Storm & Convective Discussion - 01/06/15 onwards

[DAVID SNOW]

Fantastic shots! Thank you

[stainesbloke]

Fantastic post Generalelectrix!! The 'swirl' pattern in the swathe of downed trees is very noticeable. Those pics could easily be from the USA, that anvil looks positively evil! If only we could import some storms like that....

[Harry]

MetO seem to edging away from heatwave Friday, suggesting temps of 21-22C in London with "thundery showers" in the SE.

Let's hope for a shift in models tomorrow and Wednesday to something a bit better than that!

Edited June 1, 2015 by Harry

[Captain Shortwave]

MetO seem to edging away from heatwave Friday, suggesting temps of 21-22C in London with "thundery showers" in the SE.

Let's hope for a shift in models tomorrow and Wednesday to something a bit better than that!

Rather ballsy to go with their raw data considering it has next to no support from the other models and ensemble suites. Something is going to give though.

[Daniel*]

MetO seem to edging away from heatwave Friday, suggesting temps of 21-22C in London with "thundery showers" in the SE.

Let's hope for a shift in models tomorrow and Wednesday to something a bit better than that!

On local (ITV) top temp of 26C on Friday with the âš¡ï¸âš¡ï¸âš¡ï¸ symbol much more realistic. I feel the heat is more likely to get upgraded than downgraded after the initial dilution.

[Harry]

GFS 18z about to unveil its latest punt...this was yesterday by far the most miserable of the runs yesterday so will be interesting to see what it says.

[Captain Shortwave]

The pub run is okay, a little east compared to the 12z, but the 12z was the furthest west of the operationals and this run takes it more in line with the ECM/GEM outputs.

 

The FAX chart for day 4 sums up the metoffice thoughts, similar in the surface pattern to the raw output with decayed fronts over the south providing a fair bit of cloud which suppresses the temperatures.

Edited June 1, 2015 by Captain shortwave

[Utahraptor]

18z not looking as nice as the runs before it, hopefully it will improve tomorrow :/

[Staffordshire]

Yeah looks like escaping from central England if this trend continues, East anglia, East mids, London and the SE still good

[Harry]

It does my nut in these charts lol - don't know why I'm doing it to myself.

18z shifts it 50 miles or so further East to 12z, but still keeps most of England and Wales in the bullseye. It hangs around for about 12-18 hours before shunting off so is an extremely narrow window of opportunity.

Let's review again this time tomorrow.

[East_England_Stormchaser91]

A little bit far out and more runs needed, but at the moment I think the main area at risk will be in a line from the IOW up to Leicestershire/Lincolnshire Eastwards. This is how it is looking to be certainly at the moment. Would still not surprise me at all though for all of this to dive 100-200 miles East and leave us with little more than nothing and to see Belgium and the Netherlands take the brunt of this, as has been experienced so many times before. Can only wish for a triumph of hope at the minute.

[sunnijim]

The pub run is okay, a little east compared to the 12z, but the 12z was the furthest west of the operationals and this run takes it more in line with the ECM/GEM outputs.

 

The FAX chart for day 4 sums up the metoffice thoughts, similar in the surface pattern to the raw output with decayed fronts over the south providing a fair bit of cloud which suppresses the temperatures.

dreary.gif

As with the winter snow 'eye candy' charts available to joe public,its important to remember ukmo have other models we don't see,so if the 'family fax' is stearing away from storm 'eye candy' of certain public models there is sure to be a very good reason.

[Chris K]

GFS always following - never leading. ECM is still quicker than the 18z. My thinking is that it's either an east based risk, or no risk at all. But it would seem a widespread risk is rather unlikely.

We've been here many times before and as much as I want to believe it won't, the likelihood is you're once again correct and there will be a further push east. The SE could do well, but for someone like myself in the West, frustratingly it could be a no show. As you've also repeatedly said, UK meto model isn't playing game and the GFS op moves towards the Euros again. Oh it likes to tease.

I'd much rather see a stalling low out to our west spiralling fronts against a blocking high to our east. Once again though it looks to push on through thanks to the overarching pattern.

Let's see what the models bring us tomorrow...

Edited June 1, 2015 by Chris K

[Mapantz]

Ever so slowly creeping Eastwards, but not game over by any means.

[Ben Sainsbury]

Ever so slowly creeping Eastwards, but not game over by any means.

