Upcoming Convective / Storm Risk Discussion - w/c 12th May

[Convective]

For some reason I have a 32% storm chance between 12am and 1am tonight! Strange.. although the majority of ours storms strike in the night over here!

[Kain]

I'm sorry? Where did that just come from?

Read through some of your messages today, you will find the answer..

[Ben Sainsbury]

However unlikely it will be, the best place for storms into tonight should be around Nottingham, still a few sharp showers to the south which may give some hail!

[East_England_Stormchaser91]

Nothing here in Portsmouth today, infact it was a warm sunny day. Get me to Peterborough and East Anglia/Lincolnshire (thank god I am soon), its like Kuala Lumpur or Singapore compared to down here, the sea just kills everything off. Except Imports, which aren't half as good as what they'd be with the absence of the English Channel. 

[nitro_deluxe]

Mean looking skies this evening but not quite a brutal thunderstorm..quite typically half a dozen or so flashes and bangs is better than nothing at all?

All way after 8pm too, much to my surprise.

June shall bring more of the goods watch this space

[Convective]

Hmm, apparently 2 sferics just off the coast of here now? Not sure if they're genuine!?

 

EDIT: Looks like this entire system over the UK has a bit more energy in it before it goes!

Edited May 16, 2013 by Convective

[nitro_deluxe]

Already looking forward to the next after today's starter...here's to the main course! Leave the pud till the Autumn..

[Convective]

Some torrential showers through the south west corner today! Flash flooding likely to be a problem..

PLEASE NOTE that the red highlighted area has been put into effect under low confidence and is there mainly for the risk of severe localised flooding rather than the risk of potentially damaging storms. There are limited conditions favourable of strong thunderstorms however note that any storms that do initiate over the southwest are likely to be pulse type although some can be expected to continue for a few hours and are likely to contain a mixture of hail and frequent lightning.

Edited May 16, 2013 by Convective

[Tim B]

Was some loud booms around 7 PM here though it did not amount to much, I think it was in the dissipation phase by then though I did see some very nice CB formations on the train home around 5 ish.

[Arnie Pie]

Cell which snook into Brum last night(7.45ish) from the SEAs viewed from Frankley Beeches over Northfield

Edited May 17, 2013 by Arnie Pie

[Coast]

Morning all!

 

​Great to see some got a rumble and flash yesterday evening and that the info available to us was fairly accurate re: timing and area.

 

So what have we got today?

 

ESTOFEX have an area broadly the same as yesterday:

 

Storm Forecast

Valid: Fri 17 May 2013 06:00 to Sat 18 May 2013 06:00 UTC

Issued: Thu 16 May 2013 22:12

Forecaster: PISTOTNIK

 

SYNOPSIS

 

The Western European long-wave trough has finally cut off into a big upper-level low centered over the Bay of Biscay and Northern Spain. The main trough axis gets an increasing negative tilt, while it accelerates from Sardegna and Tunisia at the beginning of the forecast period northeastward across Italy and into the Balkan States.

 

The second main player on the weather maps is a large and stationary anticyclone over Northwestern Russia and Finland. Between these two steering centers, the flow has turned Southeasterly and advects warm and partly humid air, allowing an active convection day over much of the continent.

 

Meanwhile, cool maritime air continues to settle across Western Europe and pushes further into the Iberian Peninsula and the Western Mediterranean region. However, also these regions will see some convection, supported by diurnal heating and further passing vorticity lobes.

 

UKASF have:

 

Slight

 

Forecaster: Chris

Last Updated: 2013-05-16 18:50:00

Valid: 2013-05-17 00:00:00 - 2013-05-17 23:59:00

 

Areas Affected:

 

SW England and Wales, much of Ireland

Synopsis:

 

A broad area of low pressure will be located to the south and east of Britain with a weak surface trough situated through SW Britain and Ireland during the middle part of the day.

Discussion:

 

Scattered showers will develop in response to daytime heating across the slight area. Very little shear is forecast so storms will be of the pulse variety, but the heaviest showers may produce some isolated lightning with CAPE values of around 200j/kg in SW Britain. A pocket of slightly higher CAPE is forecast over Ireland, but also more cloud-cover which could inhibit potential somewhat. Either way, with limited instability and shear, hail and strong wind gusts are unlikely with just a few sferics being the main result.

