Storm/convective Discussion

[Nick F]

Please carry on discussion of the storms today and over next few days ...

Netweather storm forecast for today: http://www.netweather.tv/index.cgi?action=convective;sess=

[dogs32]

thx for the forecast Nick...

Got up at 3.00am.and went straight back to bed....Saw there wasn't much happening...

Deep convection happening down in the Channel just off France in Infra red Sat

Edited June 30, 2009 by dogs32

[Coast]

Blimey, ESTOFEX up early this morning!

Storm Forecast

Valid: Tue 30 Jun 2009 06:00 to Wed 01 Jul 2009 06:00 UTC

Issued: Tue 30 Jun 2009 05:07

Forecaster: VAN DER VELDE

A level 1 was issued for the United Kingdom for excessive rainfall.

SYNOPSIS

Europe is largely free of synoptic scale low and significant high pressure systems, but the airmass is unstable over a large area. A weak upper ridge stretches from the Iberian Peninsula to Scandinavia, while 700 to 300 hPa heights are lower over the Balkan. A frontal system belonging to an Atlantic low will drag over Ireland and Great Britain.

Due to weak wind profiles, shear is less than 10 m/s virtually anywhere, and storms will tend to move very slowly, contributing to pulse type storms with local flash floods, to possibly more excessive convective rain events near persistent convergence zones. Isolated landspouts are also not ruled out.

DISCUSSION

...UK and Ireland...

A nearly saturated airmass with large precipitable water content is advected from the south and CAPE is predicted to develop, mostly over Wales and N England. Storm motion will be relatively slow and oriented along the source of lift. Regenerating convection may therefore keep training along a line for extended periods, leading to flash floods, while large scale models may underestimate precipitation. In Ireland the same moist airmass passes but with almost no instability (elevated), may need to be upgraded later on. The moisture load, weak lapse rates and deep warm cloud depth may reduce electrification.

and why not, with a level 1 over much of the UK?!

UKASF made their forecast last night:

Storm Forecast Issued: 2009-06-29 20:44:00

Valid: 2009-06-30 00:00:00 - 2009-06-30 23:59:00

Regions Affected

Northern England, Wales, N,W+S Midlands, West Country, parts of Southwest England ( much of mainland Scotland, Northern Ireland and remaining areas of Midlands and CS / SW England are included in the WATCH )

Synopsis

High pressure over Scandinavia continues to affect the weather across the UK. A plume of warm and moist air advects northwards out of NW France on Monday evening/night, and is likely to bring scattered showers or elevated thunderstorms to some southwestern/central-southern counties during the early hours of Tuesday morning, moving north into East Wales/W Midlands by dawn. Although these showers may weaken and decay during the morning hours, further thunderstorms are expected to develop within the THUNDERSTORM region on the map. Initiation should be sooner than on Monday due to a more favourable atmosphere and so from early/mid afternoon seems more likely. Slow moving storms are likely to pose a flash flooding risk, and also hail. Most storms should move in a N/NW direction. Some thunderstorms may persist for most of the evening, particularly in northern England, with a low risk of further elevated storms moving across the Channel in the late evening hours.

Are we going to see Carol Kirkwood's 'humdingers' today????

[Faye]

It's just started raining here, but lightly.

[Herefordweather]

Just started to rain here. Every so muggy still.

[dogs32]

rain here fairly heavy...Sky going very dark to my West

[Herefordweather]

Raining ridiculously heavy here currently.

[James M]

Some rain here on and off but nothing too heavy, feeling very humid 18.6C already.

[loopydreamer]

started raining at 6:30 and has been havy at times! still grey out but has stopped rainig now!

i dont think i am going to see a storm today

[Faye]

Raining heavier here now, dark cloud coming from Brockworth, Glos.

[Paul]

As has been requested by a number of people - we've started up a technical discussion to go alongside this thread:

http://www.netweather.tv/forum/index.php?showtopic=55680

[Harry]

Am v surprised at how early this has all kicked off this morning :o

Some fairly lively downpours moving out of France at the moment - whether they'll make the S coast or just stay over N France/fade away will remain to be seen...maybe even drift towards the SE? (just being hopeful!)

As expected, not a lot happening here, very hot already and in to the mid twenties - am hoping I may see some Cb's well off towards the W later - saw some really quite impressive looking towers yesterday afternoon (about 4pm onwards) towards W of London - nice upward motion and quite robust too.

