Storm & Convective Discussion - 16/07/15 onwards

[William Grimsley]

Lincs looks the place to be then;)

Not this time, luckily!

[Gordon Webb]

Looks like a spell of heavy thundery rain for most with the odd isolated storm maybe thrown into the mix......Expecting a fair bit of rain here but not a lightning show.

Well gibby who posts on the model thread suggested something similar and in the met office warnings they indicated an area of rain which could be heavy and thundery at times they did however mentioned localised thunderstorms in the south and East on Friday afternoon as this is a developing situation I wouldn't take anything as nailed yet it could better or worse than forecast

[Stormyking]

The latest 6z would ring out some major flood alerts if any of this pulls, Friday looks especially nasty on this latest run for parts of Central, Southern and Western areas, aka Dorset, Bristol, East Devon up to South West Midlands.

 

Before that, still looks pretty decent for potential nasty storms, especially anywhere across SoutherN Coasts, South East Coast and parts of the South West.

 

Quite a few things to note such as ML cape, looks like there would be good wind sheer too, especially Thursday Morning, with surface winds Easterly to ENE, Mid Level South South East, and the very upper winds South East! quite strong too.

 

If the surface winds become slightly more NE, and remain showing strong, my theory is storms would leave France, become Elevated, then further in the channel, those strong NE winds, would easilly bring land heat a good 30+miles out into the channel, so as the storms/showers get closer they would become more semi elevated to surface based, which in turn would bring a highest of Hail and possible possibly super cellular characteristics. 

 

Things could still easily change, but this would be my theory from all the aspects ive been keeping an eye on the last few days, im not gonna get carried away at all.

[Gordon Webb]

Its another ingredient for the mixing pot though.. 

 

More ingredients better storms 

 

 

Although he is right.. It is a tad down

More ingredients = better storms

Remember too many cooks spoil the broth

[Summer Sun]

Early warnings out from the met office

 

Issued at: 1015 on Tue 11 Aug 2015

Valid from: 0600 on Thu 13 Aug 2015

Valid to: 2350 on Thu 13 Aug 2015

 

A developing area of rain is expected to reach the south of England early on Thursday morning, before pushing north across much of southern UK during the day. The rainfall is likely to be heavy and thundery at times, with the potential for torrential downpours in places. The public should be aware of a significant risk of very localised disruption to travel due to surface water flooding. Lightning may be an additional hazard.

 

Chief Forecaster's assessment

 

An area of low pressure is expected to develop just to the northwest of Spain in the next 12 to 24 hours. This system is then expected to push north across Biscay and into the south of the UK early on Thursday. With very warm air entrained into the system, locally heavy and thundery rain is likely to develop as the system pushes across parts of England and Wales. 15 to 30 mm of rain is possible in in 6 to 12 hours, with as much as 50 mm possible very locally by the end of Thursday. The development of this system is very complex, and uncertainty in the details of this event is relatively high. As such this warning will be updated in the coming days as confidence increases.

 

Warning covers

 

Blaenau Gwent, Bridgend, Caerphilly, Cardiff, Carmarthenshire, Ceredigion, Denbighshire, Flintshire, Gwynedd, Merthyr Tydfil, Monmouthshire, Neath Port Talbot, Newport, Pembrokeshire, Powys, Rhondda Cynon Taff, Swansea, Torfaen, Vale of Glamorgan, Wrexham

 

Cheshire East, Cheshire West and Chester

 

North East Lincolnshire, North Lincolnshire, South Yorkshire

 

Herefordshire, Shropshire, Staffordshire, Stoke-on-Trent, Telford and Wrekin, Warwickshire, West Midlands Conurbation, Worcestershire

 

Derby, Derbyshire, Leicester, Leicestershire, Lincolnshire, Northamptonshire, Nottingham, Nottinghamshire, Rutland

 

Bedford, Cambridgeshire, Central Bedfordshire, Essex, Hertfordshire, Luton, Norfolk, Peterborough, Southend-on-Sea, Suffolk, Thurrock

 

Bath and North East Somerset, Bournemouth, Bristol, Cornwall, Devon, Dorset, Gloucestershire, North Somerset, Plymouth, Poole, Somerset, South Gloucestershire, Swindon, Torbay, Wiltshire, Isles of Scilly

