VillagePlank

The thing is that gravity waves with respect to thunderstorms require nearby thunderstorms. There is a possibility if pulse like storms develop that they hence develop along the line of advection, but in all my time watching weather I have only ever seen this once. And even then, it was a surprise to just about everyone. A possibility, but very rare indeed.

Indeed, infact I think deritus will affect our chances later this evening - we probably need clear skies right up until about an hour before dusk to stand any chance I reckon. Get that surface heating in!!

Yes, particularly at dusk or at dawn. Those surprise thunderstorms just as daylight is breaking.

Maybe. The optimist in me wants another Medway Sausage, but think it's unlikely. Pick another pub then. You don't want that on a day like today

Yeah - Brum looks like the place to be. I wouldn't be ruling out supercell like behaviour, today, in the Birmingham->Manchester area.

Chance of French imports overnight for the Kent, East Sussex etc. Marginal, as the storm will have to become lifted to make it across the channel.

Well, I am forever the optimist. None of the models spat out much for the far SE, but there is still much to play for over the next 48 hours. All sorts of conditional factors come into play, sadly, which ultimately means that it's nowcasting all the way. The potential is there. however.

Very interesting theory about diurnal cycles and thunderstorms (the plantetary battery) and lots in the literature referencing it. The main physical factors seem to indicate the radiative cooling effect (which increases turbulence) and the effect of the temperature reducing on land to a constant temperature out at sea (sea breeze convergence) Of course, if you are in a hilly area there is a greater surface of land than there is to sky, which may well lead to orographic lifting. A hill by the beach on a day like today? Perfect. Sadly, the convection may well start where you are, but that doesn't mean it won't drift off and give someone else the thunderstorm!

Yes, the blue haze is remarkably persistent: the haze being caused by humidity, of course - and limits insolation. All that potential etc. What we need is all of this haze to coelesce into clouds; signs of it starting down here in the SE, but, the question is, is it too late in the day?

Yep, fexofenedine taken. What is it about the Medway Towns and hayfever? I have to take these stupidly strong anti-histamines to control something that simply doesn't need controlling elsewhere in the country. You have my sympathy. The missus and I recently got over a nasty bout of conjunctivitus, and I pointed out to the missus - this what hayfever feels like without pharmaceutical help.

With the windows and doors open, the indoor thermometers, here, are showing 24degC. It's cooler inside than out, and the MetO forecast 22degC for this time. Of note, RH is up to 61% and rising.

Much to my surprise clouds bubbling up to my South, presumably over the Maidstone Greensands. They appear to be sliding north-west in a rather straight line, so I guess an upper trough is trundling through. Didn't expect this, and it wasn't on any of the charts. Of course, instability breeds instability, so perhaps the silly silly temperature of ~33degC may not now have to be reached for things to kick off down here.

I'm not so certain on seeing homegrown t/storms here in the far SE, today. The best numerical data is for Sunday evening which looks interesting for the far SE, A moderately convective environment leading to likely thunderstorms - if it happened during the day. However, given that this happens when the sun has already set, there seems little to expect all of that potential to amount to anything, French imports possible later, today - but this is nowhere near set in stone. As always nowcasting is the key, now.

For us in the far S/E, the most unstable time according to GFS 6z is 6pm, A moderately convective atmosphere leading to isolated severe storms. Sufficient surface heating, perhaps as low as 17degC, allows parcels to go all the way up .... Of course, "isolated" means that everyone else but you will get storms Happy hunting!

The critical thicknesses for 500, and 850 are: 500hPa : 540dm 800hPa : 130dm The critical thickness is where precipitation is equally likely to fall as rain or snow. The lower the values go the higher the chance of snow - the snow line tends to be 122dm at 850hPa and 524dm at 500hPa, but change dependent on location. Clearly, the higher you are above sea level the less height there is too, so some adjustment needs to be for height. Of course, these are rules of thumb, not cast-iron guarantees! If stuff falls out of the sky, and the heights are low enough - both which look to occur over the SE tonight and into the morning - then snow is likely. (I gave up looking at the 850hPa temperature as I've seen rain fall at -8degC and snow fall at 0degC, when the hypothetical temp line is meant to be -5degC)

First BOOM! of the evening heard

Yes, orographic lift, and the urban heat island effect. That all said there does seem to be a trend of storms dying away as they approach from the South towards the North Downs. Just been out to my local observation point and very active out to my west. A long looong way away, and no sound! I would hazard a guess about them being elevated since there's some CIN (c.100 j/kg) to overcome if it were surface based which seems unlikely, I reckon.

Lightning observed due south of me. No rumbles heard. Yet.

Probably best to set up a spreadsheet (like wot I did) rather than try and do this using mental arithmetic!!

(which the geek in me has worked out that that means 15degC DP, lol)

20.9degC and 69% humidity, here.

The more the merrier!!!

Very calm, here, in Rochester. Can see the stars and clouds filtering away North. No sign of anything suggested so far to come!

And lo and behold,