Wall cloud - Stoke-on-trent - 21st July 10

[Glyn Jones]

Discerned from radar and IR sat images, at 21.15 to 21.45 I watched a smaller cell merge with a larger cell nearer Newcastle-under-lyme. Position was Forge Lane, Etruria, Stoke-on-trent. Roll cloud lifted to form shelf along a strengthening gust front, which was blown east by the outflow of the larger cell. Updraft showed low condensation with variable motion, which moved away from the core of the larger cell. Twenty minutes later (A500 roundabout) a clearer view revealed a larger wall cloud north of the city centre (was so surprised I texted Chris!). Only one cg seen, but at least two thunderclaps.

Will pop some pics up, but full set here: http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=38004&posts=2

[Glyn Jones]

Second report from the Tunstall area confirming a wall cloud. Had more time to look into this today, reckon a large cell moved up from SSW and encountered the bank between Newcastle and Stoke which disrupted the inflow from the eastward side. This disruption split the gust front and the eastern portion wrapped itself up into a small updraft (possibly orographically enhanced by the upslope of Basford, Porthill, etc). This smaller updraft weakened as it moved out of view, and at the same time the larger cell cleared the bank to the north and was free to gulp up the residual moist air left over from the weak cells collapse. The sudden gulp strengthened the eastern side and formed the lowering. Wind was slight apart from a burst of outflow as the smaller cells gust front passed (blown by the main cell outflow). Thus no funnel/tornado possible but pure uplift and vorticity formed the wall cloud. Not a severe situation by any means: no hail, minimal sferic activity at time of obs (more further north looking at ATD), strong precip core evident on larger cell but no obs of rain rate, no gusts. Hence I didn't feel it necessary to submit a report.

[Sean Benneyworth]

Why do I have to be a few thousand kilometres away when some good stuff happens???!!!

[Glyn Jones]

Don't know Sean, but it happened to me too - while in the states the UK had several funnels and a T2 (although I did have my fair share of thundery weather!).

As long as we alternate in future, I'm happy