Storm & Convective Discussion - 20th August 2015 onwards

[Nick F]

Brightening up here in south London south of rain band, with sun popping out, still pretty overcast, but should help build some CAPE.

[Flash bang flash bang etc]

If I wasn't stuck inside a roof cavity in central London I imagine i'd be seeing some rather nice convective looking skies - LoL

[Nick F]

If I wasn't stuck inside a roof cavity in central London I imagine i'd be seeing some rather nice convective looking skies - LoL

Not missing much, a lot of low cloud moving NE to SW beneath anything potentially convective.

[NO LONGER POSTING]

More sun = better chances of a rumble

[Mark Neal.]

More sun = better chances of a rumble

Very true, though its hard to get the sun to make an appearance here, stuck right in the frontal band!

[Flash bang flash bang etc]

Keep checking blitzy but increasingly it looks like any activity is and will continue to be patchy and not very organised. At least it means I'm not missing anything particularly exciting while I'm in here :-)

[Flash bang flash bang etc]

Hehehe check out the EYEsle of Wight on rain radar! :-D

[Mark Neal.]

Radar looks encouraging towards the South. Very dark echoes showing on radar. 

[NO LONGER POSTING]

Met agree

Latest indications are that the most intense rainfall may be expected across parts of southeast England and the southern portion of East Anglia this afternoon, as brightening skies supply extra energy, leading to development of slow-moving thundery showers.

[Biggin]

Did I just hear a rumble? Looking good in the SE  http://www.raintoday.co.uk

[Biggin]

CONVECTIVE / STORM FORECAST  MONDAY 24TH AUGUST 

 

Valid: 24/08/2015 0600z to 25/08/2015 0600z

 

convmap_240815.png

 

Synopsis

Negatively-tilted short-wave upper trough will move NE across NW Europe on Monday, a deep surface low, that deepens in the left exit region of strong jet rounding base of this upper trough, will track NE across N France before moving out into the N Sea. An active occluded front wrapping around this low will become slow-moving across S England today, bringing heavy convective downpours with risk of thunder. Further north, cold front will become slow-moving across N Scotland, with a risk of convective rainfall bringing isolated thunder.

 

... SE ENGLAND ...

 

Embedded convection is likely along a wrap around occluded front which will overspread SE England and southern E Anglia as low moves NE across N France/English Channel. Although any thunder and lightning will likely be isolated along this front, given weak lapse rates, localised torrential downpours may bring up to 20mm in a short space of time leading to localised flooding.

 

Clearer skies with sunny spells to the south of the front across the north French coast may spread N across the far SE of England this afternoon, which will steepen lapse rates to build 300-500 j/kg CAPE, which combined with large scale ascent in vicinity of low moving NE and dry air intrusion spreading N from France, may allow a few thunderstorms to develop here. Strongest wind shear will be further east on the near continent, so storm organisation will be limited, the main threat will be torrential rainfall, up to 20mm/per hr, leading to localised flooding. Wind convergence along SE coasts/Channel may lead to some funnels or brief/weak tornadoes with more buoyant updrafts. A Marginal risk of severe weather area, mainly for excessive rainfall, has been put across far SE, where strongest instability appears most likely.

 

... NE SCOTLAND ...

 

Some modest instability, 100-200 j/kg CAPE, is indicated by GFS along/just north of slow-moving cold front across NE Scotland, so there is a risk of isolated thunder and lightning here with heavier downpours moving NW along front, with a risk of localised flooding.

Thats looking spot on Nick judging by the radar

[10 Days Away]

Sun is out in south Kent.... feeling warm and hopefully get some convection kicking off soon.

Edited August 24, 2015 by TN26

[Nick F]

Sferics to south of London recently, near Tonbridge, Kent and Dorking, Surrey.

[Neilsouth]

Did I just hear a rumble? Looking good in the SE  http://www.raintoday.co.uk

 

I thought I did as well, chucking it down now 

[East_England_Stormchaser91]

Definite thunder in Peterborough despite no sferics shown.

[Harry]

View to my SE (from C London) - looks like absolutely torrential rain - skies look thundery to me but I am yet to notice anything electrical - blitzortung confirms this.

[East_England_Stormchaser91]

Very low deep booming! Wow! Localised flash flooding too on the A47 I've been told!

[Biggin]

View to my SE (from C London) - looks like absolutely torrential rain - skies look thundery to me but I am yet to notice anything electrical - blitzortung confirms this.

Just had a couple of claps of thunder here Harry.

[Winter Cold]

Certainly some nice cloud scapes building around Sheffield with the band approaching, ill keep a listen out for a few rumbles later

[stainesbloke]

Should be some pretty beefy showers if more clearance/sunnier skies can move up into the SE. Had some torrential rain so far, enjoyable occasionally, so much better than useless drizzle!

[Nick F]

Getting a few flashes and rumbles in New Addington near Croydon.

[Harry]

Just had a couple of claps of thunder here Harry.

 

Indeed, no sooner as I type that a couple of pings show up on blitzortung. 

 

Unless its overhead I have no chance of hearing thunder in this glass box

 

Hope that theres something occurring when I go out for a cig between 3 and 3:30

 

Rash of sferics showing up now near the Wash

Edited August 24, 2015 by Harry

[East_England_Stormchaser91]

Just witnessed what I think is a microburst!! In shock!

[ChezWeather]

Kicked off to the east of here over Newark 

[Winter Cold]

Yes that looks good just to my SE, although running the radar it now looks like everything is moving directly west. Forecast is for the rain to push up from the south today but it might not make it looking at this angle....