 

Bracknell Forest, Brighton and Hove, Buckinghamshire, East Sussex, Greater London, Hampshire, Isle of Wight, Kent, Medway, Milton Keynes, Oxfordshire, Portsmouth, Reading, Slough, Southampton, Surrey, West Berkshire, West Sussex, Windsor and Maidenhead, Wokingham

 

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1439420400&regionName=se

 

A warning is also out for Friday

 

Issued at: 1023 on Tue 11 Aug 2015

Valid from: 0010 on Fri 14 Aug 2015

Valid to: 2350 on Fri 14 Aug 2015

 

An area of locally heavy rain already across many central and southern parts of England and east Wales at the start of Friday, is expected to push across the rest of England and Wales during the early morning. Rain is likely to be persistent, and may be accompanied by hail and thunder in the south and east. Rain will ease from the west during the evening, and probably become confined to eastern areas by the end of Friday. The public should be aware of a significant risk of very localised disruption to travel due to surface water flooding. Lightning may be an additional hazard.

 

Chief Forecaster's assessment

 

An area of low pressure is expected to push north then east across England during Friday. With very warm air entrained into the system, locally heavy rainfall is likely to continue as the system pushes across England and Wales. 25 to 40 mm of rain is possible in 6 to 12 hours, with as much as 70 mm possible very locally by the end of Friday. Localised thunderstorms may develop across the south and east of England during Friday afternoon, these potentially giving 15-25 mm of rain in a few hours. The development and subsequent track of this system is very complex, and uncertainty in the details of this event is relatively high. As such this warning will be updated in the coming days as confidence increases.

 

This warning currently covers all of England and Wales

 

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=map&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1439506800&regionName=se

[East_England_Stormchaser91]

The latest 6z would ring out some major flood alerts if any of this pulls, Friday looks especially nasty on this latest run for parts of Central, Southern and Western areas, aka Dorset, Bristol, East Devon up to South West Midlands.

 

Before that, still looks pretty decent for potential nasty storms, especially anywhere across SoutherN Coasts, South East Coast and parts of the South West.

 

Quite a few things to note such as ML cape, looks like there would be good wind sheer too, especially Thursday Morning, with surface winds Easterly to ENE, Mid Level South South East, and the very upper winds South East! quite strong too.

 

If the surface winds become slightly more NE, and remain showing strong, my theory is storms would leave France, become Elevated, then further in the channel, those strong NE winds, would easilly bring land heat a good 30+miles out into the channel, so as the storms/showers get closer they would become more semi elevated to surface based, which in turn would bring a highest of Hail and possible possibly super cellular characteristics. 

 

Things could still easily change, but this would be my theory from all the aspects ive been keeping an eye on the last few days, im not gonna get carried away at all.

Sounds like something that would occur on the day after tomorrow!

South coast certainly looks a pretty exciting place to be for this.

In my region, we would be looking at possible Benelux imports too!

[William Grimsley]

Latest NMM run is out and currently it looks like some widespread thunderstorms are likely in the early hours of Thursday morning for southern counties of England, especially East Devon, Dorset and Somerset. We need to take these charts as a pinch of salt and wait until tomorrow night for nowcasting. As is always the case, "Looking at charts won't change anything!".

[Rain123]

Latest NMM run is out and currently it looks like some widespread thunderstorms are likely in the early hours of Thursday morning for southern counties of England, especially East Devon, Dorset and Somerset. We need to take these charts as a pinch of salt and wait until tomorrow night for nowcasting. As is always the case, "Looking at charts won't change anything!".

So, would you say that storms more east would be less active then?

[Rain123]

Hi, this is pretty urgent so a quick reply would be appreciated.

What time are the storms due to get to the southern tip of the isle of wight roughly? Cheers.

[Biggin]

So, would you say that storms more east would be less active then?

William only posts for his area normally, as do I mostly and some others tho.

[Stormyking]

There is 2 lots im keeping an eye, 1st one is for early Thursday Morning, most of the High resolution charts say yes to Early Thursday Morning, which looks a better bet South coast, and the South West. The 2nd lot looks to be Thursday Evening into Friday which looks good for the South Coast again and the South East, actually the South East on some these runs look potentially nasty for Thursday Evening. This also included further inland too.

