Severe thunderstorm, Wokingham,1723z to .... moving away to north now, still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the storm was
quite dramatic, with the rain suddenly easing, allowing the vis to rise to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html

Bernard,

Similar storm here in Three Mile Cross. Plenty of thunder but without quite
the amount of rain you have just had and the same sharp ending as it moved
north. I have just heard that parts of The Holt School have been flooded
quite badly and this will be largely due to run off from the flat roof of
one of the blocks which the drains could not cope with. I would be very
interested to hear what the rainfall total was for this storm and also the
rainfall rate as I will probably be talking to the Insurance company
tomorrow!

The last time this happened was on a Friday night in 1994 some time around
June when there was another torrential downpour and the same parts of the
school were flooded. If you do happen to recall that storm and have
rainfall figures for it I would be very interested in a comparison with
tonight's event.

Regards

Steve Thomas




"Bernard Burton" wrote in message
...
Severe thunderstorm, Wokingham,1723z to .... moving away to north now,
still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the storm
was
quite dramatic, with the rain suddenly easing, allowing the vis to rise to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to
the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html

"Steve Thomas" wrote in
:

The last time this happened was on a Friday night in 1994 some time
around June when there was another torrential downpour and the same
parts of the school were flooded. If you do happen to recall that
storm and have rainfall figures for it I would be very interested in a
comparison with tonight's event.

24th June 1994 - I was in Reading at the time, can still remember it
vividly.

Someone actually has put a film of the storm from Essex on youtube, you can
see the "roll cloud" ahead of the storm with the vivid and frequent
lightning:

http://www.youtube.com/watch?v=r-pyS9Cj2yU

Richard

Only 4.2 mm fell here in Stratfield Mortimer ... One or two of the
thunderclaps I'd just about describe as 'loud/heavy' otherwise only a
'tlr' here. The clearer skies to south-west were visible through most
of the period of quite steady rainfall. Almost 2 hours thunder and
lightning, though, so no complaints - only the fifth thunder-day so
far this year here, and remarkably the first to have more than a
single 'bang'.

Stephen

In message , Steve Thomas
writes
Bernard,

Similar storm here in Three Mile Cross. Plenty of thunder but without quite
the amount of rain you have just had and the same sharp ending as it moved
north. I have just heard that parts of The Holt School have been flooded
quite badly and this will be largely due to run off from the flat roof of
one of the blocks which the drains could not cope with. I would be very
interested to hear what the rainfall total was for this storm and also the
rainfall rate as I will probably be talking to the Insurance company
tomorrow!

The last time this happened was on a Friday night in 1994 some time around
June when there was another torrential downpour and the same parts of the
school were flooded. If you do happen to recall that storm and have
rainfall figures for it I would be very interested in a comparison with
tonight's event.

Regards

Steve Thomas




"Bernard Burton" wrote in message
...
Severe thunderstorm, Wokingham,1723z to .... moving away to north now,
still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the storm
was
quite dramatic, with the rain suddenly easing, allowing the vis to rise to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to
the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html





Steve,

For what it's worth, we had 9mm in 35min at Middle Assendon, nr Henley,
today, same storm cell as Bernard B. HTH

Luck with the insurers!

--
-----------------------------------------------------------------------
John P. Verge Middle Assendon, Henley, Oxon
-----------------------------------------------------------------------

"Richard Dixon" wrote in message
9...
"Steve Thomas" wrote in
:

The last time this happened was on a Friday night in 1994 some time
around June when there was another torrential downpour and the same
parts of the school were flooded. If you do happen to recall that
storm and have rainfall figures for it I would be very interested in a
comparison with tonight's event.

24th June 1994 - I was in Reading at the time, can still remember it
vividly.

Someone actually has put a film of the storm from Essex on youtube, you can
see the "roll cloud" ahead of the storm with the vivid and frequent
lightning:

http://www.youtube.com/watch?v=r-pyS9Cj2yU

Richard

That storm was an MCS (Mesoscale Convective System) gave a lot of rain over East
Anglia IIRC.
Used that one for years as a case example at work!

Will.
--

Steve,
I have just been looking at the figures from the AWS at Emmbrook.
The TBR logged 23.2 mm in 32 minutes, but correcting for expected losses
that should be equivalent to 25.8 mm.
What is astonishing are the values for rain rates.
Here is the list of the one minute mean and max rain rates during the
storm, mm/hr (all times GMT, and time is minute ending at):
Time mean max
1809 12 16
1810 34 49
1811 40 46
1812 27 34
1813 27 43
1814 40 43
1815 40 49
1816 87 107
1817 101 177
1818 121 177
1819 154 314
1820 121 314
1821 127 506
1822 94 177
1823 101 177
1824 94 227
1825 148 314
1826 101 314
1827 20 36

The maximum indicated rain rate was 506 mm/hr at 1820z. Tips are timed to
the nearest 500 ms, so there is an error bar about 200 mm/hr wide at that
rate.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html
"Steve Thomas" wrote in message
...
Bernard,

Similar storm here in Three Mile Cross. Plenty of thunder but without
quite
the amount of rain you have just had and the same sharp ending as it moved
north. I have just heard that parts of The Holt School have been flooded
quite badly and this will be largely due to run off from the flat roof of
one of the blocks which the drains could not cope with. I would be very
interested to hear what the rainfall total was for this storm and also the
rainfall rate as I will probably be talking to the Insurance company
tomorrow!

