Convective Weather Discussion Uk

[Stormyking]

You know what? Friday atm looks vaguely reminiscent to the 9th May 2001 - which saw storms develop from the near continent - as my account in the Thunderstorm guide mentions:

The afternoon and evening of May 9th 2001 was overcast, grey and cool in SE England with stratus lapping off the North Sea in a cool ENE airstream. However, to the South over France a warm and moist plume was steadily being advected Northwards. As the front of the warm air collided along a convergence line with the cool air that had been feeding in from the NE at the surface over the Dover Straits and SW North Sea, the warm moist air was forced to rise and rapidly built into towering cumulonimbus cells around Calais in the late evening. Further cells then rapidly multiplied NW across SE England around midnight with warm air continuing to be forced aloft by cooler air flowing in from the N Sea at the surface. These cells produce spectacular lightning displays and merged to form an MCS which practically engulfed the SE corner. As the storms cleared NW, instead of the air becoming fresher, the air turned more humid, and the following day saw a sticky 25C reached compared to the cool day previous. The funny thing was, the Met Office forecasters were rather caught out and left with red faces as they had predicted a small chance of some thundery showers for the South that evening. They didn't forsee a rapid explosion of severe thunderstorms and blamed it on cool air from the North Sea colliding with warm air off the continent.

Synoptic situation at 00z 10th May 2001:

Friday's fax chart for midday (t+72):

Probably won't pan out that way - despite the synoptic similarity, as any storms will be probably be home-grown on Friday

That would be pretty amazing if that did happen, but hey it isn't impossible for it to happen again , I just looked at chart Archive on 9th may 2001 compared to friday and I have to say as well that it looks almost similar just Almost.

[Sprites]

I remember those storms 9th May 2001,ive got video of the lightning that night, some very close CGs that broke up into beads, and a few strikes that had deafening thunder around 1second after the lightning!

Ive found that the drawback of a N.E. wind during May and early June, is that any storms arriving from the continent are shrouded behind low cloud from the North Sea, one night when storms were tracking over my area, i heard the thunder before seeing any lightning, due to low cloud.

Edited April 26, 2011 by Sprites

[conor123]

18z still looking very positive across the South, Friday Night in particular looks interesting as after a few hours of South Easterlies the colder air from the North Sea starts to move back down again while warm air continues advecting up from the continent, fingers crossed it moves this risk northwards as missed out on the storms here Friday & Saturday by a mere 10 miles both days!

[knocker]

The latest from the METO. I'll be glad when Friday is out of the way as I'm rapidly losing the will to live.

Outlook for Friday to Sunday:

Some sunshine, but cloudy at times and with a chilly northeasterly breeze. The wind will become stronger by Friday, and also with an increasing risk of heavy showers developing. One can perhaps see where they are coming from but two days is a long time in meteorology.

[Mesoscale]

Any body get woken by thunder?

apparently someone from the south of where i live got woken but thunder and rain at 6am???

Ignore that hes currently in Atlanta, GA haha!

Edited April 27, 2011 by Mesoscale

[Azores Hi]

You know what? Friday atm looks vaguely reminiscent to the 9th May 2001 - which saw storms develop from the near continent - as my account in the Thunderstorm guide mentions:

The afternoon and evening of May 9th 2001 was overcast, grey and cool in SE England with stratus lapping off the North Sea in a cool ENE airstream. However, to the South over France a warm and moist plume was steadily being advected Northwards. As the front of the warm air collided along a convergence line with the cool air that had been feeding in from the NE at the surface over the Dover Straits and SW North Sea, the warm moist air was forced to rise and rapidly built into towering cumulonimbus cells around Calais in the late evening. Further cells then rapidly multiplied NW across SE England around midnight with warm air continuing to be forced aloft by cooler air flowing in from the N Sea at the surface. These cells produce spectacular lightning displays and merged to form an MCS which practically engulfed the SE corner. As the storms cleared NW, instead of the air becoming fresher, the air turned more humid, and the following day saw a sticky 25C reached compared to the cool day previous. The funny thing was, the Met Office forecasters were rather caught out and left with red faces as they had predicted a small chance of some thundery showers for the South that evening. They didn't forsee a rapid explosion of severe thunderstorms and blamed it on cool air from the North Sea colliding with warm air off the continent.

