Convective Discussion

[Harry]

Precisely MW/Blizzards

Our last hot and humid spell ended with a bit of rain - this looks like going exactly the same way.

Like on this year's Aug 6th, the temperature differences across the country are going to be quite stark. These are the temp forecasts just for England and Wales on Weds and Thurs from the MetO:

London: 29-30C (Weds) and 26-27C (Thurs)

Cardiff: 20-21C (Weds) and 18-19C (Thurs)

Manchester: 19-20C (Weds) and 17-18C (Thurs)

I was a little bit perplexed with the lack of stormy conditions last time round, I think I might equally be this time.

Edited August 17, 2009 by Harry

[Coast]

I was a little bit perplexed with the lack of stormy conditions last time round, I think I might equally be this time.

I blame it on the recession - and electricity prices. Well a storm requires a lot of energy and it ain't cheap you know!!

[Harry]

I blame it on the recession - and electricity prices. Well a storm requires a lot of energy and it ain't cheap you know!!

No it's not, you're spot on there, lol!

Just to fuel the debate on climate change, I've been occasionally (when bored) looking back on youtube at some of the forecasts from the early 90s...and comparing them to those of today (not layout, but the statistics)...you cannot but help notice the difference, it is staggering - notably the winter forecasts!! One Ian McGaskill 1992 winter forecast - daytime temperatures everywhere of no higher than -5, with a windchill in the SE of -16! 4 consecutive days of heavy snowfall...par exemple!

Global warming, greenhouses gases, call it what you will - the climate is without a doubt changing significantly...thunderstorms are just one of the casualties IMO (even though we had a good June/July, I'm getting an irritating thirst again lol)

[Methuselah]

Global warming, greenhouses gases, call it what you will - the climate is without a doubt changing significantly...thunderstorms are just one of the casualties IMO (even though we had a good June/July, I'm getting an irritating thirst again lol)

Oh, I don't know Harry? We've had lots of thunder this summer...

Well for Thursday, Scotland looks favourable for storms or, showers with 'the odd rumble of thunder'

See what I mean, Harry? <_<

[Nick F]

UKMO seems more bullish with a thundery breakdown Thurs than GFS, just looked at the aviation 3 dayer and it mentions locally heavy rain with slight risk of embedded thunderstorms moving E during Thurs with risk of isolated heavy showers or thunderstorms in SE later. Though I would be cautious of any forecast this far off.

August has turned out rather poor so far for storms, so hoping the brief hot spell doesn't go out with a whimper aka GFS!!

[maidstone weather]

a classic surface LOW develops over NE France Weds evening:

http://212.100.247.145/fax/PPVK89.png

shame that trough is too far east!

Bear in mind, August 6th 2008 was also a Wednesday night

(Some similarities: http://www.wetterzentrale.de/archive/2008/brack/bracka20080807.gif )

Edited August 17, 2009 by maidstone weather

[Coast]

UKMO seems more bullish with a thundery breakdown Thurs than GFS, just looked at the aviation 3 dayer and it mentions locally heavy rain with slight risk of embedded thunderstorms moving E during Thurs with risk of isolated heavy showers or thunderstorms in SE later. Though I would be cautious of any forecast this far off.

Welcome back Nick and thanks for the analysis (we've needed your approach to forecasting storms here the last couple of weeks! )

August has turned out rather poor so far for storms, so hoping the brief hot spell doesn't go out with a whimper aka GFS!!

Any idea why this year has been a particularly damp squib for us storm lovers?

Edited August 17, 2009 by Coast

[NL]

Welcome back Nick and thanks for the analysis (we've needed your approach to forecasting storms here the last couple of weeks! )

Any idea why this year has been a particularly damp squib for us storm lovers?

I agree with Pete Tattum that storms have been a bit more frequent in Scotland and we have favoured quite well in the NE too although not particulary 'strong' storms but storms nonetheless and as i type there is a large anvil to my WNW i dont think any Sferics have been detected but at looks to have potential.

[maidstone weather]

I agree with Pete Tattum that storms have been a bit more frequent in Scotland and we have favoured quite well in the NE too although not particulary 'strong' storms but storms nonetheless and as i type there is a large anvil to my WNW i dont think any Sferics have been detected but at looks to have potential.

