"Nick" wrote in message
...
Around 1420 I heard thunder from Southampton, the first time I've
heard thunder in the UK since 15/6/08. Seems to be a locally
developing shower, what's odd is that the showers are developing S of
here, towards the sea; normally at this time of year they develop
overland. A contrast to the last couple of days, which were rather
uneventful round here, except some brief heavy rain around 0930
yesterday.

Nick

I'd hazard a guess that localised convergence has come into play with the
general WNW'ly flow being backed towards the coast aiding the development of
showers where the air streams converge inland. I've witnessed some lengthy
storms in the Bournemouth/IOW area due to this effect.
The relatively coarse GFS had a stab at it earlier with the winds but failed
to resolve the showers http://www.wetterzentrale.de/pics/Rmgfs095.gif

Jon.