El Gordo! - Spanish Plume Thunderstorm Discussion 3

[DanN]

Can someone more knowledgeable of storms than me explain how a cape of 2600 and a lifted index of -8 in 30c heat can only produce a light shower? I would have expected fireworks with conditions like that!

You still need a trigger to release that energy or it all gets wasted. Looking at the radar you probably have some of the remains of that MCS nearby.

[Neilsouth]

hmmm

Edited June 27, 2011 by Victor Meldrew

[Grazy2266]

Rather warm here in Bucks 31.6°C currently, a layer of high cloud is fast approaching from the west (a light shower is expected from this in the next hour), so conditions can be best described as "milky" at the moment. Keeping an eye on developments to the south-west, keeping a keen on on what's coming up from the channel too, in terms of precipitation.

Edited June 27, 2011 by buckslad28

[seabreeze86]

cloud begining to bubble up here now i dont think it will be long before the showers get going up here, they wont be as severe as on the south east later but i will settle for just a few flashes

[Harry]

Can someone more knowledgeable of storms than me explain how a cape of 2600 and a lifted index of -8 in 30c heat can only produce a light shower? I would have expected fireworks with conditions like that!

In order such potential to be 'let loose', the cap needs to break, which is the layer of dry air sitting comfortably above the unstable air.

Smaller showers can build under the cap, bring precipitation. The 2600 CAPE and -8 LI however is, effectively, above the cap and will only be released if the cap goes - this can be done through a trough, CF, CZ or intense heating.

For your area, it's very touch and go whether that energy will be released in the form of storms or not. The CIN (which is for all intents and purposes the 'cap', otherwise called 'Convective Inhibition' or CAPE's evil twin) is too high at the moment.

[Coast]

Good old Gravesend officially highest currently with 30.9 DgC http://www.metoffice.gov.uk/weather/uk/observations/

[Harry]

Good old Gravesend officially highest currently with 30.9 DgC http://www.metoffice.gov.uk/weather/uk/observations/

That was at 1300...curious to know what 1400 will read

[TEITS]

I feel some are being impatient. For the SE/E Anglia/E Midlands it isn't supposed to kick off until this evening and in some parts late evening/overnight.

[dave reid]

Im no expert but , Even with a such high cape and lifted index if the air is capped (warm dry air above the good / energy filled air) then the Cu clouds cant grow that big as they are stopped when reaching this cap of warm air. As the day goes on this cap can be erroded or the surface heating will cause the rising air to over come it.

Again no expert but general jist

just seen you question has already been answered

Edited June 27, 2011 by dave reid

[Harry]

Im no expert but , Even with a such high cape and lifted index if the air is capped (warm dry air above the good / energy filled air) then the Cu clouds cant grow that big as they are stopped when reaching this cap of warm air. As the day goes on this cap can be erroded or the surface heating will cause the rising air to over come it.

Again no expert but general jist

just seen you question has already been answered

Pretty nailed on summary!

IF the cap were to break somewhere in the Midlands/EA/NE, then be prepared for putting in some insurance claims as it could be mega!! lol

[chionomaniac]

I feel some are being impatient. For the SE/E Anglia/E Midlands it isn't supposed to kick off until this evening and in some parts late evening/overnight.

Yes one of those days. Will the cap be broken? It may take half a degree more than achieved!

[Thundery Shower]

i have my eye on the cells just leaving NW edge of the bay of biscay, just ahead of the trough moving N/NE

[scotteboi]

Convective Inhibition (a "cap" basically) can prevent storms initiating on days such as today

I take it that the anticipation is that there will be a break in the CAP? I am quite new to this so please forgive my ingnorance

[Purplepixii]

temperature here in Fareham now down to 23.3 with 67% humidity, temperature slowly increasing again, overcast with a few spots of rain 20 minutes ago

Edited June 27, 2011 by Purplepixii

[DanN]

I feel some are being impatient. For the SE/E Anglia/E Midlands it isn't supposed to kick off until this evening and in some parts late evening/overnight.

I may be one of those! At the moment I can't see what might initiate anything home grown, cold front is out west with no sign of the trough that was discussed this morning. I know its still early but the south has looked pretty capped on all recent model runs as well. Are we just looking at that French MCS you think? Which seems to have decreased in lightning activity recently - if the sat loops are correct.

Edit: Apart from that MCS, France appears to be looking at clear skies!

Edited June 27, 2011 by danuk

[sunny scunny]

31.1C here in South yorks. Paul Hudson recons a 33c will be reached around the donny / finningley area.

Could get even higher.32c here but cloudy and rather breezy.

[fromey]

afternoon all.

well after the rain temp 23.7 pressure 1001, humidity 37%

chances of a storm or 2, 15% 20% at best.

i wish i was in the SE right now

fromey.

Edited June 27, 2011 by fromey

[andy_leics22]

Thanks for the replys peeps You'd have thought after 7 years on the site I would have learned that about thunderstorms but i've always been a lot more interested in that special event that begins with an S and ends in a W

[Joneseye]

I take it that the anticipation is that there will be a break in the CAP? I am quite new to this so please forgive my ingnorance

I think that is why many people were disappointed with the layer of Cirrus that came across some parts this morning as part of the remnants of that MCS. Had it not been cloudy it may have given more area's a chance of getting enough heat to break the CAP.

BTW sea breezes can help to form convergence zones to break the CAP also.

[SnowJoke]

Still overcast here with a high cirrus layer, but signs of mid level activity starting. There's a lot of lower cumulus forming, some quite large with darkening bases in areas. It feels and looks very stormy now, a day where one minute there is nothing then all hell brakes loose.

[Mesoscale]

0%! All that potential aswell, come on MCS do your thing! come on CAP break!

Edited June 27, 2011 by Mesoscale

[Biggin]

I presume that the CF is expected hoped to be the trigger to break the CAP in SE?? am I right??

[Gorky]

Can someone more knowledgeable of storms than me explain how a cape of 2600 and a lifted index of -8 in 30c heat can only produce a light shower? I would have expected fireworks with conditions like that!

I'd imagine there is a capping inversion preventing convection from getting too robust at the moment. With daytime heating and increasing instability it's quite possible that convection will break through this layer and we'll get thunderstorms. I've seen days pushing 9000 CAPE in the US not break through a cap before though Forcing is pretty weak down south so it's no guarantee we'll see widespread storms. However, there is a good 3 hours+ til peak heating to go. It's pretty rare even in the US to get events where the entire warm sector starts to light up. More often than not, storms form on the warm front, cold front and dryline and move off from there into the warm sector.

Edit: Shoulda guessed I'd be beaten by about half a dozen people the rate this thread is going!

Edited June 27, 2011 by Gorky

[seabreeze86]

The odd shower now forming in northen england and intensifiying rapidly hope this could be the start of a interesting afternoon

[scotteboi]

I think that is why many people were disappointed with the layer of Cirrus that came across some parts this morning as part of the remnants of that MCS. Had it not been cloudy it may have given more area's a chance of getting enough heat to break the CAP.

BTW sea breezes can help to form convergence zones to break the CAP also.

Cheers, cloudied over in braintree at the moment but still hot and sultry out there