The last time this happened was on a Friday night in 1994 some time around
June when there was another torrential downpour and the same parts of the
school were flooded. If you do happen to recall that storm and have
rainfall figures for it I would be very interested in a comparison with
tonight's event.

Regards

Steve Thomas




"Bernard Burton" wrote in message
...
Severe thunderstorm, Wokingham,1723z to .... moving away to north now,
still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and
several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local
roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the storm
was
quite dramatic, with the rain suddenly easing, allowing the vis to rise
to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to
the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through
unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html

Steve,
Re your query regarding the 1994 event. As others have already said, it was
on the 24th June 1994, and we measured 43.6 mm at Emmbrook.
Regards
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html
"Steve Thomas" wrote in message
...
Bernard,

Similar storm here in Three Mile Cross. Plenty of thunder but without
quite
the amount of rain you have just had and the same sharp ending as it moved
north. I have just heard that parts of The Holt School have been flooded
quite badly and this will be largely due to run off from the flat roof of
one of the blocks which the drains could not cope with. I would be very
interested to hear what the rainfall total was for this storm and also the
rainfall rate as I will probably be talking to the Insurance company
tomorrow!

The last time this happened was on a Friday night in 1994 some time around
June when there was another torrential downpour and the same parts of the
school were flooded. If you do happen to recall that storm and have
rainfall figures for it I would be very interested in a comparison with
tonight's event.

Regards

Steve Thomas




"Bernard Burton" wrote in message
...
Severe thunderstorm, Wokingham,1723z to .... moving away to north now,
still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and
several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local
roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the storm
was
quite dramatic, with the rain suddenly easing, allowing the vis to rise
to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to
the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through
unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html

We had a similarly intense storm in Lower Earley yesterday evening -
9mb video here http://homepages.nildram.co.uk/~paul...torm190607.wmv

The video gives an impression of the close CG strikes, although none
really caught on film, and the camera work is a bit shaky!

Bernard,

Thanks very much for your information and thanks to the others who chipped
in. The damage to the school was not as bad as it was in 1994 but the cause
was the same - intense rainfall rate overwhelming the drains. Still we seem
to have got off lightly compared to other parts of the country.

Regards

Steve Thomas

"Bernard Burton" wrote in message
...
Steve,
Re your query regarding the 1994 event. As others have already said, it
was
on the 24th June 1994, and we measured 43.6 mm at Emmbrook.
Regards
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html
"Steve Thomas" wrote in message
...
Bernard,

Similar storm here in Three Mile Cross. Plenty of thunder but without
quite
the amount of rain you have just had and the same sharp ending as it
moved
north. I have just heard that parts of The Holt School have been flooded
quite badly and this will be largely due to run off from the flat roof of
one of the blocks which the drains could not cope with. I would be very
interested to hear what the rainfall total was for this storm and also
the
rainfall rate as I will probably be talking to the Insurance company
tomorrow!

The last time this happened was on a Friday night in 1994 some time
around
June when there was another torrential downpour and the same parts of the
school were flooded. If you do happen to recall that storm and have
rainfall figures for it I would be very interested in a comparison with
tonight's event.

Regards

Steve Thomas




"Bernard Burton" wrote in message
...
Severe thunderstorm, Wokingham,1723z to .... moving away to north now,
still
the odd rumble heard.
At its height there were between 15 and 30 flashes per minute, and
several
CG very close.
Rain was torrential 1813z to 1825z, with vis reduced to 600m. Local
roads
are awash,
and I wonder how people are coping on the nearby M4.The end of the
storm
was
quite dramatic, with the rain suddenly easing, allowing the vis to rise
to
over 5km in a matter of seconds, revealing a cloud edge and blue sky to
the
SW.
As the storm approached I switched off and disconnected all PCs and
unplugged leads to the roof. The ultra-sonic anemometer was the only
instrument to be kept going, and it semes to have come through
unscathed.
I am in the process of powering up again, but all equipment seems to be
working.
No thunder heard for 10 mins now, 1850z.
--
Bernard Burton
Wokingham, Berkshire, UK.

Satellite images at:
www.woksat.info/wwp.html
or
www.btinternet.com/~wokingham.weather/wwp.html