Downpour n. a heavy fall of rain

The weather has been rather unusual recently. It's summertime and we're having great dollops of lovely warm sunshine, blue skies and balmy breezes.

Just to compensate , however, we've also had quite a few enormous rain storms; fearsome deluges, occasionally with hailstones, accompanied by salvoes of thunder and lightning. This is much more like the summer weather I'm used to.

As I was driving to work on Saturday for a night shift, it became clear that there'd been some serious rain at Jodrell Bank, even though three miles earlier it had remained stubbornly dry. The driveway from the main entrance was completely flooded in two places so when I got to the Control Room I thought I'd better warn my colleague to take care when he left at midnight.
He wasn't at all surprised that the drive was awash,
"I've never seen so much rain fall in such a short space of time." he said
"Have a look at the rain chart..."

We take meteorology readings every day and although we no longer supply data to The Meteorological Office, the information is used by our astronomers.
We have a Rain Gauge to record the amount of rainfall every day and we also have a Rainfall Chart Recorder that shows when and how quickly the rain falls. That's the handsome, brass instrument in a glass box in the picture.

When I looked at the chart I could see what he meant.

When the Rain Gauge was read the following morning, the total rainfall for the day was 35mm and, as you can see from the picture of the chart, most of it fell in about fifteen minutes. Quite extraordinary.

It's a good job it didn't rain like that at Glastonbury...