That the daily rainfall work reveals another (weather) world is, I think, by now apparent to interested readers. Certainly, for me, from very early in the daily rainfall entry work, this new world came more and more into ranges of focus. The next feature was that one very wet day.
The Temperate rainfall zone does, occasionally, refer to an extreme downpour as a “cloud burst”, but other than being a lot of rain very quickly, definition disappears into the distance.
600 mm isohyets were used as the benchmark for this feature: falls of 60 mm in one day were described as being a Wet Day.

Usually, in the sub-Tropical climate zone, such a fall implies a thunderstorm gone wild. They would be scarce in our climate range. Such daily measures are unknown in the Temperate/Winter rainfall belts. Some couple of years back, a town in the Pomorze province of Poland recorded an August storm of 26 mm. This broke all kinds of records, local and regional. Here, we would say thank you and look for a follow-up. In the Tropical, or Equatorial, rainfall belt, the query would be that such an amount would be recorded among a group of hours.
The standard approach where extreme events, rainfall among others, are concerned is to note these with some interest, but to discard them from the practical records because they are beyond a certain percentage of the normal. But our climate is not “normal”. Sub-Tropical or Arid Climate rainfalls are identified by the likelihood of occasional heavy downpours (cloudbursts), so when the do occur, such occasions need to be identified and incorporated into the record for that one (or any) station.
Apart from trying to appear maverick, it should be realized that such falls, as irregular as they usually are, are part-and-parcel of our climate and play a, presumably, vital role where the ecology and the environment are concerned.
The penetration and run-off value of a heavy downpour may be difficult to evaluate, but the reality of flowing streams and, eventually, greening vegetation cannot be ignored.
But what makes a “cloudburst”? Our rainfall weather is very reliant on thunderstorm development. Usually, the resultant cumulonimbus cloud (cumuli being towering growth, nimbus being rain) begins precipitation of its considerable moisture surplus before anything dramatic can happen. Depending on atmospheric circumstances, the resultant shower varies from a few drops into a fall of Productive (10 mm or more) or Substantial (25 mm or more) measure. While such storms are referred to as being local or isolated, they can also be scattered or widespread. Dedicated surface observation, backed up by a satellite image reveals a level of atmospheric cohesion enabling these showers to develop.