Uk General Convective Discussion & Forecasts, 28th August 2012>

[MP-R]

Gutted that I missed a thunderstorm in Yatton this afternoon whilst being in Cardiff. Granted there was torrential rain there in two bursts between 1-3pm before it cleared up but family at home said there were quite a few claps and rolls of thunder from the band that has been posted in a radar caption above this afternoon and a total of 15mm. Only the 6th day of thunder this month then lol.

[Nick F]

Valid: 30/08/2012 00:00 - 31/08/2012 00:00

Headline: ... THERE IS A RISK OF THUNDERSTORMS FORECAST...

Synopsis

Deep upper trough continues east across the UK during Thursday, with surface low pressure extending south across the Norwegian and North Seas. A northerly flow will develop across the UK with a shortwave trough moving south across central and eastern England during the morning and early afternoon.

... E WALES, CENTRAL, SOUTHERN AND EASTERN ENGLAND ...

Cool northerly flow will still be unstable across E Wales, central and eastern England on Thursday, where surface moisture will be greatest, which combined with surface heating and cold mid-levels of upper trough, will generate sufficient CAPE for scattered heavy showers and thunderstorms to develop. Vertical shear will be generally weak, though strong southbound jet overlap from the west in the afternoon along with shortwave trough moving south may allow storms to organise into bands with an attendant risk of localised flooding in a few spots, along with hail and gusty winds. Storms should fade after dark.

http://www.netweather.tv/index.cgi?action=convective;sess=262fc2de82f02f0930654fbc7b337cab

[Coast]

ESTOFEX have a level one for Channel coasts and the North Sea today?!!!!

Storm Forecast

Valid: Thu 30 Aug 2012 06:00 to Fri 31 Aug 2012 06:00 UTC

Issued: Wed 29 Aug 2012 23:04

Forecaster: GATZEN

SYNOPSIS

An intense trough amplifies across western Europe. A cold front will enter the west Mediterranean at the end of the period. A frontal wave may develop ahead of the trough across the Czech Republic. Ahead of the cold front, a moist air mass is present from the west Mediterranean to the Alps, eastern Germany, and southern Sweden. Latest soundings indicate steep low-level lapse rates in the northern portions of the warm air mass and steep mid-level lapse rates in the south from southern France to the Alps.

DISCUSSION

North Sea, The Channel

Near the base of the trough, numerous showers and thunderstorms are forecast across the North Sea. Rather steep lapse rates will be present. The best potential of waterspouts is expected from the region south of the British Isles to the coasts of The Channel and the Benelux countries, where best moisture and weakest vertical wind shear are forecast.

Sure was a bit of convection going on in The Channel at 0660 hrs this morning but it seems to have cleared currently, maybe some heating today will help?

UKASF are backing up NW and ESTOFEX with:

Synopsis:

Sharpening upper trough continues to migrate eastwards across the British Isles, with a low at the surface. A shortwave combined with cold mid-levels will initiate convection.

Discussion:

Scattered showers and a few thunderstorms are forecast, especially across East Anglia and the SE as 500-600J/kg CAPE becomes available in response to diurnal heating. 20kts DLS may allow cells to become fairly-organised, capable of producing some small hail in heavy cores. With the jet aloft moving eastwards into western Britain later, any linger showers over the Midlands/W Country by late afternoon may benefit from a rapid increase in DLS.

Sferic coverage is likely to be fairly sporadic, perhaps more concentrated over Kent, Sussex and Essex with low-level convergence along the coasts aiding convection initiation. With the departing upper trough and strong surface ridging from the west, showers/storms will rapidly decrease in coverage during the late afternoon and evening hours, with general focus shifting to the southern North Sea.

Nothing updated from SkyWarn or TORRO yet so on with some charts and fingers crossed!

Owwww, is that my corner of the World?!!!

Yes, it is!

Unusual jet:

A few hundred Joules of MLCAPE:

Convergence and shear over the SE:

Some spout chances:

Wowsers!!! look at the lower level lapse rates!!!!!

Of course there's more rain!

Maybe even a slight tornado risk?

