Convective/storm Discussion 5Th August >>

[Neilsouth]

Coast it wasn't just here that suffered , even most of france and the low countries. This front/trough really had a struggle to do anything bar a few strikes here and there , so all in all naff lol

[maidstone weather]

Coast it wasn't just here that suffered , even most of france and the low countries. This front/trough really had a struggle to do anything bar a few strikes here and there , so all in all naff lol

good - it's about time France and the Low Countries missed out!

In fact, despite the ESTOFEX Level 1, I wouldn't be surprised to see much of Belgium and western Holland miss out today

Edited August 7, 2009 by maidstone weather

[Coast]

One of the things that threw me was yesterdays 12Z sounding from Herstmonceux (or Herkymoo as it's known around here):

Now I still haven't got the full grasp of these, despite the excellent tutorials, but I do use this version as it highlights the important totals and their values, which can be broadly assessed by complete dunces like me for possibility and severity of storms. I concluded that although the CAPE was showing 452.78 (low) the Lift Index was -2.7 which is just getting toward moderate. Total-Totals, Showalter Stability Index, Thompson Index all seemed OK with a Bulk Richardson Number indicating multiple cells and this is for an area that was outside of the generally forecast TStorm possibility zone.

Again I acknowledge I have a long way to go with SkewT's but I do understand that they are very important to interpret correctly, together with other subtle atmospheric conditions and this is why I think a more scientific and experienced analysis of the numbers/charts and the forecasts from storm / aviation weather websites yesterday would help me see why it didn't meet my initial expectations.

I'll also go along with many on here that 'gut feeling' about temps and humidity suggested a good storm was imminent, even disinterested people here at work said they thought the day would end with one.

[dogs32]

The storms on the radar were so close to me yesterday! but as per usual they decided to skip by me to the East. Still a bit of August left yet and then there is always September for storms for Glos. (My storm matey dogs, promised me August and September is the time for us storm starved in Glos lol )

never fear Batman is here :lol:

It will happen,

Im nearly 100% confident as Glos as only missed one year without Storm's to my living memory.

That was yrs ago...So the possabilities of us getting nothing before Winter is slim.

But not impossible....dont forget what happened on Aug 16th?

Edited August 7, 2009 by dogs32

[chrisbell-nottheweatherman]

I too, would be interested to hear one of our top people explain what happened (or didn't happen). Also, I can't read skew-ts for love nor money, so any private message tutorial from Coast would be welcome, if that were possible.

As for here - looking back over the NW radar, we did get some rain, but it all seemed to fizzle. Much cooler here today, though it still feels humid.

[Coast]

any private message tutorial from Coast would be welcome, if that were possible.

:lol: Not me!!! You need clever people and my enthusiasm isn't sufficient I'm afraid. Homework for the class:

www.netweather.tv/forum/ a simple guide to understanding skew-t diagrams

www.atmos.millersville.edu

www.downunderchase.com(.pdf)

Now there will be test after the Summer Holidays and Principal Holmes and teachers Mr Nick and Mr Brick will be disappointed if we don't all get 100%!

Edited August 7, 2009 by Coast

[West Sussex Kate]

yep we had nothing in the night.

oh well I guess all isn't lost summers coming next week i've heard! (at last!)

[TEITS]

I personally wasn't disappointed because what I experienced is exactly what was forecasted.

Must admit I didn't follow the models or watch the BBC forecasts but I did read the Met O warnings. Now they warned of thundery rain and this is exactly what I got. During yesterday afternoon/evening I experienced spells of torrential rain which was accompanied at times with cracks of thunder. This for me is exactly what thundery rain is.

[Tom Montalbano]

I, like a lot of members on this thread, was very surprised by the lack of thunder reported last night. I fully expected embedded storms to spring up, especially as last nights ppn started to encroach into the very humid air over some parts of S.E, E.England and E.Anglia. but then again in 40 odd years of having an interest in meteorology have found forecasting thunder is as difficult as forecasting snow in the B.Isles. Both theses elements behave in a very fickle way in our neck of the woods.

I tend to agree somewhat with Harrys observation, which I think he also mentioned a few weeks ago, along with myself, that when you have high pressure beginning to nose into N.W.France it tends to restrict the possibility of a more violent breakdown. I would suggest that the synoptics prevent the more explosive convection we tend to get when a more defined area of low pressure nudges up from N.France.

I would like to hear the views of the more technically minded NW members, as Coast has suggested, as to why last night ended with a damp squib, albeit a very wet one in some areas.

I'll leave you with the synoptic set-up for 28 years ago, 6th August 1981, as it has been mentioned in the last few days.

