Storm/convective Discussion 26th June >>

[Costa Del Fal]

big down grade for WEDNESDAY...compared to earlier....hopefully an upgrade by next week.....

BBC..going anything north of M4 for today for some potent TS

as Nick also quoted

Not a surprise tbh! The Cape has been on a rollercoaster all week anyway so expect more upgrades and downgrades imo.

[johnholmes]

Be interesting to see where and when the sea breeze front develops inland from the south coast today across Sern England, as this area looks likely to be the focus of some quite potent storms later.

GFS indicates this CZ developing roughly along the M4 corridor by 15z, quite tempted to drive out towards Berks/Wilts/Oxon later if it looks like Cu will develop, though traffic will probably be a nightmare.

EDIT: looking at that Herstmonceux sounding John's posted - inland across the SE we are expecting temps of 27 or even 28C and dewp of high teens, so initition looks quite achievable from that ascent and cloud tops would reach 35,000ft. Would need to be away from coast though where slightly more stable conditions are likely. Best chance towards M4/Thames corridor.

as you suggest Nick, the sea breeze may well be a trigger in kick starting it in places in the SE. I'd be very surprised not to see a batch of storms in the areas that get sunshine into the mid afternoon, SE and other places so favoured.

another help will be as temps rise so a minor surface low is going to form around the London area, be it north W or S of the city itself. This in turn causes air to rise so helping initiate deep convection today.

Edited June 27, 2009 by johnholmes

[dogs32]

Not a surprise tbh! The Cape has been on a rollercoaster all week anyway so expect more upgrades and downgrades imo.

if only B)

back today...sunny here and getting fairly warm

.plzzzz

Edited June 27, 2009 by dogs32

[VillagePlank]

Best chance towards M4/Thames corridor.

Yup - non heat based initiation best place in said area ...

And, if you'll excuse a ramp, heading for the North Downs from the West, too B)

EDIT: Convergence zone tornadoes along M4, today?

Edited June 27, 2009 by VillagePlank

[Geordiesnow]

Looks like its going to turn much hotter next week but i'm surprised to see quite a bit of PPN predicted despite pressure being so high, i can only assume that the air will be unstable aswell as its being quite humid.

Not looking forward to those warm sticky nights.

[maidstone weather]

Yup - non heat based initiation best place in said area ...

And, if you'll excuse a ramp, heading for the North Downs from the West, too :o

EDIT: Convergence zone tornadoes along M4, today?

I'm in Sevenoaks this evening - maybe a nice treat? B)

[slinky1989]

Yup - non heat based initiation best place in said area ...

And, if you'll excuse a ramp, heading for the North Downs from the West, too

EDIT: Convergence zone tornadoes along M4, today?

Looking good for swindon then Although I fear we may be a little too far west to catch any decent storms today. Still, will be good for cloud watching

[VillagePlank]

I'm in Sevenoaks this evening - maybe a nice treat?

Mr Murray might be playing under the roof, later, perhaps; certainly a radar watching day; key areas, I think, are M4, Cambridgshire, and Cheshire. Hopefully the largely unstable atmosphere across the UK should mean that t/storms might travel and be self sustaining over large (ish) distances.

Edited June 27, 2009 by VillagePlank

[Nick F]

Yup - non heat based initiation best place in said area ...

And, if you'll excuse a ramp, heading for the North Downs from the West, too

EDIT: Convergence zone tornadoes along M4, today?

Have got robust looking towering cumulus developing in the blue skies here now in west Kent, so looking more likely we could have storms in the SE this afternoon. Still, may have to get mobile and head W and NW I think for best potential when the sea breeze front moves inland later. Think Bracknell would be my initial target and points west and NW from there.

And yes, weak CZ tornadoes aren't out the equation either, as mentioned in the N-W forecast.

[WindWatcher]

It looks like the thick cloud we are under at the moment in Southampton is from a convergence zone. If you look here http://www.sat24.com/gb you can see the winds converging and the cloud piling up.

[Kain]

Still quite hazey here from yesterday.

However can see some TCu's building very nicely through the haze.

Pretty horrid here too, its all muggy and sticky

[A.J]

still stuck under cloud cover here, however its now looking a lot clearer 20 or so miles to the south on the sat24 vis image....even so, still 20.6C and very humid & still....I think I'm in a very good area for this afternoon with the chances of storm firing to the NW of Birmingham looking at the forecasts

[VillagePlank]

London (and surrounding ares, skew-t) ... for 18z tonight ...

