Storm & Convective Discussion - 01/09/14 onwards

[Gordon Webb]

This was probably one of the best supercells the Uk has seen. 28th june 2012, this is the storm which gave Leicestershire the baseball sized hail and one of the largest UK tornado's captured in Sleaford, Lincolnshire. 

 

 

 

I remember that day well was sitting in my bedroom praying like hell we wouldn't get it and I was lucky that day got very dark but didn't even rain just skirted to the north got a storm between 12pm and 1 pm but by 2pm blue skies and the wouldn't have known any different

[Paul Sherman]

July 19th This Year also had some amazing Parameters like 28th June 2012, with Temps around 82f and Dewpoints in the low 70's and with 40kts of Low Level Shear would probably have been a High End Slight in the States, this also produced a very nice Classic Supercell that tracked from Swindon to just South of Oxford, there was also a Supercell in Derbyshire earlier this year and if you go onto Ukww you can see the picture of this HP Supercell on the front page.

 

Some years we get nowt and some years we get a few, if the parameters are there then we can and WILL get Supercell Storms in the Uk!

[Gordon Webb]

July 19th This Year also had some amazing Parameters like 28th June 2012, with Temps around 82f and Dewpoints in the low 70's and with 40kts of Low Level Shear would probably have been a High End Slight in the States, this also produced a very nice Classic Supercell that tracked from Swindon to just South of Oxford, there was also a Supercell in Derbyshire earlier this year and if you go onto Ukww you can see the picture of this HP Supercell on the front page.

 

Some years we get nowt and some years we get a few, if the parameters are there then we can and WILL get Supercell Storms in the Uk!

 

Can't remember if that was the storm that I got about 4pm in Bedworth only lasted 30 mins but the garden was like a swamp afterwards

[Supacell]

The 28th June 2012 supercell was an awesome beast and I don't recall anything quite like that since I have been tracking storms. Unfortunately I didn't get to see any of the golf ball hail or tornadoes but I did chase it and it was still impressive to see.

 

Paul, the supercell in Derbyshire that you speak of occurred on 9th June. I chased this one all the way from Uttoxeter in Staffordshire, through Derbyshire, Nottinghamshire and then Lincolnshire.

 

Another big storm around this area was on July 19th. This is not the Swindon/Oxford supercell but occurred earlier in the afternoon, tracking through Warwickshire, Leicestershire, Derbyshire and then up the M1 into Yorkshire. I am not sure if this was a supercell but appeared to be from the ground. That one goes down as the storm of the year for me! I am pretty sure this is the storm you are talking about Gordon, it happened after a night time of lightning storms across the country that left residual cloud. I remember it taking about half hour for storms to erupt once the sun got through the clouds showing the level of instability was high. This was also the day that Estofex gave out a rare level 2 warning for the UK.

[A.J]

July 19th This Year also had some amazing Parameters like 28th June 2012, with Temps around 82f and Dewpoints in the low 70's and with 40kts of Low Level Shear would probably have been a High End Slight in the States, this also produced a very nice Classic Supercell that tracked from Swindon to just South of Oxford, there was also a Supercell in Derbyshire earlier this year and if you go onto Ukww you can see the picture of this HP Supercell on the front page.

 

Some years we get nowt and some years we get a few, if the parameters are there then we can and WILL get Supercell Storms in the Uk!

remember it well mate, chased that sucka across the Marlborough Downs into Oxfordshire, posted some pics of it in the convective thread of the day, got quite a nice wall cloud, the first genuine wall cloud I'd ever seen in the flesh in the UK

[Mapantz]

Something of interest showing up along southern counties on Thursday evening, perhaps thundery.

[East_England_Stormchaser91]

I remember that day well was sitting in my bedroom praying like hell we wouldn't get it and I was lucky that day got very dark but didn't even rain just skirted to the north got a storm between 12pm and 1 pm but by 2pm blue skies and the wouldn't have known any different

Blimey, that must've been a close shave! literally a few KM if that. I just remember seeing a wall of black all day to the NW, had I have had a car back then, I would've chased it all the way!

[A.J]

just been rooting through some of my footage from the Sept 18th storms....some decent lightning captures

 

 

 

 

[Nick F]

Risk of some heavy showers and thunderstorms arriving from the SW overnight across southern areas, as steep lapse rates and forcing form ascent from a shortwave trough follow the rain spreading northeast this afternoon:

 

Storm & Convective Forecast

 

 

Issued 2014-10-15 09:37:20

Valid: 15/10/2014 1200z to 16/10/2014 1200z

 

THERE IS A RISK OF THUNDERSTORMS FORECAST

 

Synopsis

Upper trough/low overspreads the North Atlantic atop of a deep depression west of Ireland, which will slowly fill in situ over the next few days. A strong Atlantic jet rounds the base of the upper trough, the left exit approaching English Channel/Nern France overnight.

 

... S ENGLAND & S WALES TONIGHT ...

 

Behind occluded front moving NE bringing stratiform cloud and rainfall this afternoon, airmass characterised by steep lapse rates will move in from the SW across southern Britain overnight. GFS indicates a few 100 j/kg MLCAPE spreading up from the SW in conjunction with these steeper lapse rates. Forcing for ascent will increase overnight too, as shortwave trough is expected to move in from the SW along with increased divergence aloft north of left exit region of strong jet over Nern France/Channel. An area of heavy showers and thunderstorms along/near this trough looks to spread NE across S England and perhaps S Wales. These storms will be mainly elevated in nature as they move onshore, with localised flooding from heavy rainfall, strong wind gusts and hail the main threats. Over sea/coastal areas, cloud bases maybe lower, so there is potential for an isolated tornado/waterspout with strong more buoyant updrafts over warm SSTs where winds back ahead of approaching trough

Edited October 15, 2014 by Nick F

[Supacell]

Some potential over the next few days possibly. I am looking at the GFS 06z take on Friday night into Saturday, looks like a combination of weak CAPE, plenty of shear, helicity all coming together to give some organised storm/tornado potential. The GFS 12z delays it and gives Ireland some good storm potential late Friday into Saturday. It's something to watch

[Mapantz]

Looking very lively down to the southwest. .

