The message from the Exeter-based meteorologists is to enjoy whatever sunshine we have left on Sunday and to start with on Monday – but to be prepared for rain and wind.
But they insist it won’t be unusual weather for the time of year.
“Newspaper headlines suggesting that Ernesto itself is set to batter Britain aren’t accurate,” said deputy chief meteorologist Tony Wisson.
“The once powerful system itself will break down before it reaches us, but the warmth and moisture it once contained will become entrained within a mid-latitude frontal weather system.
“This will lead to unsettled conditions for the UK, especially across the north and west, with heavy rain and strong winds expected here.”
He added: “Although August is usually associated with fine and settled weather, wet and windy weather such as this aren’t uncommon, as seen in previous years.”
The Met Office says that although Monday will begin a bright day for many, a weather front working its way in from the west will bring rain, firstly, to northern and western parts of the UK.
By the end of the day most places across the UK can expect to see some rain.
Andy Page is a chief meteorologist with the Met Office. He said: “During Monday, the band of rain will gradually move east across the UK.”
Tuesday will see a temporary return to bright and breezy conditions with scattered showers, some of which will be heavy.
From Wednesday, weather conditions will turn unsettled once more.
A yellow rain warning is already in place for Wednesday and Thursday for parts of western Scotland.
During the warning period the heavy rain – which could see 75-100mm in places, and perhaps up to 150mm on some western-facing slopes – will be accompanied by strong southwesterly winds.
Gusts are expected to approach 50-60mph, which could bring some coastal impacts, especially during the high spring tide.
Hurricane Ernesto – which has brought impacts to Bermuda – has now been downgraded to a tropical storm but may briefly regain strength into Monday.
It will then weaken as it moves over the cooler waters of the north-west Atlantic during Tuesday.
The current forecast for the West Midlands is that Sunday will see a dry end to the day with some evening sunshine and staying dry overnight with prolonged clear periods.
It will be turning quite cool with temperatures dipping into single figures in the countryside with a few fog patches possible too. The minimum temperature is expected to be 8C.
It will be turning cloudier on Monday with showers by the evening.
Then heavier showers are possible by the evening.
The outlook for Tuesday to Thursday is for it being breezy with heavy showers possible for a time. It is set to be generally rather windy.