Convective / Storm Risk Discussion - 21st July 2013 onwards

[NO LONGER POSTING]

Cells over the channel expanding... Lightning increasing South coast south east and south west looks lively folks!

[jessandjon]

Wunderground closest weather station thing says humidity 86% sorry to seem dumb what Exactly does it mean when it is rising?

Sorry question sounded better in my head!

Edited July 21, 2013 by jessandjon

[nanu]

Don't be daft we don't get things like that here properly be lucky to get drizzle!!

nah.. honest they are actually getting pretty active crossing the channel

[nitro_deluxe]

Oh to be on Portland Bill right now...

Looking very very good indeed.

[imriecm]

I thought someone mentioned that it was moving N/NE slightly into Hampshire, but the activity appears to be more on the Western side, what's the deal, is Hampshire/Surrey likely to get anything from this, I'm not sure if it's mean to intensify again at all?

[davehsug]

poole harbour webcam

 

http://www.intheelements.co.uk/blog/webcam/poole-harbour-webcam/

There seem to be lots of children playing with it so theres no chance of seeing owt. Need a stationary one!

[Dorset Weather]

sorry about the dodgy pic but just to give you an idea. about 20 miles away according to the strike alert, flashing approx every few second

Edited July 21, 2013 by Dorset Weather

[paul m]

poole harbour webcam

 

http://www.intheelements.co.uk/blog/webcam/poole-harbour-webcam/

Just wondering what the bloke in the water is doing on this webcam????. Been in the same place for 5 mins..Bit late for fishing

[nanu]

poole harbour webcam

 

http://www.intheelements.co.uk/blog/webcam/poole-harbour-webcam/

sorry but it would help if the cam stayed in one place and not zoomed in on the water by morons!!

[James86]

Hi,

I'm James, read the forums for a few months not but finally signed up. Based in southampton so hoping for some action tonight!

[tara303]

Oh come a bit more north westerly, quicker!

 

I moved to Ireland from the south uk last year - one of the many reasons being possibly more storm activity than the UK!!! lol... will be a radar watch for me tonight, unless anyone knows different??? Not working til 6pm tomorrow so can stay up late if I have to...

 

Happy storm days you southern uk peeps!!!

[Carl46Wrexham]

There seem to be lots of children playing with it so theres no chance of seeing owt. Need a stationary one!

 

Unwatchable unfortunately...like a drunken sailor has been left in charge of it........shame.

[Tom Jarvis]

Can you send them a little eastwoods as there is a lot of energy here in East Sussex after a cloudless day here

[Tim B]

Wunderground closest weather station thing says humidity 86% sorry to seem dumb what Exactly does it mean when it is rising?Sorry question sounded better in my head!

 

It means there is more moisture in the atmosphere and moisture forms clouds, so the more of it during a thundery breakdown the better.

[poseidon]

looks to be moving NW from satellite pics

[Allseasons-Si]

There seem to be lots of children playing with it so theres no chance of seeing owt. Need a stationary one!

 

yes,we need a set piece on the table,not all over the floor lol.

[Wilxy]

Wiltshire looks prime spot at the moment along with Hampshire.

[ChezWeather]

Im looking out to sea straight towards the cell that is going mad off Weymouth, shame im abit too far away and haze / mist is blocking the view 

[jessandjon]

It means there is more moisture in the atmosphere and moisture forms clouds, so the more of it during a thundery breakdown the better.

Thank you. So it doesn't mean we wil get thunder just sticky!!

[Robbie Garrett]

Bugger... It's decaying and starting to head more east towards as it goes over the Channel. 

 

[butler_son]

Just seen some big old cloud coming from the south, seen a couple of faint flashes and a small growl.

[Stuart]

Upper ridging persists across Central Europe and the North Sea, while an upper trough slowly approaches from the Atlantic. On the forward side, advection of high WBPT plume northwards across the British Isles will occur, destabilising in response from either various shortwave troughs or diurnal heating (or both). Several bouts of thunderstorm activity is possible during this forecast period.

 

Discussion:

... CS + SW ENGLAND, SE WALES, S MIDLANDS ...

Ongoing thunderstorms currently over northern France this evening, associated with a shortwave trough, will continue to drift northwards across the English Channel overnight and through the early morning hours, becoming increasingly elevated. Further elevated development is possible ahead and behind this cluster of thunderstorms as the moisture plume destabilises. Therefore, elevated thunderstorms are expected across parts of Hampshire, Dorset, Isle of Wight during the early hours, migrating further north across the West Country and possibly SE Wales/S Midlands/Home Counties towards and after dawn. Slow-moving storms with PWAT >30mm could cause some local flooding, and given degree of instability (MLCAPE up to 1,500 J/kg) some hail up to 1.5cm in diameter is possible in any stronger cores, particularly in Dorset/Hampshire/IoW, before the storms weaken in intensity and coverage during Monday morning.


... MIDLANDS, N WALES, EAST ANGLIA, HOME COUNTIES ...

There is likely to be various amounts of cloud debris from decaying overnight elevated convection drifting slowly northwards, which may inhibit strong insolation at times. Nonetheless, low-level wind convergence and high surface temperatures/dewpoints (30C/19C being a conservative range respectively) coupled with the progress of an upper trough is likely to result in scattered surface-based thunderstorms during the afternoon and evening hours, becoming more widespread with time. CAPE >2,500 J/kg will result in some very electrically active thunderstorms, with hail up to 3.0cm in diameter possible. Shear is rather weak, so cell organisation is likely to be limited at times, but backed surface winds with slight directional shear may allow a funnel or weak tornado to form briefly. Again, slow-moving downpours and PWAT in the high 30's mm locally could result in local flooding given dry ground currently present. Given hail and rainfall thresholds, this is borderline SVR and may require an upgrade during Monday if development continues to look likely (dependent on cloud clearance etc).


... NW ENGLAND, SW SCOTLAND, YORKSHIRE, NE ENGLAND ...

Gradual upscale growth of scattered thunderstorms is expected during Monday evening as destabilisation continues to occur along the moisture plume axis. Therefore scattered thunderstorms are likely to form over these areas through Monday evening and night, the development extending progressively further northwestwards across the SLGT and perhaps ISOL areas. Heavy downpours may result with some localised flooding, with some hail also possible in any stronger cores.


... W/NW IRELAND, W NORTHERN IRELAND ...

Scattered showers and a few thunderstorms are expected to develop during the afternoon and evening hours in response to diurnal heating and the development of a low pressure centre over the Atlantic just north of Connaught. Hail up to 1.0cm in diameter is possible, with storms gradually moving offshore to the northwest through the evening hours.

 

 

http://ukasf.co.uk/storm-forecasts/256

Edited July 21, 2013 by Stuart

[ZONE 51]

On the points you make you are probably correct, problem is if it doesn't clear by the time the sun comes out, we will not get the high temps as everybody has suggested, then our chances diminish badly for imported storms or home grown, last minute things like this can always cause dampers for heat lovers and storm lovers alike, and in winter snow lovers

I expect there to be enough daytime heat through tomorrow to activate storm creation. anything from 25C is enough for the storms. Not any less effect on what is expected Monday night either I don't expect. I can understand why you say this though.

 

Edited.

Edited July 21, 2013 by ElectricSnowStorm

[jtay]

sorry about the dodgy pic but just to give you an idea. about 20 miles away according to the strike alert, flashing approx every few second

 

Yep, can confirm that. Sat in the garden looking SSW.

 

Plenty of activity in there. I reckon it's picking up.

[ChezWeather]

Typical that i see Chesterfield smack in the middle of UKASF moderate zone while im down in Cornwall