Rainfall can revive them in a matter of hours.

降雨可以在几小时内使它们恢复生机。

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Observed rainfall in the last 1 hour is over 10 mm and the observed rainfall in the last 12 hours is over 100 mm.

在过去一小时实际降雨量超过10毫米，在过去12小时实际降雨量超过100毫米。

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Observed rainfall in the last 6 hours is over 80 mm.

在过去 6 小时实际降雨量超过 80 毫米。

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Last June heavy flooding hit Aberystwyth and nearby villages with a month's rainfall in 24 hours.

BBC: Flooding: Extra ?10m to protect communities in Wales

More than two weeks' worth of rainfall fell over two hours on the evening of Wednesday 4 August, causing extensive flooding to properties.

BBC: Goole flooding caused by 'exceptional downpour'

"This was very, very intense rainfall, with five inches in 24 hours in some areas, even some of the best defences are going to be overwhelmed, " he added.

BBC: NEWS | UK | Water runs out in flood-hit areas