Convective Discussion

[JamieUK]

Thunderstorm here, got really black and just had a few loud rumbles of thunder, a few sferics in there aswell by the looks of the chart, havnt seen a flash myself though.

[chrisbell-nottheweatherman]

Nothing here yet, though the cumulus are getting puffy and tops are getting higher, so it suggests there's some convective potential here.

[gpspete]

just had some heavy rain in Oxford got caught out in it at work the sky went very dark street lights came on clouds looked very storm like but not a single rumble of thunder heard hope it hangs around till I finish work at 2 then hopfully Thor will come out to play

[sunny scunny]

Showers are getting closer to my area, and it's clouding over,but nothing happening yet.

[maidstone weather]

Further to my previous post, I have attached the radar loop, plus where things appear to be heading at the moment.

Discounting potential increase/decrease in strength, the SE have got some downpours with their/our name on - notably some convective stuff which fired up VERY rapidly in the last 10 mins near IoW (red circle)!

I've always said that my location does better from a westerly flow, I hope today is similar to 24th July where we had a cracking storm in the late afternoon.

Basically I need to look at the Brighton area for anything to come my way.

Edited August 21, 2009 by maidstone weather

[Coast]

A big sky full of Altocumulus over Sussex now. All we need is a bit of instability - but I'm not sure its there.....

[Costa Del Fal]

Nothing here yet so far and looks like nothing interesting is happening really yet for here.

[ickledoozer]

Looks like things are kicking off in the Milk 'n' Beans area, shame i'm stuck in Central London!

[we1330]

Afternoon folks, and folkesses ,

Some nice beefy showers passing through here, at the mo it's persisting it down

[chrisbell-nottheweatherman]

Afternoon folks, and folkesses ,

Some nice beefy showers passing through here, at the mo it's persisting it down

With a bit of luck, that might come near me later.

[tuftus]

Looks like things are kicking off in the Milk 'n' Beans area, shame i'm stuck in Central London!

Just rain so far...

[Costa Del Fal]

Patience my fellow Midlander I'll give it 2-3 hours and if nothing significant has developed by then, then maybe it doesn't look too good but for now, let the troughs tap into the CAPE available. At the moment, I have a moderate-heavy shower over me, no lightning, but like I said, give it time.

There is time but its a typical scene to see nothing this way at the minute. Still plenty of time for showers/storms to develop.

[sunny scunny]

Very dark to my west, so im expecting a mega storm in the next 10 minutes

[Costa Del Fal]

Already looks like no more showers are developing in Wales now.

However there is still plenty of time but it doesnt look good. Time to enjoy the sun again!

Edited August 21, 2009 by Blizzards

[karyo]

There is a line of CBs to the west and northwest of Manchester. They seem to be slowly approaching so hopufully it will chuck it down in a bit. Not sure about thunder though...

Karyo

[Cheese Rice]

Strong winds torrentioal rain and i planned on doing the garden

[liambailey09]

The showers heading for me seem to be breaking up on the latest radar runs

[chrisbell-nottheweatherman]

Clouds building here - radar shows showers to my west but, as yet, they are fizzling as they move in this direction.

[Costa Del Fal]

The satellite seems to show nothing developing in Wales now.

Precip is weakening in areas too. What a convective day.

Well, the conditions are there for a small storm, whether it will be the trough or surface heating which will trigger it, is another question. The instability does move East rather quickly so if a storm was to develop in the W Mids, I would expect it to do so in the next 1-2 hours. Radar at the moment showing to downpours East of Hereford but no storms as of yet.

Today was never really a significant storm potential day, just that because August has been so uneventful and I myself haven't seen a proper storm since well, we'll say Jun 10th, that's the reason I've put alot of emphasis on today. Certainly would be nice to have CAPE higher than a 1000j/kg and some nice shear to get storms alot more organised but today hasn't got those important factors.

Yep time is running out fast and tbh i dont think much else is going to happen-well nothing ever started really!

[SteveB]

Just heavy showers passing through here.

If we did get any electrical activity, I would imagine it would be only the odd rumble of thunder here and there.

[Roger J Smith]

Hello, long time no speak ... I must apologize for jumping in here without having had time to read much of this thread or the more technical one, but I have just seen some data that concern me about severe thunderstorm potential especially in the London area this afternoon.

What's really caught my eye today (and as you may know I forecast daily for both the UK and Ireland on other sites) is that temperatures just above the lower elevations at the surface are much, much cooler than is normally the case on an August afternoon. In other words, the air mass is very unstable and despite the perhaps weak synoptics, any small cell could go violently unstable and produce a localized severe storm.

Part of what got me concerned about this was an interesting report in western Ireland that I read elsewhere about a very brief but apparently intense thundershower there at 0600. Then I started to look around at surface obs and you'll notice how chilly it is at places like Brize Norton and Boscombe Down, compared to the 19-21 C type temps at most lower elevations.

So in brief, I would say to watch any developing radar echoes especially in and around greater London where you have the added factors of lift and urban heating, seabreeze convergence zones etc, and it would not surprise me at all if there were some brief F0-1 tornado sightings, as well as large hail and intense lightning. The cells may not be technically supercell because of the low freezing levels and small areal size of cells, but quite severe potentially in any case. Not sure if I can stay on, I've been up all night here on several other projects and it is 0500 for my addled brain.

[chrisbell-nottheweatherman]

Interesting view, Roger. I'm not technically clever at all, but the reports so far seem to show downpours but little electrical activity. Could there be capping at work, or are surface temperatures insufficient as yet?

[sunny scunny]

Torrential rain here

[Coast]

Thanks Roger. Always interesting to have your view (and the other learn-ed NW regulars!). Surface temps are down today with a stiff 16 to 24 mph wind down along the coast where dewpoints have dropped by 5 Dgc and humidity by 20% already this morning.

As I posted earlier, coastal parts of the SE look unlikely (to me) to experience any real activity, but the more central band is where I will be looking at later if things can warm up a bit.

[ickledoozer]

A heavyish shower passed through Central London about 20 minutes ago, got my sparkly shoes wet :-(

Looks like there could be more on the way in the next half hour, drizzling at the moment.

Edited August 21, 2009 by ickledoozer