east.
Britain is expected to be battered with winds of up to 80mph at the storm’s peak and Highways England has issued a weather alert on major roads.
Amber warnings predict strong winds and heavy rain in parts of north Wales, the Midlands, and the East and North West, while winds as fast as 60mph are also expected to batter southern England.
Weather warnings have been upgraded to amber across Scotland’s central belt, the Borders, Dumfries and Galloway, Tayside and Fife.
“We have got a fairly active area of low pressure coming in from the Atlantic,” said Met Office forecaster Emma Sharples.
“It is strengthening as it moves eastwards to the UK.”
It’ll be a flying visit however, with the worst of the weather gone by Thursday evening.
AA spokesman John Snowling said: “The unpleasant combination of torrential rain, severe gales and heavy snow will create some very poor driving conditions, with the potential for roads to be affected by black ice, debris or standing water.
“Wind can also bring down tree branches, blow you off course or blow other vehicles into your path.
Anyone affected by power cuts during the storm is encouraged to dial 105 for further information.
Storm Doris’s appearance contrasts with Monday’s temperatures, where visitors to Kew Gardens, west London, enjoyed the warmest day of the winter so far, at 18.3C (64.9F).
Parts of London and the South had temperatures warmer than Ibiza, southern Spain and Menorca.