The figures for Wednesday night tell the story: 39mm of rain in Herstmonceux, East Sussex, 43mm at Wainfleet in Lincolnshire, both in the space of 24 hours. The Mid and West Wales Fire Brigade received 400 calls for help as some homes were 4ft deep in floodwater. South Wales police reported more than 80 calls within half-an-hour. In Swansea, Port Talbot, Neath and Briton Ferry, more than 20 fire appliances were called in to help pump out properties.
The west of the country always suffers worst. The annual rainfall in Cardiff and Swansea is approximately double that of Kew and Shoeburyness. Atlantic winds are responsible for about two-thirds of our total rainfall, and the west gets the worst of it for two reasons.
Most obviously, it hits them first. There is only a limited amount of moisture in the air, and any that rains on Wales is not available to rain further east. Second, any hills the air passes over will cause it to rise, cool, condense, and fall as rain. Then coming down the other side, it warms and increases its moisture-holding capacity. Less rain for London, though you wouldn't think it from the present conditions.Reuse content