Uk Convective General Discussion & Forecasts, 17th July 2012>

[Harry]

Indeed. This is why I just couldn't bring myself to go into detail as to why I disagreed with Harry's comments in response to mine re. June 28th's severe convective episode.

The funny part of the reply is where he says that no individual storm that developed on June 28th could "compete" with an MCS (whether it developed over France, or wherever, is irrelevent) in terms of scale or electrical output.

Well of course they couldn't! An MCS, by definition, is a complex of thunderstorms which have become organised as a result of a favourable vertical wind shear environment. So, effectively what he is saying is that no one storm on June 28th could compete with several seperate cells which form an MCS, each discharging frequent lightning strokes.

But what am I talking about, there were two MCSs that day - one over the West Midlands, the other which blitzed NE England. So, er, what's his point?

Not to put too fine a point on it........Yaaaaaaaaaaaaaaaaaaawn!!!

It sunny, warming up, summer has arrived!!!

Edited July 22, 2012 by Harry

[mattyk1985]

Potential pretty much looking non existent compared to what It was showing. Its still early and lots of swapping and changing is to be expected.

[Mapantz]

I also picked up on this a few days ago .. I asked Ian Fergusson for his thoughts; UKMO currently consider GFS v cyclonic prog "....a lower probability alternative (to less unsettled), but not insignificant"

A case of waiting a few more days, i would say.

[East_England_Stormchaser91]

Lets narrow things down ere lads, June 28th 2012 was all about the high levels of shear, giving the very large hail and gusty tornadic winds. June 28th 2005 was all about the very high levels of convection over a scorched continent which lead to the fantastic night lightning displays. Either way 28th of June has to go down as one of the stormiest dates of my lifetime so far, as I may be correct in saying 28th June last year even brought some tail end French import storms to the E of England which gave some deafening thunder too! Will be interesting what 28th June 2013 has to offer !

[East_England_Stormchaser91]

Potential pretty much looking non existent compared to what It was showing. Its still early and lots of swapping and changing is to be expected.

I really hope just for once we get a direct hit from this. Knowing these days though, It'll be just too good to be true and we'll be left with nothing but a boring, irritating and frustrating Northerly wind! As you say though, things can change a lot in these situations. We can only pray!

[legritter]

still loking good in my opinion for after about wednesday .the potential is still good but remember we are talking a very large area in square miles especially at this time range .many ingrediants will be in place but its the final one that will bring the end result .in my opinion looking at all the charts and data currently available and reading between the lines and a bit of experience i will stick my head out and say ,late wed to about following late monday [very active weather about ,but locations will be hard to pin down as although the weather will be in some locations bad it wont be moving very fast ,and the possible disruption of summer events , dont forget even 10mm of rain during olympics will be classed by some media reporters as dire ] tomorrows charts and met fax very important as todays forecasts [sunday]will probably not mention much of olympics ,bbc week ahead etc ,wait untill later tomorrow as they will have to commit themselves ,and then its only 90 odd hrs away ,enjoy the heetwave while we have it cheers legritter

[legritter]

help where are you all ,hopefully enjoying our summer . HEAT BUILDING ,BECOMING HUMID BY WED ,TEMP IN SOME PARTS REACING 30 C ,EVEN HOTTER ON CONTINENT ,LOW PRESSURE MOVING UP FROM FRANCE ,COLD AIR ALOFT MOVING DOWN FROM NORTH , OFFICIALS AT OLYMPICS GETTING CONCERNED , seriousely ,hope the oly go well , come on gang im starting to have conversations with myself concerning the potential on offer ,i would like some input from other posters with their views , its all 4/5 days away and things can change but it does look like a change and what are your views from your location ,cheers legritter

[Azores Hi]

Stuff the Olympics! I'm hosting a BBQ for 80 people on Saturday! Looking like a washout at the moment...

[legritter]

hope your bbq goes well sat AZORES HI . i like kent ,spent some time at DEAL back in late 60s early 70s in RM . can remember standing out on parade in freezing temperatures ,that sure is a cold wind of the continent . perhaps anything too severe will be gone come sat ,and you will have a dry slot .before anything else turns up . but keep an eye on those french with their imports ,cheers

[Coast]

So what do we make of this from GFS for Friday afternoon in Southern England then?

Yee haw indeed!!!

[legritter]

some good charts and information now coming in from posters ,cheers COAST , im back to garden now to tidy up the borders and prepare viewing platform ready for fridays show , im ready for those french imports ,just hope they shuv em far enough west ,heres to all the other posters in antisipation of more info ,wonder who and what country will get the possible electrical supply difficulties fri sat ,in regards storms ,some dissapointed olympic viewing could be affected ,lets hope everything goes ok for the opening cheers

[Chris K]

It's still early to say obviously. But does the spread of potential storms depend heavily on how fast the low from the NW moves down from Iceland?

I.e - if it were to move down slower than currently shown on models, would this result in storms perhaps being more widespread across the South?

Currently the thundery low forecast to develop and move N/NE looks to probably move too far East from us as it gets pushed away fairly quickly. Perhaps the SE having the highest chance of witnessing anything that does drift up?

[NL]

Very small chance of storms developing here in the NE (again) tomorrow with CAPE values 300-400J/Kg and Li's around -1, temperatures low to mid twenties and dew point in the mid to high teens. Best potential around East Yorkshire. To early to mention the south's chances come the end of the week but potentially some potent storms could meander their way from France. Hope you people in the south get a humongous MCS the likes only witnessed every 50 year..!

