Storm & Convective Discussion - 16/07/15 onwards

[Dami]

 Don't know how many times I have said on this forum to ignore the Iphone apps, BBC and met office symbols, a computer does this and 99% of the time it is wrong.. A meer guide! 

 

Stick the the words in the forecast and the brilliant minds on here 

You forget a lot of us older peeps didn't have the luxury of computers in our young day and relied on the BBC weather forecasts and 'the symbols'  to give us an idea of what the weather was going to do. I'm sure this still applies today,  although after having no storms and countless thunder symbols you learn to take this with a pitch of salt, but even the written word, no matter how well written can't be 100% true either. Forecasts are always a guide as you have stated. 

 

As for the weather, I would say I'm hoping for rain for my garden but as far as thunder if i get any i'll be lucky, and will be in NSC. 

 

But at least I can moan in there.

[Daniel*]

Cautiously intrigued by tonight E4 persists in showing something quite nasty/robust over C/S England, this is a forecasters nightmare largest concern will be problematic rainfall not T&L /hail side.

[kaz]

That's just typical! At least I have a risk!

Yup I'm in the isolated part to. I cant believe how much chopping and changing the weather services have been doing. I think in the end they were just waving their arms around the whole UK saying "possible storms" but that is what makes are weather so interesting.. Still hoping to see a little lightning.. crossing fingers and I will be sitting glued to NW radar and all my other weather gadgets

[Spikecollie]

Certainly warming and destabilising nicely over here in Limousin if you're going to share the same airmass in the UK. We've had ACAS on and off since early morning and it's currently 31c and incredibly humid feeling. LIG METAR says t-storms from 0200 well into tomorrow. Will keep you posted, and I look forward to reports of what the UK has to offer...

Edited August 12, 2015 by Spikecollie

[East_England_Stormchaser91]

Let's hope this time most of the clicks are over my area, not everywhere else that's been pummelled this year!

Will, Devon will be lucky to receive the best storm of the bunch if it does. It isn't an area that usually benefits well from a storm setup due to it's proximity to cooler surrounding waters. Somewhere like Cambridge or Lincolnshire would be an ideal place to move if you love storms.

1) they are in a favourable position regarding the land fetch and time for storms to mature and become severe

2) they mostly see the highest amounts of instability and highest temperatures to fuel the storms.

The same effect but of a much bigger scale and a lot more potent happens regarding the monsters that Belgium, NE France and Germany see.

I'm not trying to rain on your parade or anything! Just adding a bit of food for thought to perhaps stop frustration if you see very little in the way of storms, I.e not wanting to sue the met office/BBC!!

I wish you all the best!

[William Grimsley]

Will, Devon will be lucky to receive the best storm of the bunch if it does. It isn't an area that usually benefits well from a storm setup due to it's proximity to cooler surrounding waters. Somewhere like Cambridge or Lincolnshire would be an ideal place to move if you love storms.

1) they are in a favourable position regarding the land fetch and time for storms to mature and become severe

2) they mostly see the highest amounts of instability and highest temperatures to fuel the storms.

The same effect but of a much bigger scale and a lot more potent happens regarding the monsters that Belgium, NE France and Germany see.

I'm not trying to rain on your parade or anything! Just adding a bit of food for thought to perhaps stop frustration if you see very little in the way of storms, I.e not wanting to sue the met office/BBC!!

I wish you all the best!

You are correct, but last year Devon had some of the best thunderstorms, especially in September so it's not strictly true what you have said especially for night time set ups like tonight, most thunderstorms actually hug the coasts at night not inland.

Yup I'm in the isolated part to. I cant believe how much chopping and changing the weather services have been doing. I think in the end they were just waving their arms around the whole UK saying "possible storms" but that is what makes are weather so interesting.. Still hoping to see a little lightning.. crossing fingers and I will be sitting glued to NW radar and all my other weather gadgets

We should hopefully see something, even if it's pretty weak. Fingers crossed!

[Chris K]

Will, Devon will be lucky to receive the best storm of the bunch if it does. It isn't an area that usually benefits well from a storm setup due to it's proximity to cooler surrounding waters. Somewhere like Cambridge or Lincolnshire would be an ideal place to move if you love storms.

1) they are in a favourable position regarding the land fetch and time for storms to mature and become severe

2) they mostly see the highest amounts of instability and highest temperatures to fuel the storms.

The same effect but of a much bigger scale and a lot more potent happens regarding the monsters that Belgium, NE France and Germany see.

I'm not trying to rain on your parade or anything! Just adding a bit of food for thought to perhaps stop frustration if you see very little in the way of storms, I.e not wanting to sue the met office/BBC!!

