Storms and Convective discussion - September 2024

[Supacell]

As we say goodbye to summer and hello to Autumn will we be saying hello to some thunderstorms? It is looking possible over the next two days but huge discrepancies between models means trying to accurately predict where any storms will be or if there will be any is difficult. Good luck to those who want to see one, I am one of those people.

Here is a shiny new thread for the month of September which I have started a little early as we are now going to be discussing September when talking about possibilities of storms (unless they crop up before midnight in which case I apologise to August).

Summer has been rather poor from a storm prospective but if the last two years are anything to go by then September can produce some of the best storms of the season. Fingers crossed for the next couple of days and then there are hints of further chances over next weekend.

Keep the discussion going in here. Old thread if you want to reminisce about August is here:

https://community.netweather.tv/topic/100522-storms-and-convective-discussion-august-2024/

 

[CoventryWeather]

@Thundersfor answer on previous page, the storms over Brittany are outflow of the storms near to Bordeaux and Spain. 

Could cause further outflow to the North East later tonight. Might be why the UKV has switched to a fair bit of activity tomorrow. 

[Thunders]

 CoventryWeather ahh alright, thanks!

[Allseasons-Si]

Sfefic's kicking off now east of La Havre,....Hasting's might be a good place later

also noticed a heavy shower that developed east of Peterborough

all seem to be moving N/NNW

Edit: quiet the development on that La Havre storm on the last radar return.

[Thunders]

 Allseasons-Si do you reckon im in a good spot in bexhill?

[East_England_Stormchaser91]

Watching that area over S Lincs. Hopefully might start sparking away shortly! 

[CoventryWeather]

Sferics near that Le Havre cell. That's the one to watch, if you are east of Brighton. 

[Metwatch]

Infrared satellite over France looking pretty nutty tonight and that's slowly heading our way. There is a lot of low cloud over England but that should clear away during the night as warmer air comes in / surface warm front moves away according to UKV's cloudcover charts anyway. Best of luck to all!

Edited August 31 by Metwatch

[Eagle Eye]

Convective Outlook ️ (map coming later because... Can't decide) 

A plume initiated by a longwave trough dipping into the eastern parts of the Bay of Biscay risks a few days of breakdown but with a lot of uncertainty. The strongest moisture of the airmass stays to the south due to the dry air below it that pushes it up being rather limited and weak. That does seem to limit tonight's risk initially to the far SE where there's the risk of a storm pushing across the coast with NE'rn France and Benelux wind flow becoming increeasingly NW'ly flowing and advects energy into the channel, MUCAPE perhaps reaching around 1000 J/KG. But the switch is late at night making the risk of a direct hit weaker due to the storms being quite far east as the the flow begins to change. These risk sporadic lightning for parts of the SE during tonight. However the strong saturation PBL makes the lightning risk weaker.

 

Further west and into the morning hours the switch to SE'ly winds transitions further west and could meet up with SW'lies in the cental south and build storms so where along the SW/central south. However, due to storms over northern France around the same time, the MUCAPE is likely to be used up and makes for a messy evolution that is 50/50 on whether this system does form or not, increasingly leaning towards the convergence not forming. If it does, there's favourable hodograph's and still potential for 1000+ J/KG of MUCAPE and perhaps weaker saturation PBL than the SE overnight risk, for severe thunderstorms to cluster up andor become an MCS and push from the central south NNE into the Midlands by late afternoon and fading into the evening.

 

There's a risk for some severe wind gusts due to the large amount of DCAPE. Along with slow movement allowing for flash flooding risks. Furthermore, the large amount of buoyancy PBL allows some severe hail potential, though it may be limited to around an inch due to the fairly strong low-level shearing in place.

 

There's risks for severe thunderstorms even in the SE overnight risk and there's potential for a few surprises because of the pure amount of moisture and energy. But the large capping and the lack of any real model agreement, means there is little idea about the potential for these to actually happen or not.

[Allseasons-Si]

 Thunders Yep,that's why i mentioned Hasting's

[Sparkiee storm]

18z UKV having a lot of thundery activity for quite a few places and puts a large storm right through the Central Midlands tomorrow afternoon. Will be looking at the models in the morning and deciding then whether its worth to head out or not to get some shots if not storms then at least some cloud scapes. Hopefully tomorrow turns into one of our larger storm days this year. Last few Septembers have been delivering so hopefully it will again this year. I don't know what it is but the atmosphere seems different out there tonight this time compared to most of this year's storm days (or lack of), so whether that's something, remains to be seen.

[Allseasons-Si]

 East_England_Stormchaser91 Yes,keeping an eye on this one myself but i don't hold much hope for it to produce though.

[Julian 777]

 Thunders I can see very faint flashes over the sea low in the South -East horizon ,you should be able to make them out too hopefully

[Wold Topper]

 Eagle Eye is East Yorkshire clear tonight EE, got a marquee to take down in the morning. TIA

[viking_smb]

Looks like a kent clipper 

[Thunders]

i cant see any rflashes yet as building is in the way! Julian 777

 

[Mapantz]

Looks pretty nutz in sw France

My weather app shows storm possibilities tomorrow.

[Allseasons-Si]

 viking_smb It's moving N/NW so no not a Kent clipper

[Electricmumma]

 Thunders visible from bexhill prom

[Electricmumma]

And rumbles heard too.

[Julian 777]

 Electricmumma fingers crossed that you're in a sweet spot there in Bexhill

[Alderc 2.0]

1 minute ago, Electricmumma said:

 

And rumbles heard too.

 

Really? Those storms are 80miles away. Pretty sure thunder, even under favourable conditions can’t be heard from more than 20-30miles away in the case scenario.

[Thunders]

 Alderc 2.0 i thought i heard something a few time too!

 Electricmumma ahh, im behind an old buildig so have to be on my roof to see it roll in, ima get on there then if u can see stuff

[Electricmumma]

 Alderc 2.0 most definitely thunder, been doing this long enough. deep distant rolling thuds that you can feel in the ground.

[Mapantz]

 Allseasons-Si

Quite possibly the rare and elusive 'inverse' Kent clipper?!