Met Office issues 21-hour rain warning as millions of Brits face floods and power cuts

The Met Office has put out a weather warning affecting millions of Brits as downpours are set to hit the nation.

The yellow warning covers a huge swathe of the country, from the south of the country and extending as far as Manchester. It says from 9pm Saturday to 6pm on Sunday areas of heavy and thundery rain are forecast across the region.

Some areas could endure up to 100mm of rain which will extend north. There is a chance of flooding and power cuts for some places in the areas. The Met Office warning reads: "Whilst there remains some uncertainty with exact details, areas of heavy and at times thundery rain are expected to spread north, then west, across England and Wales from this evening and overnight.

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"These areas of heavy rain may become more persistent across western areas during Sunday daytime whilst slow-moving heavy showers and thunderstorms are likely to develop further east. Rainfall amounts will vary considerably across the warning area with some locations seeing less than 10 mm of rainfall whilst others see 40-60 mm of rain.

"There is a lower chance a few spots within the warning area could see 80-100 mm of rain by the end of Sunday which may fall in a fairly small period of time. These higher totals are slightly more probable in the southern half of the warning area.

"Given this region has also seen a lot of rain since Thursday, impacts may be more likely than would normally be expected for the time of year here."

A flood warning is in place in parts of the UK as the weather office states heavier lashings of rain are on their way. The "heavy and thundery rain" is set to arrive today on the south coast and move northwards overnight. It is expected to affect central and southern England and Wales.

The Environment Agency has two active flood alerts issued in south-west England at time of reporting, with the Lower Avon river flagged as a possible source of trouble. Most in southern and central England are at a low risk of flooding, with a similarly low risk to property impact and travel disruption.

Regions and local authorities affected by the yellow warning

East Midlands

• Derby

• Derbyshire

• Leicester

• Leicestershire

• Lincolnshire

• Northamptonshire

• Nottingham

• Nottinghamshire

• Rutland

East of England

• Bedford

• Cambridgeshire

• Central Bedfordshire

• Essex

• Hertfordshire

• Luton

• Norfolk

• Peterborough

• Southend-on-Sea

• Suffolk

• Thurrock

London & South East England

• Bracknell Forest

• Brighton and Hove

• Buckinghamshire

• East Sussex

• Greater London

• Hampshire

• Isle of Wight

• Kent

• Medway

• Milton Keynes

• Oxfordshire

• Portsmouth

• Reading

• Slough

• Southampton

• Surrey

• West Berkshire

• West Sussex

• Windsor and Maidenhead

• Wokingham

South West England

• Bath and North East Somerset

• Bournemouth Christchurch and Poole

• Bristol

• Cornwall

• Devon

• Dorset

• Gloucestershire

• North Somerset

• Plymouth

• Somerset

• South Gloucestershire

• Swindon

• Torbay

• Wiltshire

Wales

• Blaenau Gwent

• Bridgend

• Caerphilly

• Cardiff

• Carmarthenshire

• Ceredigion

• Merthyr Tydfil

• Monmouthshire

• Neath Port Talbot

• Newport

• Pembrokeshire

• Powys

• Rhondda Cynon Taf

• Swansea

• Torfaen

• Vale of Glamorgan

West Midlands

• Herefordshire

• Shropshire

• Staffordshire

• Stoke-on-Trent

• Telford and Wrekin

• Warwickshire

• West Midlands Conurbation

• Worcestershire

Yorkshire & Humber

• North East Lincolnshire

• North Lincolnshire

• South Yorkshire