Convective/Storm Discussion Thread 25/5/16 onwards

[Chris.R]

 A very warm night with a low of 16.5°C. Warming up nicely currently, 18.4°C. 

[Love Snow]

Fingers crossed today 

[Supacell]

Well we are off to a flying start this morning around here with crystal clear blue skies and it feels humid. It does look like numerous areas of thunderstorms should develop today with risk initially being near to high ground of N England, Scotland and Wales. The storms then appear to congregate along an eastwards moving trough this evening and overnight.

Most of the models break out storms over the Welsh Borders, N Pennines, Southern Uplands and generally across Scotland and N.I by early afternoon and transfer them eastwards. This evening the storms appear to congregate around the S and E Midlands and these last into the night time hours.

CAPE values are impressive today, well over 1000j/kg but there is very little wind shear once more. Triggering will once again be from convergence zones and orographic lifting which is why most storms will initially erupt over higher ground. Additionally a trough is moving eastwards across England. 

Although, like previous days, storms will struggle to organise they will still be intense when they do form. They could contain frequent lightning, hail up to 1.5cm in diameter and gusty winds. Perhaps more of a concern though is that with PWAT values over 30mm and slow storm motion there is the risk of localised flash flooding, I think this will be the talking point later.

I am at work until around 5:30pm but it is likely I will then be chasing around my local area should things pan out as planned

[Gordon Webb]

5 hours ago, CreweCold said:

Not looking good for Cheshire area tomorrow as wind convergence sets up further E with the focal point being central/east Midlands based on current hi res modelling. GFS wants a gentle NW'ly here by afternoon so we won't see anything from that direction. If I could pick a location for later on tomorrow afternoon it'd be Derby, down through Leicester, Coventry and perhaps as far S&E as Northampton.

well this has me worried , i know it's an exciting day for most of you but for me it's a day i could well do without lets just hope these potential showers / storms miss me or at least not hit me directly , just our of curiosity when is the most liely time for me in Bedworth is it late afternoon or ealier in the day NetWx-SR Model shows more at 3pm and 9pm with not much down the spine at 6pm  , I assume noone can say for certain if i will or won't see anything I'll just have to hope it misses me

[Gordon Webb]

14 minutes ago, Supacell said:

 

 

as they are transferring eastwards what do you think time is they'll be moving through me if i'm unlucky enough to see one (my perspective)

 

edit - bbc graphics show them moving eastwards between 5pm and 8pm reachng more eastern midland areas by 9pm

 

and carol k did point out that not everybody will see them lets hope that's me

Edited June 7, 2016 by Supacell
Removed quote to save space

[NO LONGER POSTING]

Personally for me today, the hot spot looks just north west of London (outside the m25) places around Milton Keynes again. Although I would also think perhaps around reading area too.

Convergence zone anybody?

 

NETWX

Euro4

NNM 

 

 

 

[Nick F]

Storm & Convective Forecast

Issued 2016-06-07 06:25:26

Valid: 07/06/2016 06z to 08/06/2016 06z

DAY 1 CONVECTIVE FORECAST - TUES 7TH-JUNE-2016

Synopsis

Upper ridge that has dominated aloft across the UK these past few days will edge eastward and decline on Tuesday, allowing a shortwave upper trough to move NE from the base of large-scale trough over the Atlantic to the west. This trough, combined with surface convergence  within slack surface pressure pattern will trigger a more widespread risk of thunderstorms on Tuesday compared to recent days.

... MUCH OF THE UK & IRELAND ...