MCS propagation:

Can we get some heat into the day to achieve the diurnal heating?

Borderline......

But still warm:

So in simple terms, what does all this malarkey mean in the South and South East?

Possibly some thunder and lightning?

Better than a poke in the eye with a damp cod eh?

[Harry]

Will I get my first storm in AGES?? Will any London bound storms co-incide with my staff meeting this afternoon, anytime after 3pm?

I'd take a solitary loud peel of thunder at this stage...gagging for a storm!

[Coast]

Will I get my first storm in AGES?? Will any London bound storms co-incide with my staff meeting this afternoon, anytime after 3pm?

I'd take a solitary loud peel of thunder at this stage...gagging for a storm!

I feel your pain Harry! It's certainly not odds -on, but there's a lot of finger crossing going on in the SE I guess right now and we need all those ingredients to come into play. Here's a projection of the low moving East and the following front:

[Chris W]

Does anyone have a strike map for the whole of yesterday's action? I was so pleased to see an hour-long storm and will be content for this year if nothing else happens here. A storm at home would ice the cake, but I'm happy with what came yesterday.

As for today I'm not expecting much, though we've had a fair bit of sun this morning and had a sharp 5 minute downpour an hour or so ago - if the sun shines this aft maybe we'll get something later.

[TEITS]

Im not expecting storms today and to be honest I don't know why these are being forecasted.

[Norfolk Sheep]

Succession of heavy showers from 11am, a brief glimpse of the sun now and again

[Kent Snow]

Quite a few sharp showers today so far. One recent bolt of lightning plus thunder.

[Nick F]

Quite a few sharp showers today so far. One recent bolt of lightning plus thunder.

Yes, Atd showing strikes recently across North Kent, aswell as strikes across eastern Suffolk and Norfolk.

Further west, convection looks rather supressed looking out the window here in west London.

[Coast]

Wind is really cranking up around Benny Hill but the rain has skirted around us. Nothing remotely like thunder but I'm just going to check the clouds!

[Lynxus]

Convection now appearing in the North/ North west.

Fingers crossed.

[Stormraider]

Quite a lively shower skirting to my East, large-ish rain drops as it passes... bit of hail too. Wind very gusty.

[Harry]

Dank looking skies here, not what one would associate with convective potential.

[Lynxus]

its got damn humid round here in the last hour or so.

Phew. its warm.

SFERICS just NE of Chelt.

Edited August 30, 2012 by Lynxus

[Cheshire Freeze]

Very heavy shower developed virtually over head.....looks like core just east of here but HUGE spots of rain, dark, low ragged cloud base and gusty winds. Lots of scud too. People SE of here could get a storm out of it

[Cheshire Freeze]

Looks like a brief affair, seems to have died a death as quick as it started

[gottolovethisweather]

Looks like a brief affair, seems to have died a death as quick as it started

Still in the NSC then Crewe, so close too.

[Karl83]

No eye candy for the forseeable future.

[AWD]

No eye candy for the forseeable future.

There is always You Tube!

[East_England_Stormchaser91]

The main thing that has alarmed me is how cold it feels! I can really feel an Autumnal feel to things now, apparantly down to 6 degrees overnight here too!

[Dean E]

Very deep rumbles of thunder here on the south coast... was a surprise!

[Cheshire Freeze]

Still in the NSC then Crewe, so close too.

Yep, still there.....it's always close but no cigar here lol

[Karl83]

There is always You Tube!

Ha ha this is true! Its not gona cut the mustard though lol.

The main thing that has alarmed me is how cold it feels! I can really feel an Autumnal feel to things now, apparantly down to 6 degrees overnight here too!

Yeah I've noticed it too. Feels chillier in the mornings.

Edited August 30, 2012 by Thunder_Bolt

[Lynxus]

Ha ha this is true! Its not gona cut the mustard though lol.

Yeah I've noticed it too. Feels chillier in the mornings.

Yep just got back from a run and it really does feel like summer has ended. yet everything is still bright green. very odd.

Then again, if the jet keeps up like it has been this year we could be in for a cold and snowy one.

Edited August 30, 2012 by Lynxus