Convective / Storm Chat And Discussion

[bybo1999]

Looks like things starting to move in N France , just gotta hope it can hold together as it crosses the channel into the SE

[Muffelchen]

Way up North here but the weather is interesting nonetheless.

Has now reached the dizzy heights of 17.6°C here with strong insolation, in spite of the wind. Of more interest are the low cumulus fractus clouds that are being blown along in a force 4 ENE wind at the surface. However, high up it is a different story. Here the cirrus clouds are moving due E, in other words a West wind. Quite a lot of wind shear about then if there is enough moisture and daytime heating to set anything off. If surface wind veers and the DPs increase (current humidity only 56%) then you never know. Warm wind over the Humber does amazing thigs but at the mo it is off the N Sea and we all know what that means.

Not confident at all, unless the surface wind direction changes...

[Rustynailer]

http://andvari.vedur.is/athuganir/eldingar/ Here is the radar we/us use for those lovely Volcanoes in Iceland. I don't think all todays strikes are necessarily accurate regarding position, but they are accurate as strikes and noises for a particular time I (do) think. Anyway just another interesting angle of observation.

Nice to feel rain, just been to the Old gaffers yacht festival, pirates are sacking Yarmouth at the moment... the light rain is pleasant compared to yesterdays 28C muggy dry arrid desert affair, it really felt like thunder yesterday later on. Perhaps we will have better luck today

[VillagePlank]

Firstly, let's look at the theta-e (equivalent potential values) This is a combination of both temperature and moisture, so the higher the better, and about 700hPa is probably the best one to look at.

This first image on the left, is the theta-e for about now (15z) but note that the 45C line moves to cover the entire SE by midnight. Theta-e has some good properties such that thunderstorms tend to propagate into areas of high theta-e from lower areas; this means that, tonight, we should expect to see some movement into the 45C theta-e ridge - those storms on the continent will move N/NW.

Next, we need to look at the state of the atmosphere - we want to know if an area is going to go upwards rather than sink. The vertical velocity charts are pretty handy as they show how much the atmosphere is going to move (up or down) per hour in Mb:

Note the area of buoyant atmosphere moving NE into the SE and E Anglia. This is the likely area of storm location. Also on the furthest right chart note the corridor of upwardly mobile air straight from the continent into the SE keeping with the theta e ridge at the same time.

As a check to make sure we're not seeing things, that corridor is highlighted in the precip charts:

Now for the bad news: Theta-W (wet bulb potential) - we really want this to be >18C, and it isn't:

This, then, combined with a forecast CAPE of next to nothing, and very marginal LI (amongst other parameters) implies heavy rain with a possibility of thunderstorms where a chunk of suitable air has survived the channel trip.

Good for the much needed rain, and defo a radar + beer evening. I wouldn't put any money on fireworks, but would understand if some isolated spots in the SE, E Anglia saw some sferics, tonight.

Edited June 5, 2011 by Sparticle

[tomp456]

left trouser leging it down in worthing..... RIP storm potential for tonight.

[VillagePlank]

left trouser leging it down in worthing..... RIP storm potential for tonight.

It's not about surface heating, today; it's about atmospheric state - it is marginal, though. The trigger is a weak change in atmospheric profile enabling lift to occur, as seen by the closeness of the theta-e bars:

Worthing is definitely in the mixing pot, but would suggest further E and NE have better chances after dusk.

Edited June 5, 2011 by Sparticle

[knocker]

It's not about surface heating, today; it's about atmospheric state - it is marginal, though. The trigger is the a weak change in atmospheric profile enabling lift to occur, as seen by the closeness of the theta-e bars:

Worthing is definitely in the mixing pot, but would suggest further E and NE have better chances.

I must admit I'm not sure I follow that. Anyway the two distinct air masses that are effecting southern Enland and northern France can be seen on the midday ascents at Hurstmonceux and Trappes. If the METO Invent forecast is correct the SE should get some much needed rain in the next 15 hours or so.

Edited June 5, 2011 by weather ship

[MP-R]

Doesnt feel overly cold here MPR - if anything slightly muggy albeit cooler than yesterday

Hi. I'll hasten to add that I'm now back in Bristol. I will change my avatar haha.

