Storms and Convective discussion - April 2024

[Eagle Eye]

 Robert1981 not mine but agreed there. 

[UnderTheAnvil]

 Turquoise already writing off the season on the 1st of April? Come on hahahahaha

[Rufus Butterfield]

2nd storm of the year. Died off as it got close but excellent shelf structure and really frequent lightning for a time. Happy with the Timelapse as well. 

[LIGHTNING ACTION]

I think I like it more when they are far away from me

[Rufus Butterfield]

Short video of those mammatus clouds last Friday

[matty40s]

Interesting....

 

[Eagle Eye]

Convective Outlook (Wednesday) ️

 

Showers will develop across NE/E Eng down to majority parts of EA, which may become thundery particularly Hull down to Norwich where an Area Of Interest has been added.

 

Saturated profiles will limit lightning activity, however a few strikes may be seen.

[Robert1981]

 Eagle Eye looks good for my area

[Eagle Eye]

Mini-forecast for Wednesday night using both main Swiss models and the AROME and WRF. 

On the western edge of an advected theta-E envelope, Wednesday night has the potential for some thunderstorms along the south coast. Strongest Theta-E of the year it appears is very possible. 

3CAPE looks to be very strong for night, mostly surface based developments, but perhaps a mix between the two. France surface based storms won't be an issue, and nor does the channel seem to be, as they initiate over the channel with that surface energy. Perhaps pulsing forwards with different bands of showers andor storms rather than specific ones till they hit the coast. 

This allows for cells to form through the channel and along the coast for the south coast. Mainly in the southwest but does look to extend eastwards throughout the night. They may be parallel to the coast, with the Theta-E envelope or perpendicular to it, but I suspect that developing parallel would allow for better use of moisture. Alternatively, could mean that it stays in higher saturation and lightning is more limited as the moisture-temperature gradient is potentially lower. 

Buoyancy is still varied with different models. You can especially see the limit of the almost dryline to the north with developments to the south of that. The lifting isn't really an issue here. 

Saturation is quite high and the column profiling here based off these models looks quite poor away from the southwest and that may significantly limit lightning. Then the other model pushes the drier air over Wales further southeast and that's the better scenario for lightning potential, also may allow a clearing more of the rain thats likely to push earlier. 

Deep-layer shear is stronger over the SE and central south, with very little over the southwest. Supercellular potential seems unlikely to be honest. Even away from the southwest. 

Shearing at the low-levels is a completely different story though, the coastal difference and friction may allow for some spin-ups to form depending on the 3CAPE and vorticity as well. 

Hence the potential for rotation is there. Clearly it's not that significant based off how much could potentially go towards rotation though. Likely not much hooking in the low-level wind profiles then. Some tornadic potential there. 

Lapse-rates in the SW are also on for hail potential. Though the shearing profiling can be very lowering of that potential for hail. Given previous events this year, that seems to be less of a contentious issue than I would've thought. 

AROME is more of a different approach with it moving more directly west to east. Still a fairly decent event for early storm season on the AROME though and maybe good signs that we're getting towards proper plume potential where it can make it across the channel with enough energy backing it. 

Profiles are quite highly saturated, but the mid-levels may lose some saturation and in the hail growth zone as well. That'll lead to better conditions for hail growth and also the downdraft to be stronger, maybe leading to surface wind gusts, but also, the hail more directly forced downwards, once growth occurs, especially best if the downdraft and updraft seperate strongly. Hail may get to near severe or severe status based off that. 

[ChannelThunder]

 Eagle Eye thanks for the details. I hadn't even paid attention to the fact there is a storm risk tonight, just assumed it was your bog-standard showery Atlantic front!

[Eagle Eye]

 ChannelThunder

Yeah problem is that it's beginning to look very messy now as deep-layer shear increases on the models. That's leading to a lot less storms on the models, especially further east. But, we'll see what happens tonight. 

However, look at the UKV. 

Edited April 3 by Eagle Eye

[Cain]

Possibility in the early hours if things are right and don’t change drastically 

Edited April 3 by Cain

[Robert1981]

 Eagle Eye I see this morning on wx charts the Cape was not as much as yesterday models I don't no any of the models like u do. 

[Thunderspotter]

 Eagle Eye A very in-depth forecast! I wasn't expecting to be on here today, just woke up and decided to have a quick look - to be met with this! 
 

Typical that the highest risk (for me at least) seems to be in the early morning hours of tomorrow, as I have in-school revision taking place that day...

Edited April 3 by Thunderspotter

[Robert1981]

Some heavy showers with dark skies around Norfolk this afternoon but unfortunately couldn't get any pictures.

[Cain]

With some luck there’s still a chance of something in the early hours 

[LIGHTNING ACTION]

there were some cool skies to my south again, sadly not producing lightning but had a yellowish tint

 

[Robert1981]

 LIGHTNING ACTION I had similar skies here in Norfolk this afternoon. 

[viking_smb]

 Eagle Eye current UKV has reduced this further

[Cain]

So a down grade over night then by seems of things ?

[viking_smb]

yes

[viking_smb]

there is a storm in the western approaches according to blitzortung, but going from the track of the previous strikes it will be going though the english channel

[Thunders]

keeping an eye on this to see if we can get some storm form within this mass, i thinking that would be a good sign that there is a possibility for us on the coast

[ChannelThunder]

 viking_smb shows as a nice round lump on satellite. 

Current trajectory swings it along channel coasts somewhere I'd say, from analysing the sat. loop & Blitz

[ChannelThunder]

As a caveat to the above, it's of course still hundreds of miles away! I shouldn't really try to predict its path over such a long distance, especially given it'll likely die off and/or be replaced by sister storms later on. Single thunderstorms like that rarely last beyond a couple of hours!