"倾盆大雨"的英语表达是 pouring rain或 torrential rain。例如：

1. It's raining cats and dogs all day, and now it's started to pour down with a torrential rain. [整天下起了倾盆大雨，现在开始倾盆大雨｡]

2. The forecast says there's a chance of torrential rain this afternoon. [天气预报说今天下午有可能有倾盆大雨｡]

3. Be careful on the roads, it's been raining so hard that there's a risk of flash floods from the torrential rain. [小心驾驶，下雨太大了，有可能会有倾盆大雨引发闪电洪水｡]