Certainly one of the most thundery breakdowns I've experienced in the S.E.London area, when the sky turned pitch black twice in the space of a few hours, mid-morning and again around noon, accompanied by very frequent lightning and explosive thunder.

http://www.wetterzentrale.de/pics/archive/ra/1981/Rrea00119810806.gif

http://www.wetterzentrale.de/pics/archive/ra/1981/Rrea00219810806.gif

Regards,

Tom.

[Coast]

Perhaps the problem is interpretation and reliance on information from other websites and sources + too much expectation and too little experience? (mea culpa!) :lol:

Certainly Netweather had no convective forecast out, not sure if that's because of the holidays or it wasn't perceived to be a necessary. ESTOFEX are quite respected and I find the UKASF site and their analysis is usually pretty good. TORRO had nothing, but that can often be the case - I think that has to do with staffing as well.

Lumping that in with some aviation weather forecasts (all seemed to point towards CB's and storms) together with USAF warnings + a sprinkling of GFS models, I thought that something would have transpired. I guess my fervour for a storm fuelled by a few charts in the lead up to yesterday, clouded sensible judgement and a recent distrust of MetO 'public' forecasts has proved me wrong!

Back to the drawing board, down but not out!!!!

[chrisbell-nottheweatherman]

Well, Coast, I've followed the links you provided, and I think I'm getting the gist of it. :lol:

[Coast]

Well, Coast, I've followed the links you provided, and I think I'm getting the gist of it. :lol:

Great!!

Now can you let me know?

[chrisbell-nottheweatherman]

Great!!

Now can you let me know? :lol:

Starting to get the gist, mate - not exactly expert!

[Noctilucid]

Thanks a lot Coast, I've been trying to find that downunder chase article again for years!

[maidstone weather]

In fact, despite the ESTOFEX Level 1, I wouldn't be surprised to see much of Belgium and western Holland miss out today

[maidstone weather]

Hmm, seems Belgium and the Netherlands have had storms. That will be the high CAPE values and steep lapses then.

only the extreme east of Belgium and C + E Holland have seen storms, as I said this morning most of Belgium and western Holland will miss out and indeed they have. Very fickle weather at the moment

[Harry]

Have still seen storms though regardless. The fact that they were confined to the extreme E of Belgium and Central and Eern Hollands may be down to wind direction (well, the movement of the front) and when maximum CAPE was realised. But nevertheless, they have had a good few storms, and it just so happens that there is nice pool of CAPE and some cooler air aloft to help promote convection. Something which yesterday had little of for the Sern and Eern half of the UK.

To my SSE, in hazy skies, there seems to be a towering Cu! I'll be honest I can't see much of the sky in that direction due to the haze and other clouds, but it does look like the edge of a robust Cu...radar seems to show something, but that's also the area of the map where anaprop is rife.

Just an observation anyway

[maidstone weather]

To my SSE, in hazy skies, there seems to be a towering Cu! I'll be honest I can't see much of the sky in that direction due to the haze and other clouds, but it does look like the edge of a robust Cu...radar seems to show something, but that's also the area of the map where anaprop is rife.

Just an observation anyway

there was me gawping at the intense echoes over Ireland!

I see the far north of Scotland has already had thunder and lightning this afternoon. We had a rather dark cloud base to my southeast for most of the afternoon but now it's brightened up a bit. Looking at Sat24 looks like patchy cumulus are converging? (ie moving in from the east and in from the west pretty much over London)

[Upgrade]

it has gone very heavy here and there are funny gusty winds. i think there is a small storm or heavy convective shower nearby .

[maidstone weather]

it has gone very heavy here and there are funny gusty winds. i think there is a small storm or heavy convective shower nearby .

There's this little potent cell on the radar

[MAF]

it has gone very heavy here and there are funny gusty winds. i think there is a small storm or heavy convective shower nearby .

was thinking when i left home (woolwich) to come to work tonight (whitehall) that we could be in for a sharp shower. the clouds looked very threatening and temps still quite high

[Tommyboy2007]

I can see the remnants of the potent little cell from here in Horsham (RH12) It looks to be the only significant shower in the southeast.

You cn see it's development on Sat24 satelllite loop. Interesting !

[Upgrade]

I can see the remnants of the potent little cell from here in Horsham (RH12) It looks to be the only significant shower in the southeast.

You cn see it's development on Sat24 satelllite loop. Interesting !

poor little thing stuck there on its own ! where's it headed... presume its decaying now.

[Chloe]

Gone vey heavy here been like it since 19.oopm nothing coming off it just hanging, seems to be coming in from the North East anyone else notice this??? strange that nothing has happened, especially over Hanger Lane/ Shepherds Bush way

[Harry]

Bit far off, but this ECMWF chart looks quite promising to me.

GFS not suggesting much though - but always nice to see T (or L ) to the West, H to the East with a warm pool of air coming up from the S/SW. This chart isn't ideal at the moment for what we all are looking for, but it's not too bad at this stage