 

Im not going to judge Friday yet as its still 3 days away.

 

[Stormyking]

Hi, this is pretty urgent so a quick reply would be appreciated.

What time are the storms due to get to the southern tip of the isle of wight roughly? Cheers.

 Can never say for sure on times, or even they will happen, they could still easily miss us, but am about 70% confident

 

From all of what im seeing detail, I would say our best time would be Early hours Thursday probably between the hours 2am and 8am... On thursday looks a case of anything could pop up at  anytime

[Supacell]

The latest GFS shows thunderstorms touching the south coast on Wednesday night and then erupting northwards to cover everywhere from Yorkshire southwards by Thursday night. Surface based CAPE develops to the value of around 1000 j/kg briefly to the south and west of the Midlands but elsewhere it is not very impressive. However, MLCAPE I would imagine is widespread. Friday a further pulse of thunderstorms look to affect eastern England, especially East Anglia with rain in the west. The precipitation charts are a mess but also awash with torrential downpours. The storm risk does not really get north of Yorkshire with the favoured spots being further south and through the Midlands on Weds night/Thurs and then eastern England on Thurs night/Fri.

 

The latest NMM shows thunderstorms moving into the entire south coast Wednesday night and moving north on Thursday, much like the GFS. The SW will lose the storms during Thursday after a thundery night then places like the NE will get them on Friday. There is a huge amount of rainfall potential both from thunderstorms pushing north and then from a band of particularly heavy rain pushing east on Friday and sweeping away the thunder risk with it.

 

It is a messy picture but current charts would I think favour widespread torrential downpours and mostly elevated thunderstorms both by day and by night. Of more concern though is the rain with torrential downpours likely to be off and on for 24-48 hours in parts and if some of these are dropping in the region of 50mm plus per hour you can imagine the disruption that could come from this. 

[Arnie Pie]

Shooting stars or night time lightning???

Back to stream which ever

[Harry]

A forecaster's nightmare this coming up!!! A complete mess...but interesting and borderline exciting nonetheless

[Nick L]

It will be the rain that will be the most notable over the coming days rather than thunder and lightning, although there should be a decent amount of that too. Localised flooding still remains the biggest threat.

 

S Midlands and SC England could see over 2 inches of rain quite widely over a 24 hour period.

Edited August 11, 2015 by Nick L

[legritter]

It will be the rain that will be the most notable over the coming days rather than thunder and lightning, although there should be a decent amount of that too. Localised flooding still remains the biggest threat.

 

S Midlands and SC England could see over 2 inches of rain quite widely over a 24 hour period.

Just what i was going to post ,seems like some very interesting days coming up ,well mother nature as been busy over parts of europe so is this the end result ,certainly not boring .

Tomorrows charts Data eagerly awaited ,lets hope we all get something .

[Pat Butcher]

Funny little setup for Thursday night into Friday morning. We've got reasonable non surface based CAPE but very little to suggest organisation - it more seems like pulse storms popping up across much of England over the course of the night with the potential for some chunky hail. Broadly, the severe risk is low, but some storm training, especially around the south coast, could turn really nasty despite being unlikely.

[Eskimo]

GFS 12z bring the deluge further east across Oxford & Reading, really worrying! 

[Eskimo]

80-110mm across the Oxford area come Friday night   

[Cableguy]

Eastbourne Airshow Thurs - Sunday, looks like it could be a washout, got to feel sorry for the organisers if it is.

[Rain123]

 Can never say for sure on times, or even they will happen, they could still easily miss us, but am about 70% confident

 

From all of what im seeing detail, I would say our best time would be Early hours Thursday probably between the hours 2am and 8am... On thursday looks a case of anything could pop up at  anytime

Cheers. Just I am going to the isle of wight tomorrow, for the day, and need to get back before the storms.

[Thunderbolt_]

I think Friday could be quite an interesting day in the sense that there isn't much CAPE available, yet we could still see a fair amount of thunder and lightning due to the sheer intensity of the rainfall. It could be something similar to what affected the south east on 24 July this year, just more widespread.

 

[Mokidugway]

Are we thinking there will be a slant wise convective event due to dynamic rainfall ?..

[NO LONGER POSTING]

Hmm... Chopping and changing begins