[Keraunic]

Anything in the offing for EA, particularly Ipswich area? I want a humungous MCS on a biblical scale. :o

[Gavin P]

Here's today's video examining the possibility of thunderstorms Friday into Saturday;

http://gavsweathervids.com/

As ever the risk of thunder in the UK is uncertain, but the threat is there.

Edited July 23, 2012 by Gavin P

[legritter]

just had alook at charts and data again ,and yes at this stage it could be hit or miss for many .but still the potential is there . we will know much more come wednesday , keeping an eye on developements on met site as they will only post under current events when they are more confident , as they would not want egg on face ,especially this week .

[Harry]

Very small chance of storms developing here in the NE (again) tomorrow with CAPE values 300-400J/Kg and Li's around -1, temperatures low to mid twenties and dew point in the mid to high teens. Best potential around East Yorkshire. To early to mention the south's chances come the end of the week but potentially some potent storms could meander their way from France. Hope you people in the south get a humongous MCS the likes only witnessed every 50 year..!

Well, I have it on very sound authority that the boundary layer so on and so forth is not conducive for big storms, certainly not on the scale that was witnessed on the 28th June. The MCS looking feature depicted on GFS is an anomaly because there is insufficient shear to support any organised convective events. God has already decreed this so I am not getting my hopes up a jot.

Beautiful day here though...absolutely STUNNING!!! Shame I'm back in the office, but I've got a long weekend starting Friday....I wish I could be looking forward to

Edited July 23, 2012 by Harry

[Harry]

So what do we make of this from GFS for Friday afternoon in Southern England then?

Yee haw indeed!!!

I've got Friday to Monday off this coming weekend...if it's looking remotely optimistic we'll be couriering our backsides down to Dymchurch a bit lively.

I'll take some light displays from the coast if nothing else is on offer.

[East_England_Stormchaser91]

All will be decided on where that irritating cold low off Iceland will end up, the further away it stays, the greater chance of some wicked storms in the South especially, but even further North too.

[Coast]

I'll take some light displays from the coast if nothing else is on offer.

OK, I know this is out in FI a bit in terms of convective weather and storms and forgive me, but we wouldn't want to be just looking at what is happening on the radar right now, every day would we?

So if I overuse words like potentially, possibly and fingers crossed this week, it's just me tempering my enthusiasm!

I'm quite pleased to see potential from early in the morning right through into the darker hours as if we are in luck, it could provide a nice show for a few people. With the weather as crazy as it has been this year, I'm not sure what to expect but in days gone by, we could often see a thundery breakdown after a nice warm spell (see, being cautious here!). I'll bank the GFS general outlook at this stage and look for signs and trends amongst the ups and downs of the next few days, that we may get a good lightning display!

[Harry]

OK, I know this is out in FI a bit in terms of convective weather and storms and forgive me, but we wouldn't want to be just looking at what is happening on the radar right now, every day would we?

So if I overuse words like potentially, possibly and fingers crossed this week, it's just me tempering my enthusiasm!

I'm quite pleased to see potential from early in the morning right through into the darker hours as if we are in luck, it could provide a nice show for a few people. With the weather as crazy as it has been this year, I'm not sure what to expect but in days gone by, we could often see a thundery breakdown after a nice warm spell (see, being cautious here!). I'll bank the GFS general outlook at this stage and look for signs and trends amongst the ups and downs of the next few days, that we may get a good lightning display!

Oh no I couldnt agree more Coast...my comment was more a dig at the inevitable eastern shift for anything which might develop over the continent.

I'm expecting nothing, well, until I see Wednesdays/Thursdays charts and if its still looking good for storms in the region then I might get a wee bit more anticipatory.

Edited July 23, 2012 by Harry

[Coast]

my comment was more a dig at the inevitable eastern shift for anything which might develop over the continent.

Damn those pesky shifts over there!!!! All the lovely charts and meaty radar returns can turn to nowt if the Channel is feeling fickle. I wouldn't put it passed those Frenchies to send them somewhere else, after Bradley took they're big cup away yesterday!!!!

[Nick F]

Certainly some uncertainties later this week re: a thundery breakdown. Other than some isolated thundery showers/storms near the CF over central areas on Thursday, Friday *may* have some potential. A moistening airmass across England and Wales *may* destabilise ahead of the CF moving SE - as per GFS - which brings a thundery low up from the SW ahead of the cold front shifting SE across England later in the day - which looks to push the heat away by Saturday.

All depends on how quickly the upper trough moves SE. ECM and UKMO more progressive with the trough and seem to nudge the thundery low further east than GFS at this point - with the near continent stealing the fun from the SE, though some thundery rain/storms shown near the CF for central parts.

[mattyk1985]

Certainly some uncertainties later this re: a thundery breakdown. Other than some isolated thundery showers/storms near the CF over central areas on Thursday, Friday *may* have some potential. A moistening airmass across England and Wales *may* destabilise ahead of the CF moving SE - as per GFS - which brings a thundery low up from the SW ahead of the cold front shifting SE across England later in the day - which looks to push the heat away by Saturday.

All depends on how quickly the upper trough moves SE. ECM and UKMO more progressive with the trough and seem to nudge the thundery low further east than GFS at this point - with the near continent stealing the fun from the SE, though some thundery rain/storms shown near the CF for central parts.

Im no expert but looking at the latest run it appears that the GFS is starting to side with the ECM and UKMO.

[Supacell]

If anything, the 12z GFS shows the better chance being across the Midlands on Friday with the continental imports being taken across Holland.

Maybe a chance of something across NW England, Wales and W Midlands on Thursday too, with the very slightest risk that something could flirt with this area.