Thanks very much Nick. I remember that storm well but I couldn't remember the date! I remember going out for a chinese meal in Tenterden that night, as we went in it was cool and cloudy, no hint of a storm at all but when we left it was pouring down. The rain was intense on the drive home and by the time I got back the lightning and thunder was constant and quite terrifying.

One of the most intense storms I can remember actually! Certainly in the top 3 or 4...

[Coast]

Still looks interesting...

CAPE looks limited

[Harry]

I think the up and coming weather is certainly quite exciting - if we're unfortunate not to get any direct hits, then I think we stand a very good chance at seeing hours of lightning out to the S and SE.

While I find it immensely frustrating when storms stick to the continent, I never the less do enjoy watching big Cb's creating their own disco on the horizon! I'm already trying to woo the other half into letting me creep down to the coast on Friday night/saturday...with little success thus far it has to be said lol

Just waiting for the 06z now, which for some reason TENDS to be less optimistic (ie scales down CAPE, LI and storm risk) than the 12z and 18z...I have absolutely no reason for this, it's just something I've noticed over the last few years.

EDIT - MetO page some what misleading - pressure charts show a fat trough slicing the SE and not moving much, for about 24 hours (Friday 12z into Saturday 12z) yet on the regional forecast, indicating showers/storms pretty much exclusively across the coastal areas...which is it? lol

I wonder how well the MetO will handle this potential convective outbreak nearer the time!!

EDIT - Reading the Model Output Discussion, you'd think we were in for weeks and weeks of cold, cloudy, poor weather. ECM however, after indicating a potential plume setup in the coming week or two, is indicating something worth keeping an eye on IMO in the coming couple of weeks. While subject to change and while not perfect for plume storms, is heading roughly in a good direction.

Edited April 27, 2011 by Harry

[SteveB]

Well our local BBC weather are going for showers on Friday & storms on Saturday.

Fingers very much crossed on this one.

[Methuselah]

I think the up and coming weather is certainly quite exciting - if we're unfortunate not to get any direct hits, then I think we stand a very good chance at seeing hours of lightning out to the S and SE.

While I find it immensely frustrating when storms stick to the continent, I never the less do enjoy watching big Cb's creating their own disco on the horizon! I'm already trying to woo the other half into letting me creep down to the coast on Friday night/saturday...with little success thus far it has to be said lol

Just waiting for the 06z now, which for some reason TENDS to be less optimistic (ie scales down CAPE, LI and storm risk) than the 12z and 18z...I have absolutely no reason for this, it's just something I've noticed over the last few years.

EDIT - MetO page some what misleading - pressure charts show a fat trough slicing the SE and not moving much, for about 24 hours (Friday 12z into Saturday 12z) yet on the regional forecast, indicating showers/storms pretty much exclusively across the coastal areas...which is it? lol

I wonder how well the MetO will handle this potential convective outbreak nearer the time!!

EDIT - Reading the Model Output Discussion, you'd think we were in for weeks and weeks of cold, cloudy, poor weather. ECM however, after indicating a potential plume setup in the coming week or two, is indicating something worth keeping an eye on IMO in the coming couple of weeks. While subject to change and while not perfect for plume storms, is heading roughly in a good direction.

I quite agree with you there, Harry. I think that some folks have gotten too used to temps in the 20s. It's only April afterall...

And, touch wood, some more good storms this weekend?

[Static Prevails]

No risk here, which for once, I think is good. I'm going to Alton Towers on Friday, and while riding Oblivion during a thunderstorm would be good fun, it would also probably be illegal...

Good luck down there though! I hope you get a nice display!

[Harry]

It is ONLY one run, but the 06z has shown a massive improvement.

The 00z was keen to clear and storm potential away from the south coast by Sunday...the 06z however indicates storm potential through until Wednesday.

Also, GFS falling in line with ECM and indicating a potential southerly, plume setup later into the first week of May.

No finer details available yet as we are still outside of a reliable time frame (even for the coming weekend IMO)...but the TREND at the moment IMO is very encouraging indeed

[NUT]

Plume setup's in early May are fantastic for us (May 2006 is a perfect example) As long as it's ok for the 13th to the 15th ie. no storms when I go down south then it can storm all it wants up to then

[Stuart]

i cant find any storm risk here at all

[SteveB]

The models are starting to move away from the cool cloudy weather into something much more interesting.

