Convective Weather Discussion UK

[tomp456]

Too far away I think:

It just died...

"29/03/2011 17:06:29 No thunderstorms detected NexStorm V1.8.0.7025:PCI"

actually i take that back.. :S

Edited March 29, 2011 by tomp456

[ZONE 51]

Thundery Downpours moving in the green arrowed directions

[NL]

Thundery Downpours moving in the green arrowed directions

I think you must be new to watching storms coming in from across the channel, as all the lads and lasses from the SE will tell you the 'cold' waters of the channel will eat them up and all you'll be left with is a few heavy showers.. I do hope they can stay together but I'm very doubtful as they've been trying for awhile now and have been and continue to decay as can be seen on the NW5 min radar.

[Jane Louise]

Nothing happened here... what's new lol A couple spots of rain that's all! the Met Office had forecast heavy rain for Glos this afternoon but I don't think it happened anywhere in Glos grrrrrr. Better luck next time I say and good luck to those near the South coast. :winky:

[ZONE 51]

I think you must be new to watching storms coming in from across the channel, as all the lads and lasses from the SE will tell you the 'cold' waters of the channel will eat them up and all you'll be left with is a few heavy showers.. I do hope they can stay together but I'm very doubtful as they've been trying for awhile now and have been and continue to decay as can be seen on the NW5 min radar.

i know! what i ment was they are thundery over france, but i don't like saying their decay..i leave that part to others!!

i like to not go below the line of complete disapointment, if i was totally sure they would not be thundery i would say , but im not sure!!

[tomp456]

I think you must be new to watching storms coming in from across the channel, as all the lads and lasses from the SE will tell you the 'cold' waters of the channel will eat them up and all you'll be left with is a few heavy showers.. I do hope they can stay together but I'm very doubtful as they've been trying for awhile now and have been and continue to decay as can be seen on the NW5 min radar.

i live along the south coast..directly in the path of one of those were to be thunderstorms.

nothing is happening.

[Stormyking]

If the Storms are Elevated then it doesn't matter if the waters are cold, surface based stuff it will die though, its what my freind has taught me and he is very clever at the weather and storms, trust me

[NL]

I am thoroughly aware of the the thermodynamics of thunderstorms and how 'relative' cold sea temperatures can hinder or even enhance development, trust me living by the coast for almost 50yrs is testament to that, but in this case it is clear that these storms aren't elevated and are surface based. I know even surface based storms can develop over 'coolish' seas if there are other elements involved such as directional shear etc but in this case clearly not evident so in my eyes only one outcome.... No storms...

[NL]

No worries Wx09..lol, Actually tis' a very good point you made perhaps I should have explained why I thought the channel was killing off storms instead of just saying what I did, thanks for your input and setting the record straight...

Some pretty hefty rainfall showing up over the NW especially around Carlisle at the moment.

[Thundery wintry showers]

I can see why the minor conflict has arisen- the scenario of elevated storms tracking across the sea and keeping some of their intensity is extremely rare near the east coast of Scotland and NE England, because the track over the sea is longer and the SSTs are significantly lower than they are in the English Channel. I remember the 22nd June 2007 when thunderstorms intensified over the North York Moors but fizzled out over the North Sea as they headed NNW towards Tyne and Wear, leaving the Tyne and Wear coast with a patch of high cloud from the remains of a cumulonimbus anvil- and then once the cloud got more than 5 miles inland another cumulonimbus formed and took its place!

The shower clouds did reach Norwich in the end but only produced a little light rain- indeed for most of mainland Britain it's been a pretty disappointing day convection wise, although some parts have caught a couple of heavy showers and the odd sferic.

[Nick F]

Sunday still showing a widespread potential for some convection, as an Atlantic trough, with associated cold upper air, moves east across the UK - creating steep lapse rates. So hopefully will be a classic April sunshine and showers day with some good cloudscapes in the clean Pm airmass, with hopefully enough CAPE developing in the stronger sunshine now for a few thunderstorms to pop up - perhaps Midlands best spot.

[Coast]

Was just having a poke through Sundays potential:

[knocker]

Sunday still showing a widespread potential for some convection, as an Atlantic trough, with associated cold upper air, moves east across the UK - creating steep lapse rates. So hopefully will be a classic April sunshine and showers day with some good cloudscapes in the clean Pm airmass, with hopefully enough CAPE developing in the stronger sunshine now for a few thunderstorms to pop up - perhaps Midlands best spot.

I see where you are coming from. This scenario has changed somewhat since I had a look yesterday.

[Nick F]

Bit clearer to see the potential on the N-W charts:

[Coast]

I'm still getting to grips with this new chart, I've read the bumpf but can someone give a laymans run down as this seems quite interesting and relevant:

http://www.virtuallab.bom.gov.au/meteofrance/cours/anglais/ac05/ac05001.htm

[knocker]

Bit clearer to see the potential on the N-W charts:

Thanks for that Nick. Hadn't got around to finding those charts. The GFS outlook supports this view although the instability could be considered marginal I suppose.

[Stuart]

I Just read our Forecast on met office site there say showers risk of thunder on Sunday

[Lewis]

Surprised people's missed tomorrows potential.

21-22C returns around the humber, east midlands and parts of EA with a couple hundred CAPE and a neutral to -1 lifted index, could spark a few home grown off especially North of the Wash.

Lewis

[Nick F]

Surprised people's missed tomorrows potential.

21-22C returns around the humber, east midlands and parts of EA with a couple hundred CAPE and a neutral to -1 lifted index, could spark a few home grown off especially North of the Wash.

There is some energy available in the atmopshere tomorrow, but it looks to be well capped by warm air advection aloft and at all levels. Unforunately when a few 100 j/kg CAPE are shown it doesn't always mean storms will develop!

Saturday afternoon across Ireland and Sunday more widely across the UK could see an opportunity for storms, as we see colder air advection aloft from the west steepening lapse rates and eroding the cap.

[Coast]

Surprised people's missed tomorrows potential.

Not really, its so low as not to be worthy of note, perhaps you are looking at something I've missed? Sunday is the next best chance and that will be over NI and NW Scotland I think:

[knocker]

Nick, I notice on the your lapse rate charts the 850mb and 500mb levels are used. Excuse my ignorance but is there a reason why these are preferred to the the 700mb and 500mb levels which I understand to be a more than useful expression of lapse rate for convective forecasting. I no doubt understand incorrectly.

[knocker]

Most thunderstorm activity this morning is centred over Greece. I had a look at the midnight sounding for Heraklion and it would support this scenario but I admit to be confused by a couple of the stability indices. An LI of 6 for example.

[staplehurst]

Surprised people's missed tomorrows potential.

21-22C returns around the humber, east midlands and parts of EA with a couple hundred CAPE and a neutral to -1 lifted index, could spark a few home grown off especially North of the Wash.

Lewis

Just to clarify, your 21-22C is for surface temperature as opposed to the official 2 metre readings. The highest in that case was 20C in north Norfolk and across the Fens.

[risk of sleet]

Showers now venturing inland in the most south/west parts of the rolfaroo. Will the instability deliver?

[Marcus_surfer]

certainly some very heavy activity off to the southwest at the moment. Temperature has gone from 11.0C to 12.1C and these showers have come straight from NW france looking at the radar. Isolated rumble of thunder possible?