A small convective profile (K=24) but with some reasonable instability (LI=-4) Cloud bases have raised and their heights are, perhaps, a little less than forecast at 00z. CAPE agrees with LI, rather than K, so suggests that t/storms will form, and that those that do form will be of a standard British type, with a very outside chance (less than 5%) of a severe storm. They will be isolated.

In order to realise CAPE (and get this sounding) surface heating needs to be in excess of, say, 24C, and , I thnk, dewpoints will need to be reasonably high at >15C or other factors needs to come into play such as the CZ already discussed.

Here's looking for M4 imports

Edited June 27, 2009 by VillagePlank

[dogs32]

still stuck under cloud cover here, however its now looking a lot clearer 20 or so miles to the south on the sat24 vis image....even so, still 20.6C and very humid & still....I think I'm in a very good area for this afternoon with the chances of storm firing to the NW of Birmingham looking at the forecasts

getting fairly warm here AJ....very sunny so the sun is on its way AJ

[Kain]

Within the last 10 mins the sun has really start to burn off that haze/mist from yesterday.

Heres hoping that today is actually friday and we get what we ment to have had yesterday...TODAY!

(Try saying that when you have had one too meny)

[Phil UK]

Good morning all.

Solihull current conditions are broken cloud, sun not long popped out after all the mist and other general murk has cleared apart from the humidity and I can see convection kicking off already.

M4 eh? I think it will be a lot further north than that if I'm reading into this correctly.

Watch this space. Otherwise if anyone wants me, I'll be mostly in the 'No Storms Club' thread.

Phil.

[Jane Louise]

Within the last 10 mins the sun has really start to burn off that haze/mist from yesterday.

Heres hoping that today is actually friday and we get what we ment to have had yesterday...TODAY!

(Try saying that when you have had one too meny)

Lol

Anway, the sun is shining brightly here with blue skies all around. A good start for today

[Nick F]

Towards the end of next week/next weekend looks very interesting on 06z GFS and 00z ECM, with a proper Spanish Plume scenario developing with a long draw moist and unstable southerly along with strengthening upper winds as an upper trough edges in from the Atlantic - bringing the threat of severe weather. Shame its along way off.

[dogs32]

Towards the end of next week/next weekend looks very interesting on 06z GFS and 00z ECM, with a proper Spanish Plume scenario developing with a long draw moist and unstable southerly along with strenghtening upper winds as an upper trough edges in from the Atlantic - bringing the threat of severe wetaher. Shame its along way off.

YES..thats the one Im watching...If this can only hold together Nick we might get are old style storms

[Nick F]

Good morning all.

Solihull current conditions are broken cloud, sun not long popped out after all the mist and other general murk has cleared apart from the humidity and I can see convection kicking off already.

M4 eh? I think it will be a lot further north than that if I'm reading into this correctly.

Watch this space. Otherwise if anyone wants me, I'll be mostly in the 'No Storms Club' thread.

Phil.

It won't be just the M4 area, it's just where the sea breeze/convergence zone is likely to develop later, scattered t-storms are likely almost anywhere in England away from the NE. The CZ most likely to see t-storms organise though in what is a weakly sheared environment which leades to scattered and unorganised pulse storms normally.

Turkey-towers still going up here atm in lovely dark blue skies.

[LeeKay]

Wont be long AJ till you get the cloud break. It broke here around 5 mins ago and like Phil said can see the convection taking place now.

[A.J]

It won't be just the M4 area, it's just where the sea breeze/convergence zone is likely to develop later, scattered t-storms are likely almost anywhere in England away from the NE. The CZ most likely to see t-storms organise though in what is a weakly sheared environment which leades to scattered and unorganised pulse storms normally.

Turkey-towers still going up here atm in lovely dark blue skies.

quick question Nick re. convergence zone.....will these potential storms just drift along the convergence zone?...if not, what direction would you expect them to track?.....cheers

Wont be long AJ till you get the cloud break. It broke here around 5 mins ago and like Phil said can see the convection taking place now.

Thanks bud.....here's to a hot, sunny & later stormy afternoon!

[dogs32]

fairly large cumunimbus's to the W/NW of here...maybe 20 miles away heading North by the looks of it

[maidstone weather]

yeah some good convection here, specially to the northwest towards London (as always!)

[dallas]

can already see what looks like tower cloud bubbling up towards Essex much use of the Netweather radar for the bbq today