Well at 4.30 pm on Tuesday we had the most violent rain/hail squall I have ever witnessed in the UK. Only slight thunder but I recorded 78mm/hr and I suspect it was even more with bounce out. Temperature plummeted and the wind swirled and gusted. The road became like white water rapids and there was a thick layer of ice. The hail here was up to 1cm diameter but I've seen pictures of larger. Well drained patio was under a few inches of water. Elsewhere there were flash floods. Some local homes in the foothills of Langdon Hills had a foot of water in their lounge. I saw one house where a ditch had burst its banks and the water was cascading through their side garage in a torrent into the deeply flooded road. Fire brigade out in force and the scenes were just like those I've seen on the television when it's happened in the North and West. The only time I've seen something comparable was one September in Sydney. I think it must have been relatively localised because I had expected it to be on major News Channels but it barely made the local news. Perhaps it was because it was only a 20 minute event.
I recorded 14mm in my small rain gauge but suspect it wouldn't have kept up and may have been twice that. If I can figure it out editing it I'll try and upload a short video.