Hopefully a trend that will stick.

[todd1970]

Plume setup's in early May are fantastic for us (May 2006 is a perfect example) As long as it's ok for the 13th to the 15th ie. no storms when I go down south then it can storm all it wants up to then

Indeed..who could forget that one,one of the best displays of lightning ive ever seen in my life..heres hoping for a similar set up soon..surely 5 years without a decent storm we are due something ?

Edited April 27, 2011 by todd1970

[Coast]

I think the up and coming weather is certainly quite exciting - if we're unfortunate not to get any direct hits, then I think we stand a very good chance at seeing hours of lightning out to the S and SE.

I know people will think this is an SE bias - and really it's not!! But I am really pleased to see potential this early on in the year, even though it's a way away yet. But people may not understand the frustration of us SE dwellers who have to look barely 30/40 miles to the south to see action in France or Belgium that never gets to us.

I'm not counting any chickens, but a few distance flashes and rumbles over the weekend will be enough for me at this time of year, anything else is a bonus.

[Harry]

I know people will think this is an SE bias - and really it's not!! But I am really pleased to see potential this early on in the year, even though it's a way away yet. But people may not understand the frustration of us SE dwellers who have to look barely 30/40 miles to the south to see action in France or Belgium that never gets to us.

I'm not counting any chickens, but a few distance flashes and rumbles over the weekend will be enough for me at this time of year, anything else is a bonus.

Indeed, exceptionally frustrating!

MetO are backing away further from a potential thundery outbreak.

[Sprites]

Indeed, exceptionally frustrating!

MetO are backing away further from a potential thundery outbreak.

Low cloud from the north sea would make any night time storms hard to watch,it often happens during May, this looks to be a daytime convective set-up, any storms dying away at dusk...

[Andy Bown]

We're going to Cornwall this weekend so hopefully the thundery potential will exist there too!?

Saturday has been a thundery day so far this year with a storm on the afternoon of 26 March, nearby thunder on the early morning

of 2 April and nearby single cell storms last Saturday afternoon!

I remember those storms 9th May 2001,ive got video of the lightning that night, some very close CGs that broke up into beads

Hi Sprites, what do you mean by the CGs breaking up into beads? Thanks.

[Harry]

Low cloud from the north sea would make any night time storms hard to watch,it often happens during May, this looks to be a daytime convective set-up, any storms dying away at dusk...

Why do you think this is a daytime convective set-up?

The charts to me suggest that storms could potentially last well into the night, maybe even initiate during night hours.

We're going to Cornwall this weekend so hopefully the thundery potential will exist there too!?

Saturday has been a thundery day so far this year with a storm on the afternoon of 26 March, nearby thunder on the early morning

of 2 April and nearby single cell storms last Saturday afternoon!

Hi Sprites, what do you mean by the CGs breaking up into beads? Thanks.

This is an excellent example of CGs breaking up into beads (at the end of each stroke)

Edited April 27, 2011 by Harry

[Sprites]

We're going to Cornwall this weekend so hopefully the thundery potential will exist there too!?

Saturday has been a thundery day so far this year with a storm on the afternoon of 26 March, nearby thunder on the early morning

of 2 April and nearby single cell storms last Saturday afternoon!

Hi Sprites, what do you mean by the CGs breaking up into beads? Thanks.

Hi Andy, sometimes when a CG is less than a mile away it appears to break into dots as it fades away, "Bead lightning" maybe the lightning channel forms a type of plasma ,ive seen it a few times even in daytime storms, it shows up well on video if the C.G. is close

i cant view vids atm as im using phone lol

Edited April 27, 2011 by Sprites

[Andy Bown]

Thanks Harry and Sprite, haven't seen that myself - superb video Harry!!

[Lynxus]

This is an excellent example of CGs breaking up into beads (at the end of each stroke)

The "beads" you are referring to are just parts of the stream of plasma made by the electrical charge.

Every possible strike on earth will have the same kind of effect.

Looks cool but is simply just normal behaviour for any kind of electrical discharge.

[Harry]

The "beads" you are referring to are just parts of the stream of plasma made by the electrical charge.

Every possible strike on earth will have the same kind of effect.

Looks cool but is simply just normal behaviour for any kind of electrical discharge.

Interesting, I did not that every lightning strike beads afterwards.

Impressive when you see it though