The storm is expected to develop south west of Britain tomorrow and reach the south coast of England on Sunday night and into Monday, bringing exceptionally strong winds.
The storm could develop winds hitting 12 on the Beaufort Scale. This is the strength of a hurricane.
With gusts of up to 90mph and up to 30mm of rain forecast the RAC has warned motorists against all but essential travel in torrential rain and floods.
The public has also been warned to expect the possibility of power cuts, trees blocking roads and transport disruption.
Met Office spokesman Dan Williams said today that forecasters had extended their amber warning for strong winds further north. London, East Anglia and Bristol are all now expected to be hit by heavy winds and rain.
Flashback to 1987, when gales forced this Sealink ferry on to the beach on the south coast of England near Folkestone Dan Williams explained why the storm was potentially so significant: "These storms usually develop much further out in the Atlantic, so when they come over the UK they are in the declining phase and decrease in strength.
"What we're seeing with this one is that it developed very rapidly much closer to the UK."
"There is a system of low pressure developing across the Atlantic but it doesn't start to deepen until it's quite close to the UK."
"It then deepens very rapidly. It is still maintaining or gaining strength as it moves across the country."
"That's why this has the potential to be quite a significant storm. Because it will be at its most vigorous stage of development while it goes over the UK."
"The most similar one in terms of track and strength would be the Burns Day storm of 25th January 1990."
A wrecked car on a London street hit by falling masonry during the 1987 storm Eddy Carroll, chief forecaster at the Met Office, added: "This storm doesn't exist at the moment, but our forecasts models predict it is likely to develop in the west Atlantic on Saturday.
"Then it's likely to rapidly intensify just west of the UK late on Sunday before tracking across England and Wales early on Monday.
"There is still a chance this storm may take a more southerly track and miss the UK, bringing impacts elsewhere in northern Europe, but people should be aware there is a risk of severe weather and significant disruption.
"With that in mind, people should keep up to date with and act on the advice in our forecasts and warnings as the situation develops."
There is still no guarantee that the storm will actually hit the UK. According to the Met Office, Atlantic storms of this type usually develop much further to the west of Britain and lose much of their strength before they reach the UK.
A policeman surveys the damage on a London road caused by the 1987 storm Met Office senior forecaster Helen Chivers warned that winds could get up to 90mph and said the storm could be exceptional: "This is not a storm you see every winter."
"The storm of 1987 is one, and the Burns day storm in January 1990 is another."
"'It is important to realise the track of this low is at the moment not certain. In this type of situation it is really, really important that people keep up to date with the most up to date warnings."
Forecasters said this storm was unusual as it has developed much closer to UK and could potentially be tracking across the country while still in its most powerful phase. A strong jet stream and warm air close to the UK are both contributing to the development and strength of the storm, the Met Office said.
Public in the affected area "should be prepared for the risk of falling trees as well as damage to buildings and other structures" caused by strong winds, forecasters said.
The Met Office has issued severe weather warnings for wind and rain for all of England and Wales for Monday and warned people to be prepared.
"This is a developing situation so people should really stay up to date with the latest information and warnings and really keep in mind that there could be a significant event in England and Wales and really factor that into your plans."
"Because there is a risk of significant disruption. People should heed the advice of the road safety organisations and only travel if it is absolutely necessary. There's a possibility of trees blocking roads, power cuts, transport disruption," Dan Williams said.
The aftermath of the 1987 "Great Storm" The Great Storm of 1987
Last week saw the 26th anniversary of one of the worst storms in British history.
The Great Storm, as it is often called, hit Britain in the early hours of 16 October 1987. The storm was the worst to hit Britain in over three hundred years and claimed 18 lives, caused £1.5bn worth of damage and brought down an estimated 15 million trees.
At one point the winds reached speeds of 120mph. The National Grid sustained heavy damage leaving thousands without power.
At the time forecasters were criticised for failing to predict the storm. In particular BBC meteorologist Michael Fish drew opprobrium after saying in his broadcast: "Earlier on today, apparently, a woman rang the BBC and said she heard there was a hurricane on the way; well, if you're watching, don't worry, there isn't, but having said that, actually, the weather will become very windy, but most of the strong winds, incidentally, will be down over Spain and across into France."