New weather maps from WXCHARTS indicate a 700-mile wall of rain will hit the UK on August 4, affecting 54 counties from Wick in northern Scotland to Devon in southwest England. The downpours are forecast around midday as changeable conditions move eastwards.
Some of the worst-affected areas in England include Lancashire and North Yorkshire, which could see up to 7.5mm per hour of rain.
Met Office forecast for August 1-10
The Met Office forecast for August 1 to 10 states: "Mostly dry away from the north and northwest initially, where scattered showers are expected."
"There is a small chance that some other western parts could see some rain by the end of the weekend. Temperatures ranging from around average in the NW to warm in the southeast, perhaps becoming very warm in the southeast through the weekend."
"It will probably become more changeable thereafter, with potential for an area of low pressure to move close to or across the UK early in August."
"This could bring spells of heavy rain and perhaps some strong winds for a time. It may become more settled again towards the end of the first week of August."
Counties forecast to see rain
The following counties are expected to be affected: Aberdeenshire, Angus, Argyll, Ayrshire, Banffshire, Buteshire, Caithness, Clackmannanshire, Cromartyshire, Dumfriesshire, Dunbartonshire, East Lothian, Fife, Inverness-shire, Kincardineshire, Kinross-shire, Kirkcudbrightshire, Lanarkshire, Midlothian, Moray, Nairnshire, Orkney, Peeblesshire, Perthshire, Renfrewshire, Ross-shire, Roxburghshire, Selkirkshire, Shetland, Stirlingshire, Sutherland, West Lothian, Devon, Somerset, Bristol, Gloucestershire, Herefordshire, Shropshire, Cheshire, Merseyside, Lancashire, Cumbria, Hampshire, Berkshire, Oxfordshire, Warwickshire, Worcestershire, West Midlands, Staffordshire, Greater Manchester, Derbyshire, North Yorkshire, South Yorkshire, West Yorkshire.
