In uk.sci.weather on Tue, 27 Apr 2004 at 19:35:39, Martin Smith wrote :

I was on the allotments at One Tree Hill, Honor Oak Park when the
storm started at about 1650Z, it wsa too heavy to leave so I took
shelter in a hut, which has a polycarbonate roof, torrential rain
thunder and lightening continuously for over an hour, a couple of
minutes after 1700Z the hail became lager
^^^^^
Must...resist...making...comment...

and larger, the rain had
dropped of and I thought it was all over, for about 3 minutes there
was hail up to 25mm giving a light scattering, some of it apeared
to be conical in section, some of it was smashing on the polycarbonate
roof. Never seen anything like that before, truly awsome.
Rain finally eased off enough to go home about 1730Z.
--
Paul Hyett, Cheltenham