I wish you all the best!

 

That may be true for more severe surface based storms and convection, but in this setup, Surface CAPE doesn't look particularly inspiring anywhere for long. It is the various factors that support elevated storms which still seem reasonable across much of S England.

 

However the same was said countless times before and we still ended up with zilch.

Edited August 12, 2015 by Chris K

[tomp456]

map.png

 

Another view on tonight tomorrow

 

This from Met Monkey

A beautiful map, just hope it verifies, and Mother Nature/the computers are not trolling again !

[Harry]

SBCAPE and MUCAPE looks pretty dismal on both GFS and NMM. 

 

On this basis I am not going to be getting too excited about this 'event'. 

 

The only notable MUCAPE slithers into the far SE during late Friday and early hours of Saturday, but that is only one NMM model and even then MUCAPE is pretty meagre.

 

To my eyes, it looks more of a heavy rain event than a thunder event, but happy to be wrong about that

[Nick L]

SBCAPE and MUCAPE looks pretty dismal on both GFS and NMM. 

 

On this basis I am not going to be getting too excited about this 'event'. 

 

The only notable MUCAPE slithers into the far SE during late Friday and early hours of Saturday, but that is only one NMM model and even then MUCAPE is pretty meagre.

 

To my eyes, it looks more of a heavy rain event than a thunder event, but happy to be wrong about that

 

To be honest, I don't think that's ever not been the case. This was never really looking like a big fireworks display. There will certainly be embedded flashes and bangs but nothing to write home about. As you say, the rain is what is concerning about this event.

[Harry]

To be honest, I don't think that's ever not been the case. This was never really looking like a big fireworks display. There will certainly be embedded flashes and bangs but nothing to write home about. As you say, the rain is what is concerning about this event.

 

To be honest, I haven't really been following the next few days with close interest apart from watching BBC forecasts...on the basis of the Beeb forecasts over the past couple of days you'd be thinking we were in for a light-fest!!

[East_England_Stormchaser91]

Biggest chance of something notable to my eye is what possibly comes in from Benelux/NE France tomorrow evening and night.

[Vorticity0123]

For the ones interested I have made a post in the Model output discussion thread, about the dynamics of tomorrow's low pressure area, along with a small peek into the chances of thunderstorms associated with this system. It can be found here: https://forum.netweather.tv/topic/83676-model-output-discussion-1st-august-00z/page-17#entry3245022.

[Chris K]

To be honest, I haven't really been following the next few days with close interest apart from watching BBC forecasts...on the basis of the Beeb forecasts over the past couple of days you'd be thinking we were in for a light-fest!!

 

Indeed...which is what initially got me excited (silly me!). Looks too much like bog standard 'thundery' rain to me with a few flashes for the lucky ones. Some bothersome rainfall accumulations for some parts still likely...

Edited August 12, 2015 by Chris K

[cotswoldsnow]

we need as much rain as possible here, so bring it on tonight/tomorrow

[East_England_Stormchaser91]

Couple of sferics between Rennes and Nantes. It's a start!

[Supacell]

There seems to still be a great deal of uncertainty with regards to where the heaviest rain will be and where the best of any thunderstorms will be over the next couple of days. I think it would be fair to say that the south coast and just inland from there to the M4 looks best overnight tonight but where the storms actually are is anyone's guess. It is normal in these scenarios though. It really will be a case of radar watching and then tracking storms as they come into the south coast.

 

The first batch of storms should then push north into the Midlands but at this point I have seen everything from them tracking NW to affect only the SW Midlands and Wales to NNW and affecting all of the Midlands and up into N England. On tracking north then I expect thunderstorms will tend to lose there intensity tomorrow. If we can get any sunshine breaking through behind this band then it will allow temperatures to shoot up as the air following this warm front is very warm and humid air. If the sunshine breaks through then I can see potentially some big storms breaking out and pushing NW. 

 

The next interest comes from the possibility of more storms coming out of France and Benelux towards the SE late tomorrow - and this is the area that interests me most from an IMBY point of view. Unfortunately this is 24 hours away or more and so the uncertainty here is quite high.

[Nights King]

To be honest, I don't think that's ever not been the case. This was never really looking like a big fireworks display. There will certainly be embedded flashes and bangs but nothing to write home about. As you say, the rain is what is concerning about this ev

 

 

That isn't the impression that many people viewing the Netweather front page headline "calm before the storms" will get? 

 

I do agree though that this will be mainly a rain event and some may not even get much of that.

[BrickFielder]

Some initial thoughts on tomorrow.

 

Pretty tricky to pin point tomorrow down as the models are still not in alignment, but I think we can talk about a few things the models are showing up.

