What were the causes of your flash flooding case study.

1)low pressure system brought warm rising air from Atlantic ocean, cooled as it rose forming thuderstorms and intense rainfall. This also meant 75mm rain (monthly amount) fell in 2 hours 2)Previous rain wet the land so it couldnt absorb rain leading to surface run off 3)Bostcastle is in a steep-side valley in the confluence of 3 rivers. Steep valley side means surface ran off to river channels quickly so 2 billion litres of water funneled down river into boscastle 4)Cars and trees trapped in the arch of an old bridge forming a dam