Ex-hurricane Leslie will sweep past the UK towards mid-week feeding tonnes of tropical moisture into a string of low-pressure systems lined up in the Atlantic.
Energy released by the storm in her death throes will boost churning cyclonic weather systems unleashing a blast of widespread wet and windy weather.
Forecasting charts show two deep lows smashing into Britain, one towards the middle of the week ahead of another poised to strike just before next weekend.
The arrival of what’s left of storm Leslie will heap further misery on what is shaping up to be an already turbulent week of torrential downpours and gales.
Scotland faces almost a month’s rain through Sunday night with western England on alert for a roller-coaster approach to mid-autumn.
In a freak twist the storms will bring a flush of warm air into the country pushing temperatures back into the 20Cs through next week.
It will follow a chilly weekend with thermometers in parts set to drop below freezing bringing frosts and even snow to high ground.
Southern Britain will escape the worst of the weather over the next seven days with Scotland and the north in the firing line for the most brutal impact.
Met Office meteorologist Bonnie Diamond said: “Next week will see a nationwide split bring spells of heavy rain and strong winds to Scotland and parts of northwestern Britain.
“Low-pressure systems will bring some very unsettled weather to this region from the end of the weekend and there will be a fair amount of very heavy rain building from Sunday into the working week.
“These lows will affect mainly the northwestern half of the UK where winds could reach gale-force in exposed parts.
“Leslie is currently in the north Atlantic and will most likely remain there and is not expected to directly impact the weather in the UK.
“However, the presence of Leslie in the north Atlantic has helped to maintain a supply of tropical moisture in the mid-latitudes and this may serve to enhance the rainfall associated with next week’s low-pressure systems.”
UK weather forecast: Britain is braced for supercharged storms
Northern Britain will get a respite from the foul weather tomorrow when southern England will be on standby for wind and rain.
The mercury is forecast to nosedive by around 10C over the next 24 hours bringing a wintry feel across the nation.
Miss Diamond said: “On Saturday there will be a split across the country brought by a wavy weather front which will mean, while chilly, northern Britain will be drier and sunnier while across the south it will be wetter with some wind.
“It will feel much colder though across the country with temperatures in the south between 11C (;51.8F) and 15C (59F) while further north we are looking at around 10C (50F).
“Temperatures could dip below freezing overnight meaning there is going to be a risk of frost, and on Sunday a shift in terms of rainfall and more unsettled conditions will see better weather across the south.
“On Sunday night through until Tuesday we are expecting between 120mm and 15mm of rain across high ground in the far north, this is quite significant.
UK weather forecast: A month’s worth of rain could fall in some parts
“There will be a continued risk of strong winds, isolated gales and heavy rain through next week.”
Britains topsy-turvy weather will see the weekend chill chased off by a thrust of warm air poised to sweep the country after the weekend.
Stormy weather systems will arrive laden with tropical warmth pushing temperatures briefly around 15C above average.
Southern Britain could hit 24C (75.2F) by next weekend with eastern regions touching 22C (71.6F); Scotland and the far north will remain much cooler at around 14C (57.2F).
The soggy outlook has prompted bookies to slash the odds on this month hitting the record books for all the wrong reasons.
Ladbrokes is offering 7/2 on the wettest October ever with 6/4 on the weekend chill pushing overall temperatures to a record low.
Spokeswoman Jessica Bridge said: “The sun may currently be shining, but unfortunately it’s not going to last and Blighty needs to batten down the hatches and turn up the heating as the forecast changes.”
UK weather forecast: Temperatures could soar in the wake of chaotic UK weather
WeatherOnline forecaster Garry Nicholson warned parts of Britain will get a taste of the choppy weather ahead tomorrow.
He said: “Saturday will be a wet and cold day for central and southern England and Wales.
“High pressure will then build to give a brighter day on Sunday, but some early fog and frost is possible.
“It will become very warm during the week ahead as southerly winds develop.
“The remnants of Hurricane Leslie over the Atlantic will push spells of wet and windy weather into Ireland and the far west of Britain by midweek onward.”
Weathertrending’s John Hammond warned a bright start across southern Britain tomorrow will give way to an unsettled day.
He said: “We start Saturday with most of the wind across the north and west of England and Wales.
“East Anglia and the southeast might start off fine but the rain will arrive later on Saturday with things going downhill, things will turn wet and cold.
“It is going to feel particularly chilly with temperatures barely into double figures, meanwhile for Scotland and Northern Ireland it is not a bad day.”