Storms and Convective discussion - 1st August 2022 onwards

[The Tall Weatherman]

@Tempest Depends if the cap brakes on Monday, the storms may struggle to lift off where you are.

[Ben Sainsbury]

Just thought I'd take a little bit of a deeper look into the Thunderstorm Risk for Sunday/Early Next Week.

Saturday night would expect a few elevated thunderstorms to approach S Ireland/far SW England but nothing too much of note at this point. 

Sunday we see some quite large CAPE developing across Ireland and less so for N England/Scotland. I'd expect a combination of strong surface heating/convergence zone/orographic lifting to initiate scattered thunderstorms, possibly strong/severe at times given modest DLS over Ireland.

 

By Sunday night, as the low gradually drifts a touch eastwards, I would expect storms to become increasingly elevated as the boundary layer cools with some impressive lightning shows right across the Irish Sea and up towards NW England/Scotland, given the magnitude of MUCAPE.

Monday looks to have a more widespread thunderstorm risk, with large instability (for UK standards). With a slack low sat right over the UK, wind shear will likely be weak, however given the magnitude of instability, some strong thunderstorms are likely to develop again; this time across much of England, Wales and into S Scotland. Shear across NW England/N Wales is less weak, so some organisation is possible for a time here. Storms becoming increasingly elevated overnight.

The last day I'm going to cover is Tuesday given there are still uncertainties on the positioning of the low near the UK. However, I would expect a similar day to Monday albeit the risk transferring a bit further south. Strong thunderstorms developing once again, however as the low pulls south there are some indications that modest wind shear will exist across C/E England. Assuming this (UKV) to be the case, then multicellular development is possible with the potential to upscale into a homegrown MCS into the evening. Flash flooding, prolific lightning and relatively large hail are the likely risks. But at this stage, this is all speculation and to be taken with a large pinch of salt.

That saying, there is relatively good agreement between the models for Monday at least to be a fairly active day, some a close eye is being kept on model developments over the next few days.

Edited August 11, 2022 by Ben Sainsbury

[viking_smb]

be interesting to hear what dan thinks of this

over on the model thread its been pointed out that UKV follows the UKM model, and the GFS/ECM have produced less unstable outcomes. 

 

lets see what happens on this.

[Mapantz]

Marginal instability showing for here on the GFS for Monday, but also a strong cap. Much better for those further inland though.

[Tempest]

9 hours ago, The Tall Weatherman said:

@Tempest Depends if the cap brakes on Monday, the storms may struggle to lift off where you are.

Ahh well, I’ll just have to cross my fingers 

[WeatherArc]

Some Interesting soundings from the GFS 18z run for tuesday showing a MRGL tornado risk with around 900 j/kg of cape for East Anglia alongside supercell composites of 4. While we are still 4 days away there is the possibility of a few strong storms for both monday and tuesday across central and southern England.

Edited August 12, 2022 by WeatherArc

[Sparkiee storm]

UKV 03z remains with the storm theme and even amps up the activity a little more, with things starting to destabilise on Sunday afternoon/evening with scattered showers/thunderstorms breaking out over England/East Wales and more so Scotland, NW England gets a chance overnight Sunday, Then Monday looks very interesting with potentially intense thunderstorms over England of Wales and that risk then remains until overnight Tuesday into Wednesday, by this time most of the country has seen rain, including the SE. Still not to be taken literally though, but the theme seems good enough to be confident that thunderstorms and intense downpours will develop.

 

Edited August 12, 2022 by Sparkiee storm

[Dangerous55019]

Morning o’fellow storm starved folk of Netweather, I see that the U.K. Meto has just issued a thunderstorm warning for Monday! 🌩⛈
 

Obviously it’s a long way off, but it’s an encouraging start.

[Mapantz]

I never find a MetOffice thunderstorm warning encouraging lol

[Methuselah]

Just now, Mapantz said:

I never find a MetOffice thunderstorm warning encouraging lol

Me neither. And a BBC one even less!

[Dami]

well blow me, i've got a yellow for thunder on Monday, so guess that won't happen!

