The whole northern horizon is scarred with cells - a line going northeast to southwest. Still exploding up now as I type.

Bracknell had 9.8mm in about 15 minutes.

http://www.weatherfamily.org/bracknell/ 

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That is one impressive looking cumulonimbus cloud, I must say.

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A quick glance at the outputs are producing some very tasting lookingstorm potential overSouthern Engand and the SouthEast by this time next week (Wednesday night). It is a very long way off in forecasting terms, of course, and I still need to bone up on humidity and dewpoint levels, etc, to understand and get a better idea of it all but initial impressions are looking good anyway.

But I did get a little excited when I looked at this (pressure for this time next week): http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=gfs&MODELLTYP=1&BASE=-&VAR=pslv&HH=180&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD =

I'm quite confident on this thundery stuff for that middle part of the week but what's going to happen once that's all done and dusted is really anyone's guess.
I'm tempted to say that it'll be a little cooler and changeable in nature thereafter but that's really my own take on things but chances are that it'll take us back to the hot and dry weather anyway.

PS: Excellent cumulonimbus photos, guys!

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My wife said few drops of rain over my flat area and heard rumble of thunder around 5.30pm.  It was hard to see the cell clouds due to thick haze.

It occurs to me, you can not see a thunder cloud develop right over you? Only at distance can you see the height/cauliflowers and the anvil? So if one develops right over your head, the first real sign is lightning! ! jeeeeeeeeeeeeps!!!!!

There would be several signs that a thunderstorm was developing overhead before llightning occured, not least the fact it would be getting pretty dark! An increase in wind would indicate inflow into the storm as well.

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That comment was a bit tongue in cheek, of course there's other signs of T-Storm developing above oneself!!

Come to daddy. http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=gfs&MODELLTYP=1&BASE=-&VAR=prec&HH=192&ZOOM=1&ARCHIV=0&RES=0&PANEL=0&LOOP=0&INFO=0&WMO=

But of course, it being eight days away, that is light years in forecasting terms anyway.

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Agreed that chances of thundery conditions is now increasing into next week, but Sunday night looks decent for import potential. Some of the output this morning brings imported storms into the Southeast.

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Will we get any action in the East Midlands...........? Leicester to be more specific, and would it be home-grown, rather than imported dirty stuff..?
VSC

According to this thread on uk.sci.weather (the 7th post), someone who lives 100 metres south east of the Met Office Roundabout in Bracknell recorded 24mm of rain in yesterday's thunderstorm, including some hail.

https://groups.google.com/forum/#!topic/uk.sci.weather/uETb7b9N6JQ

He certainly was in the sweet spot!

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I say that was possible since some of the central cores of these storms were very intense, 150mms per hour in some.

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Well some cells certainly punched through as forecast. I missed tracking them as I was playing cricket yesterday evening but could see the tops of these cells even from S Hampshire.

On to today and the sweet spot will be far SE Wales and into Avon/Somerset for cell formation.
Then we have Sunday evening . . . .

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I wouldn't ignore SE Scotland and NE England, Neil. A chance of convergence storms breaking out there this afternoon.

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We have the first signs on the radar of cells popping up just to the NW of Newcastle.

EDIT: Something brewing north of Swansea as well.

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...and now Cornwall too.

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It all looks a bit disorganised unfortunately, with cells firing and dying quite quickly.

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Ok, beginning to understand cap breaking and cape.... with regards to thunderstorms. ... thanks all who helped.
What are and how do "CONVERGENCE STORMS" OPERATE??
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Convergence is one method of providing extra lift to unstable air, often aiding in breaking though a cap if one exists.

It is a result of converging wind fields in a particular location (e.g. winds from the W meeting winds coming in from the E). Where they meet the air is forced upwards (providing extra lift).

One common scenario when this might happen is when sea breezes kick in on hot days (when the land becomes much warmer than the sea), and meet the prevailing wind inland which is coming in from the opposite direction. Or it might be that 2 sets of sea breezes meet in the middle of a peninsula, as with the big T-Storms over the interior of Cornwall that led to the Boscastle floods.

 

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Cheers, much obliged ref convergence storms. ..... thought it might be something like that, what other circmstances can thunderstorms arise?
Cheers
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Have a look here VSC...

http://www.theweatheroutlook.com/twocommunity/yaf_topics5_Library.aspx

There's a couple of very informative articles on convection - well worth a read :-)

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Ta!!!!
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Trough developing to my South over Angers and progged to move North. I shall await developments later this evening.

Convection over western fells now - combination of sea breeze converegence and orographic uplift.

I can see this ending up with some flashes and bangs later...