I'd agree with that too (and not just because I live in a storm-starved corner of the UK )

I also feel the Midlands peaked too soon - they had storms a-plenty in Spring, but seems to have quietened there in the past 6 weeks or so. Quite the opposite of last year if I remember, where parts of the West Midlands did poorly until mid-July onwards. That's what you get with the great British weather

[Coast]

What do we think has caused the relative quiet from the Midlands downward? Jet position? the Atlantic? The Channel? The Met Office? (they get the blame for everything weather related this year!!)

[Harry]

What do we think has caused the relative quiet from the Midlands downward? Jet position? the Atlantic? The Channel? The Met Office? (they get the blame for everything weather related this year!!)

I am not sure we can say from the Midlands southward...I saw two "storms" in April, none in May, then 18 across June and July. So far, August has produced nothing.

It very much depends on where you are...E Kent has done well as ever, NW Kent (my area) hasn't done too bad either. S and C Kent however has had a mare of a year...this is all within ONE county, let alone region!!

Those charts seem to favour E Kent again, though margin for change certainly in the coming days, especially with an incoming trough on thursday!!

[Noctilucid]

Odd that here in East London we've had a very thundery summer, early summer had some home grown storms with very powerful and frequent lightning, imports have been fairly weak this year and we've had a few rather weak storms in between, but a lot more storms than 07 or 08.

Been rather quiet recently though.

Edited August 17, 2009 by jshaw

[Harry]

Odd that here in East London we've had a very thundery summer, early summer had some home grown storms with very powerful and frequent lightning, imports have been fairly weak this year and we've had a few rather weak storms in between, but a lot more storms than 07 or 08.

Been rather quiet recently though.

A much more extensive, and significant build up of CAPE/LI over N France in this latest run.

Storm risk still keeps it sliding across the continent, and maybe at best brushing SE Kent.

Makes me wonder though - has it picked up on the potential for a surface low to develop, as the latest FAX chart suggests? I would have thought a more extensive storm risk across N France if a surface low were to develop, with rather decent CAPE/LI?? Temps across France are expected to rise to the mid 30s at this stage!

Overall - at this stage, I am far from optimistic. Until it really starts warming up tomorrow and into Wednesday, the excitement level will remain at 0!

[Costa Del Fal]

No storms here since the end of june/very begining of July. Certainly due one now but my optimism isnt high.

[Costa Del Fal]

No proper storm here since Apr 15th. Would say I'm due one soon, but that's not how Mother Nature rolls Can't just 'expect' and get what you want

I sympathise and say you Need a storm URGENTLY!

Looks like 29th June storm will be my best one of the year which i have to say was pretty dangerous in its core-especially the rain. Time is running out fast but September could still deliver something but with the weather like we have now it could remain pretty boring but its still better than endless rain!

[Thundery wintry showers]

what is going wrong? To reach 30+C on Wednesday, only to turn cooler on Thursday thanks to a bit of rain - something seriously wrong with this setup which is preventing big storms with conditions like that?

No doubt a couple of sleepless nights this week

I think the main reason for this is that the Atlantic system is set to push eastwards quite quickly, limiting the amount of time for both continental imports and homegrown shower activity to coincide with the cold front. Most thundery breakdowns from the west (at least from my experience of observing during the last 16 years) involve a slow moving front, organised areas of heavy shower/thunder activity rumbling northwards along the front and/or heavy thundery showers breaking out to the east of the front.

It's similar to why so many of those rapid frontal breakdowns of winter cold snaps generally fail to deliver much snow. The Atlantic air comes rushing in straightaway, as opposed to when we have slow moving fronts and rain belts stalling against continental/arctic air and turning to snow.

I agree with Pete Tattum that storms have been a bit more frequent in Scotland and we have favoured quite well in the NE too although not particulary 'strong' storms but storms nonetheless and as i type there is a large anvil to my WNW i dont think any Sferics have been detected but at looks to have potential.

I reckon July 2009 in Tyneside probably had the highest number of individual days with thunder activity in a calendar month since June 1980. I received reports of thunder from South Shields and/or Cleadon on 7 days, which is equal to the 1993-2008 annual average!

[dogs32]

dont think it's been a poor year for some like the N/E or part's of the South East.

Like someone said depend's on where you live..

