Convective / Storm Discussion Thread - 31st May 2017 onwards

[Flash bang flash bang etc]

Shaping up!

[karyo]

The 6z gfs looks pretty good for north wales and nw england for much of the day tomorrow. It often overdoes precipitation so I will wait for the euro 4 to update later.

It looks like the showers/storms will be fast moving here which is not ideal as you don't get much of a chance to observe and enjoy the action but beggars can't be choosers.

[Windblade]

Yeah, looking good so far. 

[Flash bang flash bang etc]

I think the header pic at the top of this page is a good indication of what we can expect across the Home Counties 

[LightningLover]

Oh, I do love the anticipation on this forum. Its really uplifting, and it is getting my hopes up even further! Maybe this will be the event to break the 2016 curse? Lets See!  (I am also liking Nicks Forecast! has me in the highest warning zone for today and tomorrow! )

[NO LONGER POSTING]

Good luck all, started my new job today couldn't have picked a better week to start. 

 

Some of the charts coming out for tonight and tomorrow are astonishing 

[Derecho]

I am much more optimistic places will see some good storms tomorrow. Anyone who followed this thread during the last hot spell will have probably noticed that I wasn't convinced there would be a thundery breakdown. Unfortunately that turned out to be true but the met office forecast radar was never bullish.

This time however the forecast radar looks very promising indeed.

Here are my thoughts on how the day will go:

- Storms will begin crossing the channel very early in the morning and hit the South coast around 7ish. These will then intensify and become more organised through the morning esecially as they pass through more inland areas. They will eventually move up to the wash and clear the North Sea.

- I then espect some good storms to form over Wales during midday which will then track ENE'wards hitting Northern England.

- I'm also anticipating that more storms will form across the channel then forecast as we have a cyclone directly over the UK but we shall see.

I think it may pass too early in the day here (Southampton) for the exciting stuff however things could change.

Looking forward to the storm reports on this thread.

Edited July 5, 2017 by Quicksilver1989

[Methuselah]

5 minutes ago, Surrey said:

Good luck all, started my new job today couldn't have picked a better week to start. 

 

Some of the charts coming out for tonight and tomorrow are astonishing 

They do indeed, Luke; but, hopefully not too astonishing to be true?

Good luck with the new job, BTW!

[Windblade]

7 minutes ago, Surrey said:

Good luck all, started my new job today couldn't have picked a better week to start. 

 

Some of the charts coming out for tonight and tomorrow are astonishing 

Good luck with the job buddy. 

[BrickFielder]

Tricky to forecast due lots of factors involved. Once thing we should perhaps point out is that early storms across the south may not be rooted in the boundary layer.

See forecast skewt for London.

Further north the picture is a little different.

See forecast skewt for west midlands.

This does not mean that you will not get an intense storm with lots of lightning and rain fall , just that inflow is not in the boundary layer and so the likes of tornadoes would not be on the cards where storms are not based from the boundary layer. High level cloud due to high level moisture may also limit boundary based convection.

 

Having said that there are signs that we should expect significant rain fall from storms developing across the south. The chart that has caught my attention is lightning wizards 0-2km deep convergence chart. This suggests a significant storm passes across the south of the UK with moisture converging at the outflow boundaries.

Lightning wizard explanation of the chart.

   It shows regions of mesoscale ascent, which are sometimes more and sometimes less established  than convergence  of the 10 meter  wind.  It occasionally shows  expanding  rings of deep convergence  when
GFS blows itself  up into a big convective  system.

Any storms forming at outflow boundaries have the ability to develop dangerous characteristics. At the moment there is little suggest this will happen, but it is worth keeping an eye on. It will also be interesting to see where any drier air aloft will be positioned ahead of the approaching cold front.

Typically models move storm development eastwards and downgrade during the day before storms, only to move them slightly back west and upgrade on the day. So do not be surprised if the next couple of runs move every thing eastwards and downgrades the potential. (Similarly at 3 days out the modelling shows things too far west).

Think at the very least somebody should get a good lightning show tomorrow.

 

[Flash bang flash bang etc]

2 minutes ago, Surrey said:

Good luck all, started my new job today couldn't have picked a better week to start. 

 

Some of the charts coming out for tonight and tomorrow are astonishing 

Congrats on the Job :-)

[Windblade]

27 minutes ago, BrickFielder said:

Tricky to forecast due lots of factors involved. Once thing we should perhaps point out is that early storms across the south may not be rooted in the boundary layer.

See forecast skewt for London.

Further north the picture is a little different.

See forecast skewt for west midlands.

This does not mean that you will not get an intense storm with lots of lightning and rain fall , just that inflow is not in the boundary layer and so the likes of tornadoes would not be on the cards where storms are not based from the boundary layer. High level cloud due to high level moisture may also limit boundary based convection.

 

Having said that there are signs that we should expect significant rain fall from storms developing across the south. The chart that has caught my attention is lightning wizards 0-2km deep convergence chart. This suggests a significant storm passes across the south of the UK with moisture converging at the outflow boundaries.

Lightning wizard explanation of the chart.

   It shows regions of mesoscale ascent, which are sometimes more and sometimes less established  than convergence  of the 10 meter  wind.  It occasionally shows  expanding  rings of deep convergence  when
GFS blows itself  up into a big convective  system.