 

Simple format GFS overview is inclined more to the SW coastal strip:

 

 

If it's right, expect timing for the end of the afternoon again

 

Aviation weather:

 

 

CAPE:

 

 

 

SBCAPE highlights nicely the areas under consideration  those being Cornwall, Devon maybe Dorset and Somerset and of course Ireland:

 

 

 

Tropoause chart also gives us a hint:

 

 

and LCL difference:

 

 

Steeper lapse rates out in the BoB and Channel approaches:

 

 

and MCS propagation areas right up to the Bristol Channel:

 

 

Not a huge confidence in today, but indicators are there and you can see the areas that might get some activity towards the end of the afternoon.

Edited May 17, 2013 by Coast

[BrickFielder]

Yes late afternoon in the south west and perhaps Wales. Mid level lapse rates not as good as yesterday and steeper rates do not come in until late afternoon.

 

Low level convergence zones are likely to be a focus.

 

Interesting change of wind direction through the mid levels.

Some diagreement between models on that though and lower level winds are not high enough to start thinking supercells.

 

Forecast SkewT's show some instability but tops being slightly limited.

 

 

Overall a risk of some storms in the south west late afternoon which are likely to be steered towards Wales. Possibility of some weak convergence zone type funnels, but main risk is localized flooding and hail.

[Liam Ellis]

"Overall a risk of some storms in the south west late afternoon which are likely to be steered towards Wales. Possibility of some weak convergence zone type funnels, but main risk is localized flooding and hail.

 

 

I like the sound of 'steered towards Wales'. Was slightly disappointed yesterday, nothing really came out from those showers for Cardiff. A bit hazy this morning though.  Hopefully today will be a better day! 

[Andy Bown]

This morning brought the first thundery looking morning of the year with patches of Altocumulus and some AltCas drifting NNW which I think were the remnants of storms from France yesterday. The only odd thing was to see such a sky with the temperature at 3c!

Convection is getting going now with clouds moving SSE-NNW on the SSE breeze and there is plenty of warm sunshine too.

[nitro_deluxe]

Couldn't have described it better myself Andy - that morning after the storms look to the skies.

So the emphasis shifts further SW today. Could be a few surprises for some later, isolated pretty active little storms quite possible with large rain spot totals and in places some hail.

Just need temps to rise accordingly for the real humdingers to arrive (waiting game goes on)

[Evening thunder]

I bet there will be a thunderstorm or interesting convective weather at home in Devon today, seeing as I'm not there lol. Nothing of much interest here at uni yet this spring so maybe home will end up being more interesting than here for convective weather too while I've been here, as well as most other types of weather at other times of year lol.

 

Edit: and there we go one of the heaviest cells developed so far now with a sefric a few miles away from my house and heading towards it.. quelle surprise

Edited May 17, 2013 by Stormmad26

[Coast]

Seems quite benign on SatRep really?

 

[Paul]

Few potent cells and storms starting to kick off now in SW England and Northern Ireland

 

[andymusic]

Few potent cells and storms starting to kick off now in SW England and Northern Ireland

 

storms.png

nasty looking cell over Swansea too

[Bobby]

An intense looking storm over Gower currently with plenty of lightning.

A few strikes over SW England too.

[Coast]

Few potent cells and storms starting to kick off now in SW England and Northern Ireland

 

Looks like it's going to forecast, but kicking off a little earlier today. I hope all of you in the area that missed out yesterday get something today and for the rest of us, that the season continues with a few surprises!

[Cheshire Freeze]

Looks like it's going to forecast, but kicking off a little earlier today. I hope all of you in the area that missed out yesterday get something today and for the rest of us, that the season continues with a few surprises!

 

Well missed out yesterday, the time before that, the time before that and oh the time before that too. Doesn't look like that's going to change today either!

 

As soon as I get one I'll stop moaning.....promise!

Edited May 17, 2013 by CreweCold

[Convective]

So far my forecast isn't holding up too badly. Think there could be some vicious activity later this afternoon and into the evening down the southwest and parts of Ireland indicated in my forecast from earlier on.

[A.J]

Thunderstorm developing over Exeter now....quite lively down there....I'm on the northern fringe of any anticpated storm activity, probably a tad too far north, but I'll keep my fingers crossed as I'm not chasing today

[Cheshire Freeze]

So far my forecast isn't holding up too badly. Think there could be some vicious activity later this afternoon and into the evening down the southwest and parts of Ireland indicated in my forecast from earlier on.

 

There'll be some vicious activity here soon if I don't get a storm; my laptop will be going through the window