Glos is in the procces of being the most Storm free for year's.

[ANYWEATHER]

dont think it's been a poor year for some like the N/E or part's of the South East.

Like someone said depend's on where you live..

Glos is in the procces of being the most Storm free for year's.

eeerrhhh put Worcestershire in with that pat!

[maidstone weather]

Weds night trough removed - but replaced on Thursday!

http://212.100.247.145/fax/PPVK89.png

*Keeping calm*

[dogs32]

eeerrhhh put Worcestershire in with that pat!

lol..Ok that place as well mate....Also I think Bekka hasnt seen a Storm,

MD I did think it was for THursday anyway....To be honest Im not getting any hopes up...past waiting

If anything does try to produce it doesn't look like anything great at present

[Harry]

I think the main reason for this is that the Atlantic system is set to push eastwards quite quickly, limiting the amount of time for both continental imports and homegrown shower activity to coincide with the cold front. Most thundery breakdowns from the west (at least from my experience of observing during the last 16 years) involve a slow moving front, organised areas of heavy shower/thunder activity rumbling northwards along the front and/or heavy thundery showers breaking out to the east of the front.

It's similar to why so many of those rapid frontal breakdowns of winter cold snaps generally fail to deliver much snow. The Atlantic air comes rushing in straightaway, as opposed to when we have slow moving fronts and rain belts stalling against continental/arctic air and turning to snow.

I reckon July 2009 in Tyneside probably had the highest number of individual days with thunder activity in a calendar month since June 1980. I received reports of thunder from South Shields and/or Cleadon on 7 days, which is equal to the 1993-2008 annual average!

Hmm...that would make some sense, however Aug 6th, the high temperatures were around for a few days, along with very high humidity. The front couldn't have gone any slower if it tried lol. From some of what I was reading, the hot and humid air present over the SE stagnated and became more stable. Despite there being fields of Ac, and some Acas representing some instability at mid altitudes, there was no sudden 'boom', or sudden uplift, creating the big Cbs required for T and L. This happened around Oxfordshire, but seemingly very few other places, especially the hottest and more humid places

On this occasion however, because of the hot and humid air coming in only for a brief amount of time, I am hoping that this will mean the air at higher altitudes will not have to time to warm up. This, in my head anyway should mean a decent temperature gradient is maintained, greater instability, and greater potential for boom when the front moves in!

Problem there seems to be at the moment, is that because the hot and humid air comes in for such a brief period of time, CAPE does not have time to build sufficiently. Before, there seemed to be too great a time, therefore stagnation - on this occasion, there seems to be not enough time....oh as usual I dont know, lol...seems to make some sense in my little head, but don't overly know.

I am sure we'll get a better idea nearer the time when the charts start to yield more up to date info.

[pottyprof]

Well....... BBC went for thunderstorms for later in the week on the 10:30pm forecast.. No guesses as to where they will be tho..

[A.J]

Hmm...that would make some sense, however Aug 6th, the high temperatures were around for a few days, along with very high humidity. The front couldn't have gone any slower if it tried lol. From some of what I was reading, the hot and humid air present over the SE stagnated and became more stable. Despite there being fields of Ac, and some Acas representing some instability at mid altitudes, there was no sudden 'boom', or sudden uplift, creating the big Cbs required for T and L. This happened around Oxfordshire, but seemingly very few other places, especially the hottest and more humid places

On this occasion however, because of the hot and humid air coming in only for a brief amount of time, I am hoping that this will mean the air at higher altitudes will not have to time to warm up. This, in my head anyway should mean a decent temperature gradient is maintained, greater instability, and greater potential for boom when the front moves in!

Problem there seems to be at the moment, is that because the hot and humid air comes in for such a brief period of time, CAPE does not have time to build sufficiently. Before, there seemed to be too great a time, therefore stagnation - on this occasion, there seems to be not enough time....oh as usual I dont know, lol...seems to make some sense in my little head, but don't overly know.

I am sure we'll get a better idea nearer the time when the charts start to yield more up to date info.

Good post Harry, makes a lot of sense to me

[Neilsouth]

Did you see those storms exploding over eastern europe? , WOW must've been intense!. Would like that

[Coast]

Ferry or tunnel tomorrow then?

and the same to Zeebrugge on Thursday?

But how about staying home Friday?