Convective / Storm Discussion Thread - 31st May 2017 onwards

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Thu 15 Jun 2017 - 05:59 UTC Fri 16 Jun 2017

ISSUED 19:54 UTC Wed 14 Jun 2017

ISSUED BY: Dan

... E ANGLIA / SE ENGLAND ...

Narrow plume of high WBPT and reasonable MLCAPE will be present across E Anglia and SE England first thing on Thursday morning - however, with no real upper forcing to destabilise (due to upper ridging) it is very unlikely any noteworthy deep convection will occur, before the plume moves offshore across the North Sea. That said, some AcCas with perhaps virga will be possible, with better chances of some destabilisation occurring as this plume drifts across the North Sea as heights begin to fall aloft.

The approaching cold front during the afternoon hours may provide the focus for a few scattered showers, but limited in depth due to very dry air overrunning aloft. Therefore, no threat levels have been issued for now.

... SCOTLAND / NORTHERN IRELAND ...

Behind the cold front, upper trough migrating eastwards will steepen mid-level lapse rates slightly with cool air aloft providing sufficient instability for numerous showers to form, some weakly-electrified. 

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-15

[White Clouds]

Hi guys new to the forum! Want to see a good thunder spell some time soon. Been a long time since I've seen a good humdinger!

[Vestan]

Talk of a 'thundery breakdown' on the BBC forecast tonight around the middle of next week, but uncertainties around whether it would be due to air coming up from the South or in from the West 

[TJS1998Tom]

17 minutes ago, Vestan said:

Talk of a 'thundery breakdown' on the BBC forecast tonight around the middle of next week, but uncertainties around whether it would be due to air coming up from the South or in from the West 

I just hope Lincolnshire will get something : P

Edited June 14, 2017 by TJS1998Tom

[Ben Sainsbury]

Again for Southern areas, it's looking very promising again! Especially for home grown surface based storms. Some impressive cape values too at this range but obviously taken with a pinch of salt.

ATM: Sunday - Eastern Areas

Monday - CS England

Tuesday - SW England + S Wales

though likely to change! 

Edited June 15, 2017 by Ben Sainsbury

[Chris.R]

8 hours ago, Vestan said:

Talk of a 'thundery breakdown' on the BBC forecast tonight around the middle of next week, but uncertainties around whether it would be due to air coming up from the South or in from the West 

 You have to have both for a breakdown otherwise what are you breaking down? lol bbc

[Allseasons-Si]

Didn't know where to post this but it is cool

 

[Flash bang flash bang etc]

I'm enjoying the sunshine but feel like it's gonna be an age before we see any good potential in these parts.

So disappointing when you think this is now supposed to be prime season and we've got such a hot spell coming up. Hate the way we generally lose about 3 weeks of UK summer potential for every small plume opportunity that comes along.

And yet just take a look a couple of hundred miles to the south and east - lightning up like a (summer) Christmas tree almost once a week!

Gah! 

[TJS1998Tom]

06Z shows quite a bit of Cape for Monday evening, it's increased once again compared to previous updates

[Flash bang flash bang etc]

23 minutes ago, TJS1998Tom said:

06Z shows quite a bit of Cape for Monday evening, it's increased once again compared to previous updates

Looking great so far - and plenty of time for things to improve even further :thumbs:

Keeping Monday late afternoon and overnight free for chasing as this could finally be our moment...

[TJS1998Tom]

1 hour ago, Flash bang flash bang etc said:

Looking great so far - and plenty of time for things to improve even further :thumbs:

Keeping Monday late afternoon and overnight free for chasing as this could finally be our moment...

Thankfully I'm off Monday afternoon so hopefully Lincoln will get something seeing as atm we're on the edges of the red area

[Summer Sun]

Day 3 Convective Outlook

VALID 06:00 UTC Sun 18 Jun 2017 - 05:59 UTC Mon 19 Jun 2017

ISSUED 20:18 UTC Fri 16 Jun 2017

ISSUED BY: Dan

Under broad upper ridging on Sunday, strong surface heating will yield SBCAPE values of up to 1,000 Jkg-1 with dewpoints typically in the high teens Celsius. Forecast profiles are very dry, but given some sea breeze convergence one or two isolated heavy showers / thunderstorms may develop in the very late afternoon into evening hours. Main risk will be local flash flooding given slow storm motion and PWAT of 30-35mm, suggesting 30-40mm may fall in a short space of time.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-18

[Flash bang flash bang etc]

27 minutes ago, Summer Sun said:

Day 3 Convective Outlook

VALID 06:00 UTC Sun 18 Jun 2017 - 05:59 UTC Mon 19 Jun 2017

ISSUED 20:18 UTC Fri 16 Jun 2017

ISSUED BY: Dan

Under broad upper ridging on Sunday, strong surface heating will yield SBCAPE values of up to 1,000 Jkg-1 with dewpoints typically in the high teens Celsius. Forecast profiles are very dry, but given some sea breeze convergence one or two isolated heavy showers / thunderstorms may develop in the very late afternoon into evening hours. Main risk will be local flash flooding given slow storm motion and PWAT of 30-35mm, suggesting 30-40mm may fall in a short space of time.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-18

Wish there was more detail... is this a capping situation?

[East_England_Stormchaser91]

10 minutes ago, Flash bang flash bang etc said:

Wish there was more detail... is this a capping situation?

Yeah I'd say so. But a triggering mechanism such as local convergence/sea breeze convergence may break the capping. Monday as it stands looks a more favourable day given slightly lower pressure and stronger CAPE. Any storms will have some decent structure exposed due to very clear conditions I would say, would make for great viewing, unlike the mid level claggy mess we normally get. 

