After tropical winds push temperatures into the high teens, the skies will turn “very lively”, forecasters warn.
A deepening region of low pressure firing up in the Atlantic will spin towards Britain on the tail of a powerful jet stream.
A barrage of storm systems churning off the west coast will hurl bands of persistent wind and rain towards the UK.
Met Office meteorologist Alex Deakin said: “There is going to be something very lively, possibly, as we go into next week.
“There are some quite potent areas of low pressure quite close to the UK, and these low-pressure systems out in the Atlantic will be bumping up towards the UK.
“All the ingredients are there as the active jet steam picks up, and these low-pressure systems could turn into volatile systems.
“A few computer models suggest something very lively just to the west of the UK for the early to mid-part of next week, and that is why we need to keep a close eye.”
“We will have a lot of mist and low cloud around, but it is going to feel pretty mild, and most places will be dry. There could be some drizzly conditions particularly over the hills.”
As the weather spices up after the weekend, parts of the country are on alert for thunder and hail.
Unsettled weather fronts will edge into Britain bringing the first downpours later on Sunday, forecasters warn.
Jim Dale, meteorologist for British Weather Services, said: “The weekend will be largely mild and settled and then fronts start to come in on Sunday and it all changes into the working week.
“It is certainly going to be disturbed, and it will start turning interesting possibly from Monday and into Tuesday and Wednesday as low pressure moves in from the west relatively close to the UK.
“There might be some thunder around during the week with some hail activity, and windy in parts. We are looking at everything really but the kitchen sink.”
Despite the change in weather, bookies are still hedging their bets on this month turning out warmer than average.
Coral is offering 6-4 from 5-1 on the hottest November ever as thermometers continue to rise around 10C above normal putting the 22.4C record under threat.
Spokesman John Hill said: “Mild temperatures look set to continue over the weekend, and if the unseasonably warm weather continues, we could be set for the hottest November day in history this year.”
Weathertrending meteorologist John Hammond said: “Our plume of relative November warmth will linger through the weekend, but through the week ahead it will be subject to a squeeze, both from the east and the west.
“Meanwhile, to our east, a developing area of high pressure will be trying to push much colder air in from Scandinavia.
“The upshot may well be that a series of fronts stall across the UK, bringing plentiful wet weather.”