Storms and convective discussion - 1st April 2021 onwards

[sheikhy]

1 hour ago, Josh Rubio said:

Pretty much right over Leicester, that orange blob. Typical as I have to head out around that time too ️

And perfect for my food delivery rounds in leicester as much as im not a fan of rain!!

[Turquoise]

all the runs are indicating that this will be a classic Kent clipper at best tomorrow night. Thursday morning into afternoon looks a bit better for more SE and SC England

[Summer Sun]

Day 2 Convective Outlook

VALID 06:00 UTC Wed 16 Jun 2021 - 05:59 UTC Thu 17 Jun 2021

ISSUED 13:16 UTC Tue 15 Jun 2021

ISSUED BY: Dan

An upper trough over the North Atlantic will extend southwards through Tuesday and Wednesday, merging with an upper low to the west of Iberia. The net result is the mid/upper-level flow will become increasingly backed with time, allowing advection of a high Theta-W plume over western Europe into SE Britain by Wednesday evening. Forecast profiles reveal a marked elevated mixed layer (EML) with substantial moistening of the mid/upper levels as Wednesday evening progresses. A minor shortwave embedded within the SW-ly flow aloft is likely to coincide with isentropic upglide to aid forced ascent and generate deep convection rooted above the boundary layer.

The most likely scenario is elevated thunderstorms will erupt along the leading edge of the EML during Wednesday evening and night, initially across the English Channel / NW France, tracking northeastwards across CS / SE England and then across the Home Counties and East Anglia during the remainder of the night. It is possible that thunderstorms could develop as far west as Dorset initially, but with time lightning activity may become progressively confined to areas further to the east (e.g. SE England and coastal East Anglia, as an extreme example) along the leading edge of the main continental Theta-W plume, as the atmosphere becomes worked over and modified by convection further west. The main hazards will be lightning and locally large rainfall totals giving the risk of surface water flooding. However, inverted-V profiles suggest the potential for strong gusts of wind, potentially as high as 40-50mph locally from the strongest cells.

 

This forecast will likely be updated with additional information over the coming days, including the inclusion of higher threat levels, as confidence in the forecast evolution increases.

http://convectiveweather.co.uk/forecast.php?date=2021-06-16

 

[Met4Cast]

EURO4 & ARPEGE are likely too far west, conversely, AROME I suspect is too far east. 

We’re likely looking at more than just a “Kent clipper” here, but pinning exact locations is still rather difficult. 

UKV seems to be going for more of a middle ground, I’d favour that for the time being. 

[chapmanslade]

36 minutes ago, Azuremoon2 said:

all the runs are indicating that this will be a classic Kent clipper at best tomorrow night. Thursday morning into afternoon looks a bit better for more SE and SC England

Are they ? 

[ChannelThunder]

Once again UKV is wanting to make friends with a lot of us who are a tiny bit further west...

[camturbo]

Let's hope that's it's right eh!!!

[BrickFielder]

It is still not exactly clear what will happen with regards to Storms, but it is starting to look like two different storm potentials. One around 9pm to Midnight Wednesday for the very far south east and perhaps early hours of Thursday for the south, midlands running up to parts of the north west. Neither scenario looks like being surface based so more electrical than wet. There may be a point across the midlands around 8am where storms change to surface based at the leading edge of storms.

 

Forecast SkewT's show very little convective energy so have to assume storms build from upper cooling and vorticity.  The wind field does look interesting but probably cannot be utilized not that I am placing much faith n the forecast skewT at the moment.

Still to far out for suggest exactly where and when storms will occur , but I am not ruling out anywhere south of the front, nor that parts of the north get notable storms.

[Eagle Eye]

Anybody notice the clouds at the opening ceremony of the European Championships?

[Harry]

50 minutes ago, BrickFielder said:

It is still not exactly clear what will happen with regards to Storms, but it is starting to look like two different storm potentials. One around 9pm to Midnight Wednesday for the very far south east and perhaps early hours of Thursday for the south, midlands running up to parts of the north west. Neither scenario looks like being surface based so more electrical than wet. There may be a point across the midlands around 8am where storms change to surface based at the leading edge of storms.

 

Forecast SkewT's show very little convective energy so have to assume storms build from upper cooling and vorticity.  The wind field does look interesting but probably cannot be utilized not that I am placing much faith n the forecast skewT at the moment.

Still to far out for suggest exactly where and when storms will occur , but I am not ruling out anywhere south of the front, nor that parts of the north get notable storms.

“Very far SE” reference is a bit depressing but the lightning wizard suggests (on its current run) I might still get some action  

Here is for a westward nudge so that many more can benefit too!

