Storm/convective Discussion

[Shiny_Bottom_1]

Humidty seems very low here, with cloudy skies and a nice little breeze.

Actually feeling quite fresh this morning.

Central weather forecast goes for T-Storms in the southern and central part of the midlands, but forecast for sunny spells (and no t-storms by the afternoon) for the northern part of the midlands (i.e. about Tamworth northwards).

NW forecast going for an increasing chance of t-storms throught the day.

Would be nice to get something at some point, but chances look a little slim at the mo.

[philglossop]

Nothing down here again, it did cloud over around 730pm last evening, but then cleared by 10pm. Not looking good for today here either. I'm off to the no storms thread!

[Neilsouth]

As i said before when the met office make a bad forecast i slate them , make a good one and i praise them... The forecast from yesterday for last night was spot on for this corner of kent , we didn't get any storms and it remained calm and humid all night. Well done met office :lol:

[Supacell]

Was thinking of going on a chase after work but I am concerned at the BBC forecasts who seem to show it all dying out after about tea time... which would mean I won't get out in time. However, the netweather storm risk charts are going with storms lasting well into the night in parts.

Can one of the experts shed some lights as to who is right?

[Andy Bown]

Looking for a positive amongst the lack of thundery activity here : we need the heavy rain :lol: !!

I think that as the front edges North the rain will turn heavier & some thundery activity will re-develop as it meets what will be warmer areas than those of us currently under the rain and stuck just above 15c. It may quite possibly link in with the cells over the Midlands.

[Tim B]

I wasn't expecting to say this quite so early (in to this event, given where I am) but I would not be surprised to see some thundery activity in my area today as there is already a dark area to my southwest / west where there appears to be a small area of convergence, no doubt things will likely change as the day wears on but right now I am just waiting for that distant boom.

[Herefordweather]

I personally think people just have to be patient and wait. Yes some areas will miss out, however areas that get a thunderstorm today will certainly know about it you feel.

Its cloudy here, but its shifting.

[Dp1981]

Morning all :lol: Its gone very dark here looks like night again there is no rain or anything but my sky box is flickering as if its bad rain

Are us in Swindon looking to get something at last?

[Kookylou]

well all is quiet here! i was looking forward to waking up to some lovely thunder but is drizzling but still very muggy. the weather forecasts on the BBC keep contradicting each other also - the national one says no thunder, just heavy rain and the local one says thunderstorms!

[VillagePlank]

Morning all,

Incredibly, we start off with some CIN this morning, but this is all gone by lunchtime, where the London area will see reasonably large amounts of CAPE, but, curiously, LI's not really condusive to storm formation. The cynic in me, suggests, rather like snow forecasting, if one element is out of place, then it's not going to happen. Here's the forecast skew-t:

In English this is a moderately convective environment. Where storms break out they are likely to contain hail (no larger than, say, 1p) and frequent CG strikes; even if not electrified cells will be have high precipitation rates. There isn't really a reasonable chance of severe (life-threatening) storms but the risk, although small, is still there.

It gets better in the SE as we head into this evening ...

It's better and cloud bases have lowered from 900hPa to 950hPa so increased chance of tornadic development especially with the shear around 800hPa, and the environment becomes moderately to highly unstable (K=33). Thunderstorms are likely, but the chance of severe, like earlier, whilst there, is low. LI is now in the right around, I'd hazard a guess of -3 or lower for t/storm formation, and CAPE is high suggesting hail and frequent CG.

For the SE area if you want the best of the day, head for Hampshire, if you can't travel be patient - the best chances for SE (Kent, and Sussex), I reckon, is later in the afternoon, although any time between 12z and 19z is good, becoming excellent towards the end of the period. I note that estofex put our little corner under a level one, and I think that's because of shear and is listed rather because of very heavy precipitation rates as oppose to anything else.

Edited June 26, 2009 by VillagePlank

[Neilsouth]

VillagePlank , bbc forecasts saying that the band of rain/storms will be dieing away by late afternoon/evening.

[VillagePlank]

VillagePlank , bbc forecasts saying that the band of rain/storms will be dieing away by late afternoon/evening.

GFS says different :lol: but there should be no storms lurking around after dark.

Edited June 26, 2009 by VillagePlank

[*AL*]

Morning all :lol: Its gone very dark here looks like night again there is no rain or anything but my sky box is flickering as if its bad rain

Are us in Swindon looking to get something at last?

Yes i can confirm some very heavy rain now in Swindon but no electrical activity, nothing again for Swindon but fingers crossed for later.

[Herefordweather]

Things seem to be kicking off towards Swindon now with sharp echo's trailing all the way to the Reading/London area. The start of things to come?