[wimblettben]

48 minutes ago, East_England_Stormchaser91 said:

Yeah I'd say so. But a triggering mechanism such as local convergence/sea breeze convergence may break the capping. Monday as it stands looks a more favourable day given slightly lower pressure and stronger CAPE. Any storms will have some decent structure exposed due to very clear conditions I would say, would make for great viewing, unlike the mid level claggy mess we normally get. 

I tend to find that mid level storms produce more widespread storm coverage for everyone though.

[TJS1998Tom]

18z shows some nice amounts of Cape for Monday and especially Friday  (fingers crossed)

[TJS1998Tom]

Now this is one hell of a chart! Very interesting for next Friday, fingers crossed we keep this up throughout the week

[Summer Sun]

Day 3 Convective Outlook

VALID 06:00 UTC Mon 19 Jun 2017 - 05:59 UTC Tue 20 Jun 2017

ISSUED 07:51 UTC Sat 17 Jun 2017

ISSUED BY: Dan

Under broad upper ridging on Monday, strong surface heating will yield CAPE values of 1,000-1,500 Jkg-1 with dewpoints typically in the high teens Celsius. Forecast profiles are very dry, but given some low-level wind convergence a few isolated heavy showers / thunderstorms may develop in the late afternoon and early evening hours. Any storms that do manage to form (which remains uncertain) would be a capable of producing frequent lightning - but the main risk being local flash flooding given slow storm motion and PWAT of 30-35mm, suggesting 30-40mm may fall in a short space of time.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-19

___________________________________________________________________________________________________________________________________________________________________________________________

Day 4 Convective Outlook

VALID 06:00 UTC Tue 20 Jun 2017 - 05:59 UTC Wed 21 Jun 2017

ISSUED 08:01 UTC Sat 17 Jun 2017

ISSUED BY: Dan

Under broad upper ridging on Tuesday, strong surface heating will yield CAPE values of 1,000-1,500 Jkg-1 with dewpoints typically in the high teens Celsius. With a pronounced build of surface ridging north a cold front, this front will be forced southwards such that the area of convective interest will shrink southwards compared with previous couple of days. Once again, forecast profiles are very dry, but given some low-level wind convergence one or two isolated heavy showers / thunderstorms may develop in the late afternoon and early evening hours. Any storms that do manage to form (which remains uncertain) would be a capable of producing frequent lightning - but the main risk being local flash flooding given slow storm motion and PWAT of 30-35mm, suggesting 30-40mm may fall in a short space of time.

http://www.convectiveweather.co.uk/forecast.php?date=2017-06-20

Edited June 17, 2017 by Summer Sun

[Dangerous55019]

21 minutes ago, TJS1998Tom said:

Now this is one hell of a chart! Very interesting for next Friday, fingers crossed we keep this up throughout the week

Cheers for posting this @TJS1998Tom, and my thoughts exactly 

Almost a week ago I posted up some very juicy looking charts that I cherry picked. Ever since then I've been watching these charts wax and waning, but the one thing that struck me was how consistent they were in going for a time round about that date... Give or take a day or so either way.
I also said 'that at two weeks away, what could possibly go wrong?'... Well here we are one week on and the charts seem to be getting even more juicy. 
Still an awful lot of water to go under the bridge as they say, but dare I say that we could be on the cusp of quite a memorable week for a lot of people? 
Finger crossed for everyone who wants some storm action this coming week 



*Memo to Self: Mustn't get too carried away, as I'm still receiving counselling for the last bout of heat when all we had was one poxy clap of thunder.* 

[Flash bang flash bang etc]

25 minutes ago, Dangerous55019 said:

Cheers for posting this @TJS1998Tom, and my thoughts exactly 

Almost a week ago I posted up some very juicy looking charts that I cherry picked. Ever since then I've been watching these charts wax and waning, but the one thing that struck me was how consistent they were in going for a time round about that date... Give or take a day or so either way.
I also said 'that at two weeks away, what could possibly go wrong?'... Well here we are one week on and the charts seem to be getting even more juicy. 
Still an awful lot of water to go under the bridge as they say, but dare I say that we could be on the cusp of quite a memorable week for a lot of people? 
Finger crossed for everyone who wants some storm action this coming week 



*Memo to Self: Mustn't get too carried away, as I'm still receiving counselling for the last bout of heat when all we had was one poxy clap of thunder.* 

A clap of thunder??? Where?!

[Dangerous55019]

23 minutes ago, Flash bang flash bang etc said:

A clap of thunder??? Where?!

It was just before 06.00 on that Saturday at the end of May @Flash bang flash bang etc 
It was here in North east Wales. 

Edited June 17, 2017 by Dangerous55019
Forgot to say where it happened.

[A.J]

some ways out but looking at the NMM windflow charts, areas of interest for me on Monday would be West Midlands south westwards into South Wales given progged surface convergence, and on Tuesday south of the M4 across Salisbury Plain to the west country given sea-breeze convergence tied in with high Surface CAPE values and significant bouyancy with minimal capping......The airmass though is dry under high pressure so any storms that do develop would be well scattered IMO

[Mokidugway]

Normally would be excited about high cape values over the uk but with Glastonbury fast approaching I don't need a rerun of 2005 

   Was a bloody nightmare ,lol

Edited June 17, 2017 by Mokidugway

[Chris.R]

1 hour ago, Dangerous55019 said:

It was just before 06.00 on that Saturday at the end of May @Flash bang flash bang etc 
It was here in North east Wales. 

 You were very lucky, you got the very last sferic of the elevated MCS, it was just a few spots of rain by the time it reached me. As a rule   What ever you have, I usually get next. 

Edited June 17, 2017 by Chris.R

[TJS1998Tom]

06z Looking very impressive! Now with -9, suggests stronger storms than the 00z (still too early of course but one to look out for!)