A few showers and thunderstorms maybe ongoing first thing Tuesday morning across the Irish Sea, N Wales, N. Ireland and outer islands of western Scotland. Otherwise, clear skies across much of the UK will allow strong surface heating of a moist airmass characterised by PWAT (Precipitable Water) values of 1.2 / to 1.6 inches - which combined with modestly steep lapse rates aloft will generate quite large CAPE values (for the UK) ... ECMWF indicates 800-1500 j/kg CAPE inland across the UK this afternoon. This convective energy will likely be released as a shortwave trough in the mid-upper flow advances NEward across the UK today combining with surface breeze convergence to erode the cap and build storm clouds. Despite very weak vertical shear, large CAPE values will sustain ... for short periods ... locally strong to marginally severe storms, capable of producing isolated large hail (1-2cm diameter), locally strong wind gusts, frequent cloud-to-ground lightning and torrential rain leading to flash-flooding. Therefore have issued a MARGINAL risk for severe weather. Surface convergence may allow funnels or even a brief / weak tornado to develop with stronger updrafts into storms. Thunderstorms may continue overnight in some places, though severe risk will lessen.

Issued by Nick Finnis

[Supacell]

10 minutes ago, Gordon Webb said:

 

as they are transferring eastwards what do you think time is they'll be moving through me if i'm unlucky enough to see one (my perspective)

 

edit - bbc graphics show them moving eastwards between 5pm and 8pm reachng more eastern midland areas by 9pm

 

and carol k did point out that not everybody will see them lets hope that's me

It is too hard to pick a definite time but 8-9pm would be a good guess. If you are on this forum you will know if there are storms around as I am sure people will be reporting on it. You can also use one of the Netweather lightning detectors. As has been said any storms will be isolated. Let's hope they leave you alone but move over my house (or my car) instead

[Weather-history]

30 minutes ago, Gordon Webb said:

well this has me worried , i know it's an exciting day for most of you but for me it's a day i could well do without lets just hope these potential showers / storms miss me or at least not hit me directly , just our of curiosity when is the most liely time for me in Bedworth is it late afternoon or ealier in the day NetWx-SR Model shows more at 3pm and 9pm with not much down the spine at 6pm  , I assume noone can say for certain if i will or won't see anything I'll just have to hope it misses me

I still don't get why you hang around these threads, Gordon. Surely reading the posts on here is only going to exacerbate your fears? Isn't the best policy for you is to carry on as normal rather than hanging on to this thread, feeding your fear with what "ifs"? 

[Gordon Webb]

31 minutes ago, Weather-history said:

I still don't get why you hang around these threads, Gordon. Surely reading the posts on here is only going to exacerbate your fears? Isn't the best policy for you is to carry on as normal rather than hanging on to this thread, feeding your fear with what "ifs"? 

Yep probably hanging around here reading forecasts potential and reports isn't doing me any good but it's a habit i seemed to have developed perhaps i should try and stop

[Frosty hollows]

7 hours ago, Mapantz said:

Just a quick smattering of hi-res images before I head to Bedfordshire..

  

  

They're not to be taken literally, but the recent upgrade to the NetWx model has made them pretty good for mesoscale developments.

Think I'll take my raincoat to work then!

[Azazel]

2 minutes ago, Gordon Webb said:

Yep probably hanging around here reading forecasts potential and reports isn't doing me any good but it's a habit i seemed to have developed perhaps i should try and stop

come and live in Hampshire Gordon where you are guaranteed to literally never see a storm:)

[Frosty hollows]

57 minutes ago, Surrey said:

Personally for me today, the hot spot looks just north west of London (outside the m25) places around Milton Keynes again. Although I would also think perhaps around reading area too.

Convergence zone anybody?

 

NETWX

Euro4

NNM 

 

 

 

\i'm thinking north of the M4 corridor. Not being imby of course!!

[Chris K]

Hmm looks like I may be a bit too far SW away from the main chances of storms today. Perhaps I will head out later after work depending where they form.

[William Grimsley]

Looks like my risk is very low today then, we have some elevated drizzle if that counts? LOL.

I think my best bet today is along the south coast towards Dawlish, what are people's thoughts on that?