[slinky1989]

It's VERY dark here and just started raining heavily. No thunder/lightning though, just very heavy rain. Looks as if it's late evening outside, it's so so dark :lol:

I'm up at the windmill hill business park atm and the rain is just getting heavier

Edited June 26, 2009 by slinky1989

[ThunderWoman]

Yes i can confirm some very heavy rain now in Swindon but no electrical activity, nothing again for Swindon but fingers crossed for later.

Good morning!

Yes, very heavy rain here atm (just got in from the school run) hopefully we'll get some thunder too.

[Paul Sherman]

Looking good for later this afternoon for the London area, Currently have a Temp of 22c and dewpoint of 16c here in Leigh On Sea and good breaks appearing for Solar input.

So if we are are 72/61 already then if we can get to 81/66 then a potential Loaded Gun scenario not out of the question, going to be good to see those echoes moving North Westwards towards the South East later this afternoon.

Cape around 1,000jkg (The year of the Cape) but if temps and dews exceed what Models are showing we could once again like the 15th June see More Cape realised and possibly around the 1,200 - 1,400jkg area.

Paul S

[VillagePlank]

Looking good for later this afternoon for the London area, Currently have a Temp of 22c and dewpoint of 16c here in Leigh On Sea and good breaks appearing for Solar input.

So if we are are 72/61 already then if we can get to 81/66 then a potential Loaded Gun scenario not out of the question, going to be good to see those echoes moving North Westwards towards the South East later this afternoon.

Cape around 1,000jkg (The year of the Cape) but if temps and dews exceed what Models are showing we could once again like the 15th June see More Cape realised and possibly around the 1,200 - 1,400jkg area.

Yeah, I looked for that, particularly because of the lapse rates really high up, but, alas, no CIN Agree with 'best' risk for later in the afternoon, though GFS forecast CAPE >2,000 for London at 18z, too.

Edited June 26, 2009 by VillagePlank

[Paul Sherman]

Classic Loaded Gun Ascent VP!

Significant Hail Parameter as well (2cm)

Cape Values this year have been Insane!

[VillagePlank]

>2,000?, Where?

Yup - sorry, meant >1,200; bit of a hangover situation going on this morning.

Classic Loaded Gun Ascent VP!

Significant Hail Parameter as well (2cm)

Cape Values this year have been Insane!

Yup - missed that as well time to go back to bed ....

[A.J]

If I get a storm today I will count myself very lucky. All I expect today is for dull cloud to persist in the sky for much of the day.

pretty much as I posted first thing this morning......a bit of a let down I'm afraid, after the lovely warmth yesterday, today in the west midlands, it'll cool, overcast with occasional light drizzle, maybe a heavier burst later on, oh well, winter returns for a day...lol.....I shall be welcoming back the sun and warmth with open arms tomorrow!

[BrickFielder]

It is interesting to note that ESTOFEX have highlighted a potential problem with GFS and since it diverges somewhat with met office output, you have to look at more than one model for a clearer picture. For instance it seems unlikely that dewpoints will get above 16 degrees as GFS is suggesting.

It has also come to my attention that NMM seems better than the other models at forecasting low level winds and I think this will play a part today.

Forecast SkewT's are slightly off from the larkhill 6am sounding which suggests perhaps we need some breaks in the cloud to raise temperatures. Notice the relatively low cloud bases and very high cloud tops, but also that 850-500hPa lapse rates are not that impressive.

Another concern is that storms are firing over France in relative sunshine are leaving a messing trail of cloud over the UK which could dampen convection. This would suggest things may fire later over the UK rather than earlier.

Key area for me today from the models would be somewhere around cheltenham late afternoon with low level vorticity and low cloud bases suggesting weak convergence type funnels may develop. Wind Shear is pretty poor so tornados are unlikely.

It should be noted though that GFS suggests another area of convergence more towards the south east

Main risk would appear to be from slow moving bands of heavy rain. The good lapse rate through the zero degree istherm suggest we may get some hail and high cloud tops suggest some lightning. No real evidence of dry air aloft except perhaps the south west so things could be rather messy rather than discreet cells developing.

[Paul Sherman]

Err

Brick think you might need to check the obs for RAF Manston - Currently has a dewpoint of 18c - Maybe wrong data but quite a few areas in the South East recording close to 17c dewpoints now

Paul S

[Dp1981]

Whoooooo!!! first thunder of the year here in swindon rain so heavy the road like a river im so excited yeppyy!!!

[VillagePlank]

Brick think you might need to check the obs for RAF Manston - Currently has a dewpoint of 18c - Maybe wrong data but quite a few areas in the South East recording close to 17c dewpoints now

XCWeather has 18C Td's too at Headcorn.