Storm Debi: New flood warning is announced for tomorrow as astonishing pictures show prehistoric mound now has its own moat thanks to the rain

The Met Office issued a new yellow warning for heavy rain across southern parts of England today as astonishing pictures showed how a prehistoric mound developed its own moat due to the downpour. 

The stunning image shows the 4,000 year old earth mound, which towers over the Wiltshire countryside, with a horse-shoe shaped moat that has formed around its base, after Storm Debi battered parts of the UK with heavy rain and 80mph winds.

The mound, known as Silbury Hill - one of the most mysterious and striking structures in Britain - lies close to the stone circles of Avebury and a few miles from Stonehenge.

The ground surrounding the chalk mound, which roughly compares in height and size to the Egyptian pyramids, is believed to have become soft and saturated following the heavy rain, carving a moat around it. 

English Heritage's senior properties curator Win Scutt, told the BBC: 'The lake that forms seasonally around Silbury Hill is not a problem and drains away naturally.' 

The Met Office has warned heavy rain rain is expected to move across parts southern parts of England tomorrow.

The forecaster also warns that strong gusts reaching 50mph, with a small chance of gusts reaching 60 mph for the Isles of Scilly and west of Cornwall.

Regions that believed to be affected by the adverse weather include London, Brighton, Kent, Portsmouth, the Isle of Wight, Bath, Bristol, Somerset and large parts of Wales. 

The environmental agency has issued 12 flood warnings for areas near the River Ouse in north Yorkshire, River Derwent, Derbyshire and Washford River which flows through somerset. 

The yellow warning for rain issued by forecaster are in place from midnight and will end at 6pm tomorrow, with disruptions to travel as drivers are warned spray and flooding on roads is likely to make journey times longer, with bus and train services also affected.

A further 112 flood alerts for areas with possible flooding, which include the River Thames where river levels are expected to remain high over the next few days.

The forecaster also warns that the flooding of homes and businesses is possible, and that there may be some interruption to power supplies tomorrow. 

Brits will be bracing for stormy weather over the next few days as a jet stream coming in from the Atlantic, affecting mainly southern parts of the UK.

Rain and strong winds are expected to reach southwest England this evening and spreading northeast overnight, reaching South Wales and London by dawn, meaning a chilly start to the day tomorrow. 

Blustery gusts are expected tomorrow, with much of the heavy rain affecting south Wales, central and southern England, with more pleasant sunnier spells elsewhere.

The rain is expected to ease up by Friday, with dry and brighter conditions before turning wet and windy again on Saturday, and some showers lingering into Sunday.

Yesterday, Storm Debi unleashes its fury on Britain, sending Christmas trees toppling in 70mph gusts and sparking flood warnings.

The fourth named storm of the season so far has caused travel chaos after gale force winds brought down trees at several locations, damaging overhead lines.

Storm Debi first hit Northern Ireland and the Republic of Ireland before lashing Wales and moving eastwards into the North Sea.