[The Tall Weatherman]

Guess what ! I’m going on holiday, I wonder when ? TUESDAY (the big day)

        

[minus10]

39 minutes ago, Dangerous55019 said:

Morning o’fellow storm starved folk of Netweather, I see that the U.K. Meto has just issued a thunderstorm warning for Monday! 🌩⛈
 

Obviously it’s a long way off, but it’s an encouraging start.

Certainly not encouraging for the south east ...no warning as usual...

Edited August 12, 2022 by minus10

[Eagle Eye]

39 minutes ago, Dangerous55019 said:

Morning o’fellow storm starved folk of Netweather, I see that the U.K. Meto has just issued a thunderstorm warning for Monday! 🌩⛈
 

Obviously it’s a long way off, but it’s an encouraging start.

I'm not in it apparently (when I land back at Gatwick anyway) so thats a nailed on Storm for me then

2 minutes ago, minus10 said:

Certainly not encouraging for the south east ...no warning as usual...

I'd argue that's quite encouraging based off previous events 

[Sunny76]

Hope it’s a supercell storm. 

[snow raven]

19 minutes ago, minus10 said:

Certainly not encouraging for the south east ...no warning as usual...

I wouldn't worry, a MET Office warning is usually the kiss of death for anything to actually happen.  Plus Monday is a few days away and always subject to change.

[sheikhy]

1 hour ago, Mapantz said:

I never find a MetOffice thunderstorm warning encouraging lol

Ah well thats means no storms or even rain now!!!

[camturbo]

Let's just see nearer the time and see what Dan says or if estofex get on board or indeed looking out the window on the day

[Tom Quintavalle]

3 hours ago, snow raven said:

I wouldn't worry, a MET Office warning is usually the kiss of death for anything to actually happen.  Plus Monday is a few days away and always subject to change.

Hi Leeanne,

And if those wildfires break out over your way again, as they did the other Evening. Do you think you could extinguish the flames, before they make it over to Lee, on that East.wind.

Cheers,

Tom.  

[ChannelThunder]

Not sure how much to trust the UKV given it has storms spreading in from the southwest from the secondary low on Tues night, whereas other models are already removing unstable conditions away from the east at that point with a northerly fetch. I suspect the 15z run may show something completely different.

[viking_smb]

17 minutes ago, ResonantChannelThunder said:

Not sure how much to trust the UKV given it has storms spreading in from the southwest from the secondary low on Tues night, whereas other models are already removing unstable conditions away from the east at that point with a northerly fetch. I suspect the 15z run may show something completely different.

You have a point lance, regarding sun eve/night, i think it will be a northern event, and the daytime monday will be england/wales, as according to met office warning the storms will clear during the eve/night hours on monday night, 

[A Face like Thunder]

A separate yellow warning for thunderstorms covering parts of Scotland and NI on Sunday.

[Ben Sainsbury]

Due to the highly unstable and relatively moist atmopshere, storms could pop up almost anywhere from Sunday night to Tuesday night in my opinion. Just have to hope any crud from elevated thunderstorms doesn't inhibit any strong/severe convection the following day.

Edited August 12, 2022 by DiagonalRedLine
Removing empty space under post

[Methuselah]

1 hour ago, Ben Sainsbury said:

Due to the highly unstable and relatively moist atmopshere, storms could pop up almost anywhere from Sunday night to Tuesday night in my opinion. Just have to hope any crud from elevated thunderstorms doesn't inhibit any strong/severe convection the following day.

From my perspective, Ben, we need rain. And I really couldn't care less whether its source is elevated or not!

 

Edited August 12, 2022 by DiagonalRedLine
Removing empty space under post

[The Tall Weatherman]

Starting to get real intriguing for Monday and Tuesday based on the new 12z runs. Definitely room for change but the situation is definitely getting closer. Monday looking like a big day with (<2000) cape building across central and northern Wales moving east as the day goes on, the storms might become organised for a time as the afternoon ends around parts of central/western England . The storms should rumble away by Tuesday morning and quickly during the morning hours (<2000) cape should interact with the very warm and humid, perhaps sheared environment. Central south England and eastern England should see the strongest storms of day but widely across England scattered storm can be expected.