 

[William Grimsley]

Yeah, those thunderstorms in the SW are lovely. I hope they don't die which they probably will or turn S or N of me and intensify like normal.

[Mark Parsons]

Yeah, those thunderstorms in the SW are lovely. I hope they don't die which they probably will or turn S or N of me and intensify like normal.

That's  what usually happens!!!

[William Grimsley]

That's  what usually happens!!!

Yeah, it used to happen to me a lot though recently I've caught some horrendous thunderstorms!

Edited October 15, 2014 by William Grimsley

[ChezWeather]

July 19th This Year also had some amazing Parameters like 28th June 2012, with Temps around 82f and Dewpoints in the low 70's and with 40kts of Low Level Shear would probably have been a High End Slight in the States, this also produced a very nice Classic Supercell that tracked from Swindon to just South of Oxford, there was also a Supercell in Derbyshire earlier this year and if you go onto Ukww you can see the picture of this HP Supercell on the front page.

 

Some years we get nowt and some years we get a few, if the parameters are there then we can and WILL get Supercell Storms in the Uk!

 

June 9th and July 19th both potential supercells here 

[Costa Del Fal]

Kicking off nicely here now with some bright flashes of Lightning and long rumbles of thunder!

[Costa Del Fal]

Moved away now. Lightning detectors suggest the whole thundery element has died off for now. If so then we were very lucky. A very nice storm on the whole with torrential rain, close lightning and long, deep rumbles of thunder. Very respectable.

[Mapantz]

It looks very well organised now. I'll be happy with some torrential rain to honest, anything else is a bonus.

Edited October 15, 2014 by Mapantz

[William Grimsley]

It looks very well organised now. I'll be happy with some torrential rain to honest, anything else is a bonus.

I have to agree, some good heavy/torrential constant rain would be nice with the odd flash and rumble thrown in.

[Costa Del Fal]

So far the Met Office symbols were bang on the money tonight. They only ever showed thunder for us in West Cornwall and that remains true thus far. Will it be correct for more thunderstorms again tomorrow evening?

[Nick F]

Storm & Convective Forecast

 

Issued 2014-10-16 08:38:40

Valid: 16/10/2014 0600z to 17/10/2014 0600z

 

 

THERE IS A RISK OF THUNDERSTORMS FORECAST

 

Synopsis

Amplified upper level trough over the N Atlantic and slow-moving deep depression west of Ireland will continue to drive a increasingly warm SWly flow across western Europe, the flow unstable across Ireland, western UK and southern England.

 

... IRELAND, WERN BRITAIN and S ENGLAND ...

 

Increasingly moist air will advect NE at lower-levels today, generally lapse rates will be steepest across Ireland, the Irish/Celtic Seas and western coastal areas where mid-level temperatures will be coldest close to the upper trough to the west over the Atlantic.  So the greatest potential for thunderstorms today will be across Ireland, SW England, N & W Wales, IoM and coastal areas of NW England. Here, low-level shear may become sufficiently strong for a low risk of a tornado/waterspout - particularly near coastal areas with influence of seasonally warm SSTs.

 

Further east across S England, a more isolated risk of a few thunderstorms later, as a few shortwave troughs in the strong southwestelry flow aloft move through steepening lapse rates and creating forcing for ascent to bring enhanced areas of convection. Any storms here could organise, given strong flow aloft, though risk of severe weather looks too isolated to warrant a categorical risk.

 

Any storms will be capable of producing torrential rain leading to localised flooding, hail and strong gusty winds.

Edited October 16, 2014 by Nick F

[Chris.R]

Storm & Convective Forecast

 

Issued 2014-10-16 08:38:40

Valid: 16/10/2014 0600z to 17/10/2014 0600z

 

convmap_161014.png

 

THERE IS A RISK OF THUNDERSTORMS FORECAST

 

Synopsis

Amplified upper level trough over the N Atlantic and slow-moving deep depression west of Ireland will continue to drive a increasingly warm SWly flow across western Europe, the flow unstable across Ireland, western UK and southern England.

 

... IRELAND, WERN BRITAIN and S ENGLAND ...

 

Increasingly moist air will advect NE at lower-levels today, generally lapse rates will be steepest across Ireland, the Irish/Celtic Seas and western coastal areas where mid-level temperatures will be coldest close to the upper trough to the west over the Atlantic.  So the greatest potential for thunderstorms today will be across Ireland, SW England, N & W Wales, IoM and coastal areas of NW England. Here, low-level shear may become sufficiently strong for a low risk of a tornado/waterspout - particularly near coastal areas with influence of seasonally warm SSTs.

 

Further east across S England, a more isolated risk of a few thunderstorms later, as a few shortwave troughs in the strong southwestelry flow aloft move through steepening lapse rates and creating forcing for ascent to bring enhanced areas of convection. Any storms here could organise, given strong flow aloft, though risk of severe weather looks too isolated to warrant a categorical risk.

 

Any storms will be capable of producing torrential rain leading to localised flooding, hail and strong gusty winds.

I like it!

[TonyH]

Some very heavy showers across SW Wales but no sferics as yet, cant be far off though..

Edited October 16, 2014 by TonyH

[Mapantz]

Clouds shooting up all around me at the moment.

[TonyH]

Downpour here