 The first thing I noticed was that instability in the form of mixed layer cape and mid level lapse rates are not really that special on first look.

That might be a little misleading though since the initial storms coming in from the south are likely to be elevated.

 I think these storms form as a result of trough development behind the warm front with a strong possibility of elevated storms developing to the south of the UK and then reaching the south coast in the early hours. As those storms move inland then I think there is a chance that they will weaken as they move north. 700hpa vertical velocities seem to drop off as the storm move north.

Interestingly NMM suggests a bent trough with some interesting attributes to the bend down across the London area around mid day.

GFS via lightning wizard also picks up on the possibility of an over shooting top and a storm with its own dynamics.

 ( Link  http://www.lightningwizard.com/)

 

Later on across the south and perhaps into the midlands we might get some surface based storms, if the cloud clears a little. Since the air profile looks fairly moist all the way up apart from some areas towards West Wales this might be messy convection.

 

Still there is some surface based instability and low level wind convergence.

 

Since there is very little strength to the winds at 500 hpa (mid level) I dont see this really being utilised.

 

In summary its confusing picture which is not nailed down by the models yet and could still amount to no storms. Suggestions are at the moment that there will be some overnight elevated storms which will tend to become outflow dominate (heavy rain rather than stormy) as they move north and less electrical. Just a chance of a more intense storm mid day to early afternoon south eastern counties with a chance of some surface based storms late afternoon across the south coast moving northwards. Key areas are Brighton to Exeter overnight, perhaps Kent and London area mid day and south west stretching up into Wales late afternoon (perhaps getting as far north as the midlands).  Tomorrows models may off course move everything northwards into the north of the UK, with neither todays or tomorrows early models being correct, as plumes are notoriously hard for models to get right.

 

 

[William Grimsley]

The theta e has arrived here. Currently 22.6°C here with a dew point of 17.3°C so feeling muggy out of the very light wind. To me, I'm a little confused with recent posts but it now looks like central southern areas of England are more likely to bare the brunt of these thunderstorms even though many charts agree that there is still a good chance down here in the south west. We shall have to wait and see in a few hours!

 

Instability is also showing it's hand here with widespread Ac but no Ac Cas yet, I think that will become present after this very weak disturbance moves north.

Edited August 12, 2015 by William Grimsley

[Methuselah]

The theta e has arrived here. Currently 22.6°C here with a dew point of 17.3°C so feeling muggy out of the very light wind. To me, I'm a little confused with recent posts but it now looks like central southern areas of England are more likely to bare the brunt of these thunderstorms even though many charts agree that there is still a good chance down here in the south west. We shall have to wait and see in a few hours!

 

Instability is also showing it's hand here with widespread Ac but no Ac Cas yet, I think that will become present after this very weak disturbance moves north.

Does that mean I can't say, 'tis a wee bit black, over at Will's', then?

[William Grimsley]

Does that mean I can't say, 'tis a wee bit black, over at Will's', then?

It was pretty dark earlier, even some rain at Exeter Airport if very light so something is happening.

[Methuselah]

It was pretty dark earlier, even some rain at Exeter Airport if very light so something is happening.

Do you not have that old saying, in your part of the world, William? The first few times I heard it, I was right confused; the 'blackness' was in a different direction each time.

 

Anywho, good luck with the thundery stuff!  

[MP-R]

The theta e has arrived here. Currently 22.6°C here with a dew point of 17.3°C so feeling muggy out of the very light wind. To me, I'm a little confused with recent posts but it now looks like central southern areas of England are more likely to bare the brunt of these thunderstorms even though many charts agree that there is still a good chance down here in the south west. We shall have to wait and see in a few hours!

 

Instability is also showing it's hand here with widespread Ac but no Ac Cas yet, I think that will become present after this very weak disturbance moves north.

 

Humidity still at 48% here with just standard fair weather clouds - looking forward to the more thundery looking sky. Had it briefly here on Monday. We could indeed be entering the most interesting period convectively of the summer so far!

[William Grimsley]

Do you not have that old saying, in your part of the world, William? The first few times I heard it, I was right confused; the 'blackness' was in a different direction each time.

 

Anywho, good luck with the thundery stuff!  

Oh dear, I never knew it was a saying! :oops:Anyway, thanks and good luck to you, too!

Humidity still at 48% here with just standard fair weather clouds - looking forward to the more thundery looking sky. Had it briefly here on Monday. We could indeed be entering the most interesting period convectively of the summer so far!

Interesting! 71% here! Yeah, a thundery sky nearly makes my day, a rumble of thunder as well? That's enough to make me happy! Good luck!

Edited August 12, 2015 by William Grimsley