Edited June 7, 2016 by William Grimsley

[Frosty hollows]

17 minutes ago, Gordon Webb said:

Yep probably hanging around here reading forecasts potential and reports isn't doing me any good but it's a habit i seemed to have developed perhaps i should try and stop

I do feel for you as I know what it's like to be anxious about weather..mine is strong winds, and gathering as much information about upcoming weather events does help me,.However, just be cautious where you get your information from. This probably isn't the best forum for your nerves as we'll all ramp up an altocumulus into a full blown cell. Today is most likely going to be a warm sunny day with a marginal/slight risk of stomrs which most people will avoid. So try to enjoy the day for what it will be for most of us(and most likely you), a warm sunny early summer day 

[William Grimsley]

I agree with Frosty some what, but really I've found with my therapy with anxiety is you actually need to go and experience the anxiety as it's the only way you learn to cope with these challenges and then you see that they're actually not as bad as you think. For example, me driving all the way up to Somerset a few months ago would've been very tough but seen as I've now been driving for so long, it's made it easier for me to achieve. Something to think about anyway. Now, if I do drive down to Dawlish today, that gives me a little anxiety (new place etc.) but I know what to do in order to make it easier.

"You'll never know until you try."

Back on topic now.

Edited June 7, 2016 by William Grimsley

[ancientsolar]

Portsmouth-Brighton, may see something soon, storm heading NW,. not much on it, but a sferic has been seen pretty far North of the channel. 

[Lauren]

Hmm, any potential stormy action looks to happen whilst I'm in training after work. Boo!

[tomp456]

4 minutes ago, ancientsolar said:

Portsmouth-Brighton, may see something soon, storm heading NW,. not much on it, but a sferic has been seen pretty far North of the channel. 

Sky looks greyish to the south, not getting excited just yet. 

[Chris.R]

 22.0°C, sun coming out. Feeling incredibly oppressive. 

[Gordon Webb]

1 hour ago, Nick F said:

Storm & Convective Forecast

Issued 2016-06-07 06:25:26

Valid: 07/06/2016 06z to 08/06/2016 06z

DAY 1 CONVECTIVE FORECAST - TUES 7TH-JUNE-2016

Synopsis

Upper ridge that has dominated aloft across the UK these past few days will edge eastward and decline on Tuesday, allowing a shortwave upper trough to move NE from the base of large-scale trough over the Atlantic to the west. This trough, combined with surface convergence  within slack surface pressure pattern will trigger a more widespread risk of thunderstorms on Tuesday compared to recent days.

... MUCH OF THE UK & IRELAND ...

A few showers and thunderstorms maybe ongoing first thing Tuesday morning across the Irish Sea, N Wales, N. Ireland and outer islands of western Scotland. Otherwise, clear skies across much of the UK will allow strong surface heating of a moist airmass characterised by PWAT (Precipitable Water) values of 1.2 / to 1.6 inches - which combined with modestly steep lapse rates aloft will generate quite large CAPE values (for the UK) ... ECMWF indicates 800-1500 j/kg CAPE inland across the UK this afternoon. This convective energy will likely be released as a shortwave trough in the mid-upper flow advances NEward across the UK today combining with surface breeze convergence to erode the cap and build storm clouds. Despite very weak vertical shear, large CAPE values will sustain ... for short periods ... locally strong to marginally severe storms, capable of producing isolated large hail (1-2cm diameter), locally strong wind gusts, frequent cloud-to-ground lightning and torrential rain leading to flash-flooding. Therefore have issued a MARGINAL risk for severe weather. Surface convergence may allow funnels or even a brief / weak tornado to develop with stronger updrafts into storms. Thunderstorms may continue overnight in some places, though severe risk will lessen.

Issued by Nick Finnis

just wondering when you say cape will sustain only for short periods why what happens ?

[P-M]

Well here in Durham just to the east of the Pennines it's humid very warm and blue sky's apart from to my west where it looks a bit more milky.  Beautiful day either way here - bonus to get a storm but if not I am enjoying this taste of summer!

[alexisj9]

5 minutes ago, Gordon Webb said:

just wondering when you say cape will sustain only for short periods why what happens ?

Pulse storms that form and then dissipate Quickly.

[tomp456]

19.2C, feels like 22.7C with 80% humidity.