Cumulus Support

Yesterday my vp2 recorded 9.0mm in an hour, and a respectable rain rate of 149.6mm/hour. I checked the 3 local vp2s, two recorded less than 3.0mm in an hour but the third situated 7 miles away in Harpenden, Hertfordshire recorded 30.0mm; but that wasn’t the real surprise. It recorded an astonishing rain rate of 1080mm/hour!!!

Colin

It sounds like a spider was swinging on the bucket, or the whole unit was being shaken by the wind, as it is hard to imagine a rate of 1080mm/hr. Do you know how reliable it might be?
The highest I've seen here in a torrential downpour was 345mm/hr for a very brief period and rain >3X that heavy would just be insane!

I recently recorded 10.29"/hr in a very heavy downpour. That equates to 261mm/hr. That beats 9.76"/hr back in July 2009.

To have a rain rate almost 4 times as heavy seems inconceivable in the UK. But without being there I wouldn't know what it was like.

Bear in mind that the VP2 measures rain rate by the time between successive tips, and a small amount of rain falling very quickly gives a high rain rate figure. A rate of 1080 mm/hr is equivalent to two 0.2mm tips two-thirds of a second apart. I don't know how feasible that is, but the VP2 spec says the maximum is 2438 mm/hr, which is two tips a third of a second apart (approx), so presumably the gauge is capable of it.