On Aug 18, 8:18*pm, Stephen Burt wrote:
My checkgauge total 0900-1800z today was 66.2 mm.

(Standard and well-exposed climatological station site - MetO and EA
rainfall site 270162, last inspected in 2010.)

Total from my two TBRs 66.0 mm and 60.2 mm. My Davis VP2 AWS TBR
managed only 38.2 mm: not sure why the big difference, but it
certainly shows the necessity for a deep-funnel checkgauge to get an
accurate standard reading in torrential rainfall.

This is not only my ‘personal’ highest 09-09 fall in 40 years
observations, but the highest 09-09 fall on my local unbroken daily
records back to 1910; the previous highest was 58.4 mm in a
thunderstorm on 6 August 1982.

There have been higher falls split across 09-09 periods, most recently
20 July 2007 of course, with 81.1 mm in just under 15 hours.

Peak intensity 80 mm/h at 1214z; but 60 mm/h was attained for only 49
sec in all. Highest hourly fall 30.4 mm (60 min from 1157z), just
exceeding the previous record (at this site since 1987) of 30.2 mm on
20 July 2007. Highest clock-hour fall 29.6 mm commencing 1200z.

The day max 09-18h of 13.4 °C also equalled the August 09-09h record,
set on 3 August 1986, although it seems likely to be exceeded by 0900
tomorrow morning.

Regards
Stephen

Rainfall here (NE Surrey/Gt London border) was at a guess
less than 0.5 mm (no automatic instruments). However, the afternoon
was extremely gloomy, almost needing the light on at 4 pm. Very
ominous but it came to nothing. A very cool afternoon "spoilt" by a
max of 17.5°C at 1100Z, otherwise 13-14.
I remember 3 Aug 86; heavy thunderstorm, max 14, moderate
NE'ly and almost daytime darkness for a spell while Amsterdam,
according to VOLMET, had a temperature of 34°C with Brussels and Paris
not far behind.

Tudor Hughes, Warlingham, Surrey.