Any storms forming at outflow boundaries have the ability to develop dangerous characteristics. At the moment there is little suggest this will happen, but it is worth keeping an eye on. It will also be interesting to see where any drier air aloft will be positioned ahead of the approaching cold front.

Typically models move storm development eastwards and downgrade during the day before storms, only to move them slightly back west and upgrade on the day. So do not be surprised if the next couple of runs move every thing eastwards and downgrades the potential. (Similarly at 3 days out the modelling shows things too far west).

Think at the very least somebody should get a good lightning show tomorrow.

 

Not sure I understood all that but thanks for the info friend! Due to the nature of the upcoming event, charts and forecasts, as things stand is it possible we may even see a supercell or is that out of the question for this setup? There was talk of cape in the thousands so that is why I'm wondering.

Edited July 5, 2017 by Windblade

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Thu 06 Jul 2017 - 05:59 UTC Fri 07 Jul 2017

ISSUED 21:04 UTC Tue 04 Jul 2017

ISSUED BY: Dan

More detail will be added to this forecast nearer the event. At this stage, most models are in agreement for an area / arc of elevated thunderstorms to drift NE-wards across parts of S + E England during Thursday morning and early afternoon, though the exact northern and western extent (i.e. how much of the Midlands is affected) is subject to some uncertainty.

Assuming sufficient insolation develops behind / around this zone, a few scattered surface-based thunderstorms will be possible on Thursday late afternoon into the evening hours, beginning over NE Wales and these then drifting or developing more towards the NE through the evening.

There is scope for an upgrade to MDT in future updates.

http://www.convectiveweather.co.uk/forecast.php?date=2017-07-06

[dave reid]

Hi all. 

I've cleared the day of work tomorrow, charging the cameras & fueled the van, all ready for my first chase of 2017 WOO-HOO.

Anyone else in the south planning on chasing 

 

[Pat Butcher]

It surprises me that convectiveweather haven't put a SVR around the south-eastern corner of the country - it seems to me that there's absolutely a risk of severe weather occurring there, and I'd expect it to be part of the loop that estofex will inevitably draw around northwestern Europe.

[Morisco123]

4 minutes ago, dave reid said:

Hi all. 

I've cleared the day of work tomorrow, charging the cameras & fueled the van, all ready for my first chase of 2017 WOO-HOO.

Anyone else in the south planning on chasing 

 

Hi Dave, 

 

I have also done the same!  I have not planned where I will be driving too yet though. Any thoughts on where is best to set up first? I am coming from Buckinghamshire

 

 

[TJS1998Tom]

Looks like I may be in for a chance then this time round

[karyo]

Better news from the 6z euro 4, it shows decent shower activity for tomorrow afternoon for north midlands and souther parts of northwest england before moving further east. This is an upgrade to the earlier precipitation chart.

[Derecho]

Latest Met Office forecast downgrades the storms associated with the trough over the South of the UK but upgrades the storms associated with the cold front coming from the West. Keeps chopping and changing.

[Frosty hollows]

It's our school's sport's day in the morning. I'm still no clearer whether or not I should cancel

[tomp456]

Everyone tomorrow on this forum about storms (or lack of)

[Windblade]

5 minutes ago, Frosty hollows said:

It's our school's sport's day in the morning. I'm still no clearer whether or not I should cancel

Tough one. I personally think the early afternoon is more favourable - at least for my area (will be in london tomorrow working during the day). However, I am hoping that the storms hold off until I get home in the evening when I have more time to admire them (plus, I just love home storms. There's just something about seeing the place in a totally different atmosphere to what you're so used to that's just incredible and awe inspiring. I'm like a kid in a sweet shop with home storms!).

Edited July 5, 2017 by Windblade

[staplehurst]

1 minute ago, Windblade said:

Tough one. I personally think the early afternoon is more favourable - at least for my area (will be in london tomorrow working during the day). However, I am hoping that the storms hold off until I get home in the evening when I have more time to admire them (plus, I just love home storms. There's just something about seeing the place in a totally different atmosphere to what you're so used to that's just incredible and awe inspiring. I'm like a kid in a sweet shop with home storms!).

I agree with you there - even when I'm storm chasing in America, I do still get a little jealous of any storms that may be happening back home at the same time. There's something about having a storm on your home soil...

[Harry]

Personally, I'm growing less optimistic based on the latest models. 

To me, the most explosive juice seems to be staying continent side, while yes there'll be instability and some potential triggers it is not on the scale that I think was being indicated a short while ago.

I suspect there will elevated storms across the S/SE tomorrow and some home grown cells on the northern and western edge of the plume, but in between I suspect much of the instability available won't be tapped and we'll be witness to some isolated torrential downpours and maybe the odd isolated intense thunderstorm, but little more widespread than that.

Hopefully I am totally wrong, but I cannot help but interpret the latest models in this way 

[tomp456]

1 minute ago, Harry said:

Personally, I'm growing less optimistic based on the latest models. 

To me, the most explosive juice seems to be staying continent side, while yes there'll be instability and some potential triggers it is not on the scale that I think was being indicated a short while ago.

The usual then lol