A BARRAGE of rain is set to strike the entire length of the UK - including Wales - on Wednesday, February 21, with flooding and major disruptions likely.

The wet weather will kick off just after midnight on Wednesday morning, with the Met Office issuing a yellow weather warning.

Heavy rain and coastal winds are set to dominate the entire Welsh landscape as the rain makes its way to the east of Wales - with the worst of it set to hit between 7am and 9.45am.

Up to 70mm of rain is set to fall on higher ground in Wales on Wednesday including the western parts of Caerphilly, Newport and parts of Monmouth. Rainfall will widely reach 15–25mm on lower ground.

Areas of lower ground are set to experience much less rain, up to 2mm per hour.

The whale-shaped storm will take shape around 9.30am on Wednesday, February 21. Planned road works on the M4 junction 32 to junction 33 have now been cancelled because of the yellow weather warning.

Hour-by-hour weather for Newport from midnight on Wednesday:

  • Midnight: 90 per cent chance of heavy rain, nine degrees;

  • 1am: 95 per cent chance of heavy rain, nine degrees;

  • 2am: 95 per cent chance of heavy rain, nine degrees;

  • 3am:  95 per cent chance of heavy rain, nine degrees; 

  • 4am:  95 per cent chance of heavy rain, nine degrees;

  • 5am:  95 per cent chance of heavy rain, nine degrees; 

  • 6am:  95 per cent chance of heavy rain, nine degrees; 

  • 7am:  95 per cent chance of heavy rain, nine degrees; 

  • 8am: 95 per cent chance of heavy rain, nine degrees;

  • 9am: 95 per cent chance of heavy rain, nine degrees;

  • 10am: 95 per cent chance of heavy rain, 10 degrees;

  • 11am: 95 per cent chance of heavy rain, 10 degrees.

  • 12pm: 90 per cent chance of heavy rain, 11 degrees;

  • 1pm: 60 per cent chance of heavy rain, 11 degrees;

  • 2pm: 10 per cent chance of light rain, 11 degrees;

  • 3pm:  10 per cent chance of light rain, 12 degrees; 

  • 4pm:  10 per cent chance of light rain, 11 degrees;

  • 5pm:  10 per cent chance of light rain, 11 degrees; 

  • 6pm:  10 per cent chance of light rain, 10 degrees; 

  • 7pm:  10 per cent chance of light rain, 10 degrees; 

  • 8pm: 10 per cent chance of light rain, 10 degrees;

  • 9pm: 10 per cent chance of light rain, 10 degrees;

  • 10pm: 10 per cent chance of light rain, 10 degrees;

  • 11pm: 50 per cent chance of heavy rain, 10 degrees.

Temperature and wind

The lowest temperature on Wednesday will be nine degrees, with highs of 12 degrees.

The Met Office said "coastal gales" will pay South Wales a visit along with the heavy rain coming in from the West.

Winds of up to 39mph will be observed in Newport around 9am, while Monmouthshire will experience gusts of up to 43mph.

Barry in the Vale of Glamorgan will also experience wind up to 40mph while winds in Penarth will reach up to 39mph.

Water levels and flooding

The Met Office predicts that flooding may cause delays on the road as chances of hydroplaning - when water builds between the wheels of a vehicle and the road surface, leading to loss of control - increase.

The rain clouds are set to travel from the west heading east, with the majority of rain to be cleared across areas of Gwent by 3pm on Wednesday.

Check in advance if your property could be at risk of flooding. If so, consider preparing a flood plan and an emergency flood kit.

Newport City Council is preparing a new flood risk management strategy, set to be released in the coming months.

Natural Resources Wales said "Local flooding from rivers and surface water is expected across much of Wales on Wednesday."

While flooding is possible, the risk is low according to Natural Resources Wales.

Travel – train and bus services

The worst of the weather seems to be between 7am and 9am on Wednesday morning, when the ‘whale-shape’ is at its peak.

This is where there may be more traffic on the roads moving slower than normal.

The rail operator, Transport for Wales, has issued a banner on its website for "adverse weather conditions across the network".

This means customers are advised to check their journey before travelling to see if the rain will lead to delayed or cancelled train journeys and routes.

Power cuts

Periods of adverse weather can sometimes lead to power cuts. 

Keep your eyes on The National Grid who will give regular updates if they get reports on power cuts in your area. Simply type in your postcode to find out.

If you are travelling anywhere, be careful in the rain.