[Raidan]

Stayed up until 5 o'clock this morning hopeing for something but nothing happened,Woke up around 1.30 this afternoon to find it had rained big time lots of surface water around,A few people i spoke to said they didn't see any lightning or hear thunder so hopefully i didn't miss anything,One thing that is bugging me is that the Iceland sferics map wont update for me but is for others,I have the same image this afternoon as i did 11 o'clock lastnight just 1 sferic on south coast,any suggestions?

[VillagePlank]

I must admit I'm not sure I follow that. Anyway the two distinct air masses that are effecting southern Enland and northern France can be seen on the midday ascents at hurstmonceux and trappes. If the METO Invent forecast is correct the SE should get some much needed rain in the next 15 hours or so.

I think this is one where we want to take a close look at the 12z ... t/storm forecasting with no CAPE, and no LI is very (very) tricky.

[Lauren]

Nice bit of rain here. Nothing heavy, but consistent.

[Dean E]

Good Afternoon!

Had a great lightshow in the channel last night, with one elevated storm striking every 2 to 3 seconds! Sadly, it only made it as far as Beachy Head around Eastbourne, as I the electrification died a death. Was a great show though with a fantastic cloud structure!

I seem to be in a constant hole with this precipitation with only a 5 minute light drizzle shower!

I'm also keeping a very close eye on the Northern Coast of France, aprrox from Paris to Calais as this area appears to be showing some development from some surface heat.

Will keep an eye on all this

[knocker]

I think this is one where we want to take a close look at the 12z ... t/storm forecasting with no CAPE, and no LI is very (very) tricky.

Well here's the 12z surface chart.

[Biggin]

Nice bit of rain here. Nothing heavy, but consistent.

Me too Lauren well welcome, tho looks like a dry period coming up for us in an hour on the radar http://www.raintoday.co.uk/ With some heavier stuff coming later hopefully.

[Adi F]

I think this is one where we want to take a close look at the 12z ... t/storm forecasting with no CAPE, and no LI is very (very) tricky.

In deed. I am waiting for the 12z to come out to see if it is worth making the 120 mile round trip to Beachy Head. I don't want to make the same mistake as last night an stay local to see where the storms would come ashore. I got a good show but i left it too late to move to Brighton I should have just headed to Beachy Head when I decided to go and chase!

Oh well thats the best part of the chase trying to get the right location. And let be honest the storms have not been overly great recently!

[VillagePlank]

Oh well thats the best part of the chase trying to get the right location. And let be honest the storms have not been overly great recently!

I don't think that even if storms do form tonight that they will be great, either

Edited June 5, 2011 by Sparticle

[Adi F]

I think you will be right!

[knocker]

Most of the storms at the moment appear to be in Germany where there is an area of low pressure. The 700mb wind barbs for Europe at 12z.

[VillagePlank]

Looks to me that E Anglia are going to miss out with all but the lightest of showers, tonight. Best placed area is now Isle of Wight to N Kent, and everywhere SE of that. More later.

[paul m]

The continent looks quieter than yesterday but i suppose there is time yet.

[Muffelchen]

OK have avoided looking at the radar, however, observations here are interesting.

Surface wind has veered SE whilst upper wind haas backed SW and there is Accas streaming in from this direction. Temp 13.9°C and humidity is 64%.

Probabaly means nothig this far North but interestingly nonetheless.

[lewisosd]

With this SE movement, East Anglia may be in for some rain finally! Possiblility of a storm too? Fingers x'd!

[Cableguy]

so where's the forecast heavy rain for the SE coming from? Light rain all day here today, awful dull weather.

[Biggin]

Have had 2-3 hours of medium heavy rain, thought it was sposed to rain later?? Oh Well great for the garden.

[95 Degrees]

so where's the forecast heavy rain for the SE coming from? Light rain all day here today, awful dull weather.

Also not sure about the heavy rain tonight, I'd imagine France is where the source is before heading over the channel to us, there's some organised rain moving North in N France just w of Chartres but is veering NE and will likely miss the SE, is something expected to just pop up in the channel?

Hope it doesn't rain much though, no point without the thunder unless it's really heavy, and like the dry look/feel which I have gotten used to. Good to see the plants getting some needed moisture though, but that'll do for me.