 

[East_England_Stormchaser91]

Latest AROME has backed west slightly, to include most of the SE and East Anglia. Hoping the EURO4 maintains the same theme. Still not looking bad! 

[Mapantz]

Just having a gander at the NetWx SR model.. plenty of mixed layer cape in Northern France tomorrow evening, but as it trundles towards the UK, it starts to dissipate. I take from that, elevated lightning moving across the channel to Southern coasts, and then dissipating.

I don't hold much hope for myself, other than some rain.

[Harry]

4 minutes ago, Mapantz said:

Just having a gander at the NetWx SR model.. plenty of mixed layer cape in Northern France tomorrow evening, but as it trundles towards the UK, it starts to dissipate. I take from that, elevated lightning moving across the channel to Southern coasts, and then dissipating.

I don't hold much hope for myself, other than some rain.

WRF NMM 5KM in agreement with that trend. Some MUCAPE across the far SE for a brief time, but it has definitely scaled back CAPE and convective precipitation. Not a positive trend.

[Harry]

Early Estofex forecast for Thursday 06z to Friday 06z.

They have not yet issued a forecast for tomorrow night however.

Edited June 15, 2021 by Harry

[Guest]

23 minutes ago, Harry said:

Early Estofex forecast for Thursday 06z to Friday 06z.

They have not yet issued a forecast for tomorrow night however.

Bit worrying TBH.

[StormLoser]

Estofex. Yep. Kent Clipper. I've lived through enough disappointment to feel this is likely to be another bust. 

I only pray I am wrong, and that I do get to see some action around my area as Dan forecasts.

Then I can worry about my house being struck by lightning.      Keeps the mind occupied and requires a few beers (while watching) to keep calm! 

[Met4Cast]

We don't need CAPE across the UK, these are imports, not home grown thunderstorms. There's plenty of instability across France and that's where storms will initiate and develop, initially surface based before becoming increasingly elevated. 

As they move northwards within the high theta-e & fairly steep mid-level lapse rates they'll become increasingly elevated, rather negating the need for high CAPE values over the UK itself.

Reasonable shear & vertical wind profiles will be enough to sustain thunderstorms across the channel and into southern/SE England, wherever they make landfall. 

All looking fine, no changes. Exactly where they're going to hit still needs answering though, huge model variation continues within the 12z outputs. 

 

[Harry]

14 minutes ago, Met4Cast said:

We don't need CAPE across the UK, these are imports, not home grown thunderstorms. There's plenty of instability across France and that's where storms will initiate and develop, initially surface based before becoming increasingly elevated. 

As they move northwards within the high theta-e & fairly steep mid-level lapse rates they'll become increasingly elevated, rather negating the need for high CAPE values over the UK itself.

Reasonable shear & vertical wind profiles will be enough to sustain thunderstorms across the channel and into southern/SE England, wherever they make landfall. 

All looking fine, no changes. Exactly where they're going to hit still needs answering though, huge model variation continues within the 12z outputs. 

 

I’ll hold you to that @Met4Cast

I have seldom seen an occasion where storms (surface or elevated) move into a Cape-less environment and sustain electrics. 
 

Let us see

[Met4Cast]

1 minute ago, Harry said:

I’ll hold you to that @Met4Cast

I have seldom seen an occasion where storms (surface or elevated) move into a Cape-less environment and sustain electrics. 
 

Let us see

Ha, obviously no guarantees! But I'm not seeing the need to panic just yet.

[East_England_Stormchaser91]

34 minutes ago, Alderc said:

Bit worrying TBH.

Not really. I’ve seen severe storms in the Balearics without any warning from  them at all, and have been under a level 2 and have seen next to nothing! 

Even if you are in the orange, there’s still only a 5% possibility of verification of severe weather from 40km of a given coordinate. It really isn’t a big chance relatively speaking! 

[Ben Sainsbury]

UKV 15z run is on steroids.

Edited June 15, 2021 by Ben Sainsbury

[SilverWolf]

3 minutes ago, Ben Sainsbury said:

UKV 15z run is on steroids.

Thanks, I guess potentially least likely outcome I’ve read on this thread, but being in Gloucestershire I’ll take this one!  

[sheikhy]

3 minutes ago, Ben Sainsbury said:

UKV 15z run is on steroids.

Forget the south east that frikkin gives the west midlands and northern england the light show/battering!!!!

[Lauren]

Here we go guys! On the rollercoaster we go!

[Jamie M]

Talk about a corker eh

7 minutes ago, Ben Sainsbury said:

UKV 15z run is on steroids.