[OldGreggsTundraBoy]

OHW! not looking like there will be any for eastern, SE or coastal areas, have to say looking very good AGAIN for u guys in the west Midlands/ North :o

We in the SE and S have to rely on France and were not getting any, im not sure why in weather terms (if anyone knows i'd like 2 know) but i;'d say France has been a greedy b**ch these last few years!

[A.J]

A very messy radar this morning, the sun is out at the moment, a little bit of surface heating may just pep up the showers over gloucestershire as the push northwards

[Dp1981]

after a little rain this morning sun is peeking out now and again here

[fromey]

very cool and cloudy here, very boring!!!

[Paul R]

Dull and damp at the moment here, been overcast all morning. Hope the clouds start to break pretty soon so the su can get to work on this wet ground.

[Tom Montalbano]

Morning all.

Harry, how did it go at Windsor last night, back any winners? Didnt quite get your storm there but I'm sure you saw some quite stormy skies drifting away to

your NW during the race meeting. That stuff seems to have initiated over the N.Downs S/SW of Croydon mid/late afternoon but only gave slight shower in SW London, the one that clipped Wimbledon.

Not sure we'll see anything over this way today but you never know,Londons' heat island effect could kick start something later but if that happens likely to be only W/NW London at risk but a very small risk indeed I would've thought.

Regards,

Tom.

[Harry]

OHW! not looking like there will be any for eastern, SE or coastal areas, have to say looking very good AGAIN for u guys in the west Midlands/ North

We in the SE and S have to rely on France and were not getting any, im not sure why in weather terms (if anyone knows i'd like 2 know) but i;'d say France has been a greedy b**ch these last few years!

I'd say judging by Brickfielder's analysis on the new technical thread, it is because of the wind direction.

http://www.netweather.tv/forum/uploads/mon...49775_thumb.png

There will probably be some hefty storms over France, though probably won't come our way due to the E/NE windflow. Further W, the windflow is evidently more southerly! As the pressure centre over the North Sea pushes east in the next few days, it will be our turn for hopefully the first decent imports of 2009...hopefully!

Morning all.

Harry, how did it go at Windsor last night, back any winners? Didnt quite get your storm there but I'm sure you saw some quite stormy skies drifting away to

your NW during the race meeting. That stuff seems to have initiated over the N.Downs S/SW of Croydon mid/late afternoon but only gave slight shower in SW London, the one that clipped Wimbledon.

Not sure we'll see anything over this way today but you never know,Londons' heat island effect could kick start something later but if that happens likely to be only W/NW London at risk but a very small risk indeed I would've thought.

Regards,

Tom.

Backed one winner, the same race sadly one horse severely broke his leg - it was a horrific sight for everyone and nasty for the horse. Otherwise, betting and weather wise it was a bad night, lol. Did see as I mentioned some dark skies and some nice towers early on, but the showers that went past to the N were generally quite weak looking. It was baking hot and v v humid other than that.

I don't think in this heat and humidity you can ever really rule out 100%, though obviously the chances are very low. I think thursday and friday could be more interesting for us

Edited June 30, 2009 by Harry

[Nick L]

Wow it really has kicked off this morning, only a few miles to the east of me so I might get on my bike in a bit and take some distant shots.

Is it me or is the NW radar far more pixelated than normal?

Edited June 30, 2009 by nick2702

[Coast]

I'd say judging by Brickfielder's analysis on the new technical thread, it is because of the wind direction.

I think running some of the wind models here, that might be a contributory factor.

[Harry]

Intensifying stuff approaching the S coast at the moment - could be interesting next hour there (W of IoW), looks very nice on NW radar

Edited June 30, 2009 by Harry

[SteveB]

A few heavy showers passing through, but rather overcast and cooler today.

[Kain]

Mornin All

Well I hardly had any sleep last night waiting for the overnight storms that didnt happen lol.

At about 5.15 this morning though it rained pretty good, comming down like stiar rods. I was just egging it to go bang! The I got cramp in the calf of my leg. Ow!

At the moment its abit grey here, which with slow convection down. Interesting to see Estofex has us under a lvl 1 warning though. The met office has said nothing.

Remains to be seen what happens mid to late afternoon, It's going to be then when everything kicks off I'd wager.

Kain

[dogs32]

the batch in the channel looks very heavy now with some sferics being picked up