Ben Sainsbury

Even ARPEGE still much better than last night. Here's GFS ML CAPE too, unfortunately no MUCAPE charts.

Bit jealous, edging ever closer to the coast. I can't imagine how active tomorrow night may be given how tonight has turned out.

Welcome my friend! We're all friendly, particularly in this chat... unless you don't see a storm that is

Plymouth popping off! Not going to lie a little more lightning than I expected tonight and it's only getting on for half 1. Btw ppn isn't decreasing on landfall, it's just getting sheared ahead of the cells.

Nicely done, good to see someone enjoying the action first hand!

I'm becoming increasingly more impressed with the model output for tomorrow night too. Wednesday if we can see good model agreement/consistency then it could be a very big day.

I'm sure there will be a little more lightning than the detectors are picking up too, as not all IC is detected. Might be a decent show if you're based Plymouth/Torquay. The strong vertical wind shear is definitely playing an important role and to some degree makes up for the lack of instability. These cells have been going for over an hour now, typical lifetime for popcorn storms.

Wow this is a great capture! Cloud tops don't seem too high as expected.

We have a few sferics in the middle of the channel, S of Plymouth. This is where the upper trough is beginning to interact with the Theta-W plume.

I understand where you're coming from, but I just want to clear this up for others. The storms are initiated at an elevated level in the atmosphere, so these aren't exactly being fueled by warmer air on land, with @Lance M making a good point. They are however being fueled by the warm airmass being advected north at 850hPa. Just a minor difference, but is something people can get wrong sometimes. There is some question how far north this warm airmass will reach etc and whether storms can maintain once moving out of this warmer airmass.

Yeah Dan is the best in the business. Exceptional knowledge of the physics behind convection and just great at forecasting. Some of the verification on his forecasts are remarkable.

AROME not showing a huge amount of instability however, that saying it does also seem on its own regarding tomorrow night developments.

The NMM 12z for Sunday night , tomorrow night looks a touch better too.

Agree with the above, Sunday night is looking much better and better model agreement. GFS & NMM so far showing up to 1000J/Kg of CAPE overnight, however DLS looking somewhat on the weak side probably 20-30kts max. Much greater risk of lightning however than tomorrow night. EDIT: Honestly haven't seen this much model discrepancy for imported storms in a good few years now.

ICON & ARPEGE 18z runs both shift west with modelled precipitation for Sat Night, just remains to be seen how much instability builds and therefore the lightning risk.

Admittedly the GFS is relatively poor but both ARPEGE and NMM are decent for coastal areas. I'm still not overly impressed however! I think in this situation if we can see convection developing at an elevated level, along with wind shear supporting greater cloud tops despite limited instability, there should still be some lightning to enjoy but nothing that we haven't seen before. I shared this around on Twitter a few days back, but I'm confident it'll turn out something like this...

Just can't help but bring this up which the GFS is showing for Tuesday! Definite westward shift on this run too. One of the most extreme GFS Precip charts I've seen and it appears to have develop quite an intense squall line, as shown by the large CAPE and relatively strong shear. Will be interesting to look at the skew-t for this one when they update!

I still get the impression this first Saturday night event will favour the SE, but if we have several rounds of storms advected N/NE across the UK we are bound to hit the jackpot with one of them, whether that be elevated overnight storms or homegrown daytime storms.

From what I’ve seen of the models this morning, besides the GFS the high to the east is putting up a big ol fight against any advancements of the low in the Atlantic. Might well turn out to be the perfect scenario for those who prefer storms and not so good for those who want dry and sunny weather.

UKMO has been very consistent the last few days, it's going to have egg on its face if it backtracks now.

GEFS 6z mean shifts the high a touch further east again which is disappointing. Majority of the runs still reach 20'c however, so above average but nothing too exciting. Still a distinct split in the models on Wed 18th and some big rain totals for the same day suggesting of a knife-edge thundery breakdown. I hope for once the models can work back in our favour.

Yeah ECM is not great by any means, unless you prefer just warm, muggy and thundery downpours. It does seem a bit peculiar to me this small system that develops on Sunday night, I don't feel like I see this happen all too often. Regardless it does advect some very warm air across the near continent, if only this could shift a bit further west.

A distinct split in the GFS ensembles today on Thursday 19th, where half keep 850s above 10-11'c and the remaining half drop to sub 6-7'c. Probably a few more ensembles go cooler than staying warm at the moment but pretty much all stay above the 1979-2010 mean. UKMO, GEM & ICON runs this morning still remain good, GFS a lot more unsettled and possibly thundery too. All eyes on the ECM!

You’re not wrong to be honest

Yeah ECM might actually be one of the best thundery runs I've ever seen. Close to mid-teen 850s throughout from late Sunday, approaching 17'c at 850 for SE later in the run. Persistent southerly flow due to high to E, and low to the W. Slack region over the UK, with moisture advection and overriding portion of the jetstream at upper levels. Simply a recipe for severe thunderstorms. Merely an observation of this evenings run and not to be taken as gospel!