Harry

Awesome...everything about that picture strongly suggests to me that this is in fact a funnel cloud, not scud. Furthermore, from the middle picture it suggests to me that this 'scud' is forming in area of lowered cloud base, looking like a subtle wall cloud. If I was a betting man (which I'm not), I'd wager what you witnessed was a funnel all day long.

Sky is trying to brighten up here. If it is able too in the next hour or so we may be in some luck. Judging by the radar, rashes of heavy showers developing south of London. Given the motion of the precipitation, i.e comparing precipitation travel along the M4 corridor (due W) with the showers south of London (NNW) I'd be surprised if there's not, locally at least, more shear than perhaps anticipated.

Pouring down in London in the past 30 minutes or so and recently gone very dark. No sferics to speak of however. Lets hope once this clears through we may be able to develop some breaks for some good surface heating. To clarify my earlier post, I was referring to the idea that the amount of rainfall/rainfall rate/PWAT was linked to the probability of lightning. I think recent posts by Supacell and Weather09 deal with the issue beautifully - it is a lack of instability and wind shear (and therefore surface heating I would suggest) that has scuppered our lightning chances, not by virtue of relatively PWAT values. Take 3/4 July last year - if I recall correctly, we experienced exceedingly high PWAT levels, but also strong surface heating and very high (mid level in particular) instability. Added to this was a trough which helped destabilise the build up in instability.This resulted in very high lightning rates by UK standards. It is therefore more accurate to say, in my view, that the lack of lightning was not because of high PWAT levels/rainfall, but a lack of surface heating/wind shear and therefore lack of instability....broadly speaking. It is because of this I supported Surrey's appraisal of lightning risk today, but highlighting (rightly in my view) that because of an apparent repeat performance of yesterday (bucket loads of cloud cover) that we may see disappointing lightning occurrences today.

I am not entirely sure I can agree with the relationship between rainfall amounts and likelihood of lightning, William. Lightning occurs in volcanic eruptions and the last time I checked there is not a huge amount of rain involved there There is still a considerable amount of doubt within the meteorological community about what actually causes lightning. It seems incontrovertible that it is due to a build up of static charge. However, what is less clear is why in certain scenarios lightning occurs compared to others whereby it does not. You want a tall cloud, that reaches high up in the atmosphere (i.e where it is much colder and where you'll have a higher proportion of ice crystals/hail) and preferably violent updraughts and down-draughts to maximise the amount of particle collisions (i.e building up a much larger static charge).

Just started moderately raining here. Given the complete absence of any electrical action in some torrential downpours across the UK, I'm somewhat pessimistic about this rain turning thundery. On that note, good luck anyone staying awake and fingers crossed for tomorrow.

Worth noting that the mass of storms in the Med was not forecast by Estofex

On the plus side, sferic activity appears to be increasing quite rapidly across N France. On the down side, it is not sustaining for any lengthy period of time (i.e in terms of considering potential imported action) and, far more crucially on a NIMBY point of view, it is still unbearably miserable in my neck of the woods.

You're lucky - skies have remained leaden over London and continue to do so - mist, murk, yuck!! Realistically we need to hope that any storms that develop your way will then drift NW/W.

Not holding a great amount of hope for London and the SE at the moment. While it's still warm and muggy the cloud hasn't thinned in the slightest. Keeping my expectations at slightly above zero for the foreseeable future.

Thoroughly murky and damp here this morning. Muggy though. Looking at the satellite, it seems unlikely there'll be much brightness today, unless what is plaguing is at the moment is low cloud and it decides to lift.

Ahhh memories

Lovely!!!! That's what I like to hear! It's so warm and humid here, Windows will be wide open tonight (though may have to drown out road noise for GoT)

Sky to my south looks quite iffy and the humidity is high. However, given there have already been some heavy-ish falls already with no atmospheric pop I'm inclined to think instability is not quite there and some more robust forcing will be needed sooner rather than later for the SE.

I can only see towards the E/SE at the moment and looks very stable.

This model is being much more bullish regarding precipitation than the UKMO, which is much much more sporadic in terms of outbreaks (UKMO does hint however a isolated cell outbreaks ahead of lighter looking showery rain). NMM MUCAPE projections this evening aren't too inspiring (though there exists some). I therefore remain at a low end of the excitement scale...uplifted only by the fact it has been far warmer and sunnier than initially forecast and therefore hopeful Dan's forecast on UKCW may come to fruition (and in fact resembles much like the AROME model above)

Sun out in force in London at the moment

Not entirely sure I follow that either Ben...sounds like the presenter muddled their words a little lol.

On my walk to the station and skies looking distinctly thundery to my south. Dark complexion, hints of aspiratus undulatus together with bands of Ac (some of which is AcCas). You will all know the sort of sky I'm talking about. Touch more humidity in the air today too

I'm guessing that was a hail core not a wedge tornado?? Lol

A cats vs cucumbers video on YouTube?

A cap is basically a layer of air in the atmosphere that stops air rising (ie because it's warmer than the parcel of air rising from the ground). This is the simplest demonstration I've seen (and introduces Skew-T charts) https://m.facebook.com/notes/us-national-weather-service-little-rock-arkansas/what-is-a-capping-inversion-and-does-it-impact-our-weather/453868204689586/

Ukcw forecast out; Day 2 Convective Outlook VALID 06:00 UTC Mon 09 May 2016 - 05:59 UTC Tue 10 May 2016 ISSUED 20:39 UTC Sun 08 May 2016 ISSUED BY: Dan Large cut-off low will be located west of Iberia, providing a feed of of high WBPT air around its northern and eastern flanks across central/southern Britain. Assuming enough insolation occurs (questionable cloud cover) then pre-frontal troughing will be the main focus for deep convection, associated with a zone of low-level wind convergence providing the necessary forcing. Have issued a low-end SLGT to highlight areas of greatest interest, but even here it is uncertain as to how much lightning activity may actually materialise. High-res models also suggest a cluster of active thunderstorms moving N-wards from Brest peninsula towards the Channel Islands late Monday afternoon/early evening, hence the inclusion of a SLGT here. Showers/thunderstorms that do occur will move generally towards the WNW along this boundary. DLS is rather weak, and therefore limiting the overall severe risk, with the main threat being from minor surface water issues given potential for shower training over similar areas, especially farther west (i.e. towards Wales and Ireland).

That does look remarkably like a wall cloud there Galway

Concur there's some more instability showing now - initially this out to see in east Kent, now home in Bexley signs towards the west too. Very very warm here, car said 29C at one point, currently saying 27.5C and even if it's a degree off or so it is balmy for early May!

Well...just clapped my eyes on these off the Kent coast...now these are "towers" lol- and the sky is looking increasingly unstable further out to the east beyond these. Shame I'm not staying here on the coast this evening.