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It still does suggest a few thunderstorms, across more Central areas too! If only the models could agree on the current GFS 18z run, then there could well be potential. Being that GFS and ECM now both agree, hopefully we can have consistent runs.

Edited June 1, 2015 by Ben Sainsbury

[Supacell]

Still some chopping and changing with the predicted plume on the overnight runs. A clear eastward shift on GFS and NMM on the 00z run but still a good portion of the S and E of England in the plume zone. However, with 3 days left to go until storms are expected the eastward shift concerns me. Still all to play for regarding Friday but it could still end up one of those near continent shows. 

 

The BBC have not been mentioning anything for Friday this morning.

[Harry]

00z is depressing - alas, GFS falling in line with euro models.

Now it's knife edge as to whether anywhere sees anything of interest - optimism plummeting I have to say.

[Harry]

Numerous times every year we have this predicament - how quickly will the Atlantic push in.

It is not inevitable the Atlantic progression won't slow - I can recall occasions where 12+ hours inaccuracy even a short range has taken place - obviously such an error can work for or against us.

[Harry]

Regional forecast on MetO better than yesterday though...

 

Dry and relatively warm with variable cloud and sunshine Thursday. Perhaps cloudier, but warmer Friday with a chance of thunderstorms later. Then, dry with sunny spells for much of Saturday.

[stainesbloke]

Quite like the fax for Friday, still a good chance for heat and storms across much of S and E England with the cold front out west for much of the day. Would prefer the modelled trough to be further west...might well happen in future runs! All on a knife edge, as ever lol....

Edited June 2, 2015 by stainesbloke

[BrickFielder]

  Tricky scenario for Friday with lots of potential to change. Typically models tend to move convective potential eastwards two to three days out and then down grade a day before. On the day the models will often slightly upgrade potential and move it back westward a touch. Relying on historical performance bearing mind models are constantly being upgraded is always risky.

  A developing low system pass northwards just to the west of Ireland with a trailing cold front probably over Ireland. This puts the UK in the warm sector with a long pull of warm air coming from around Spain. Models suggest a trough develops over northern France and stretches northwards during Friday while moving slowly eastwards.  The question will be how long the air feed from Spain will be in place and will it really have time to feed heat northwards. There is also a boundary between the warm feed from Spain and the cooler but moister maritime air from the Atlantic.

Even at low level you can see a potential marked boundary between the hot feed of air and the maritime air potentially leading to low level wind convergence zones over the UK.

Over Laying the 925hpa height winds would give areas of marked low level vorticity.

With the jet stream powering overhead slightly out to the west there is potential for mid level vorticity as well.

Based on this I would not be surprised to see some excitement based on lightning wizard tornado and super cell forecasting charts tomorrow.

 

These charts might need to be taken with a little pinch of salt for the UK on Friday. This is a sort of Spanish Plume scenario which tends to mean that storms are elevated and not surfaced based (Tornadoes not possible). The plume at this point has not really got going for the UK, 850hpa temperatures are elevated, but mid level steep lapse rates are a little late arriving and surface temperatures may not get the chance to rise into the high twenties. A GFS forecast skewT for London shows the problem with unstable air above 800hpa but a marked CAP against surface based convection.

 

I think it might be better to start thinking about two separate areas of convective potential over the UK for Friday. To the south east initially there is a risk of elevated storms producing Lightning but not much in the way of rain. The second area of interest is the boundary between the plume and maritime air which moves north and eastwards across the UK. The risk here is that an MCS develops to the south of the UK which keeps temperatures low and you just get lots of rain.

 

Some more charts from Friday.

 

Some rainfall predictions which are bound to be wrong as well  (This is only one models output and none are in agreement).

 

Some things perhaps to watch out for are elevated storms becoming surface based in the east. Lead storms moving north or storms in a convective line break. It is of course way to early for detail and the modelling is bound to change over the next two days. My hunch would be that the timing is not quite right (instability moves in over night, french storm outflow from previous day, surface temperatures not high enough) for significant convective potential based on current modelling. Key places for me at the moment might be London and somewhere like Hull, but I expect to change my mind over the next day or so. There are however some potential ingredients for a severe storm to develop. More perhaps as we get closer to Friday.

 

Edited June 2, 2015 by BrickFielder

[NO LONGER POSTING]

Just starting to come into range and very good I must say..

 

 

 

 

 

Edited June 2, 2015 by Surrey

[Mapantz]

Don't forget Surrey, those are 8 hours old now, we're on the 06Z.

The 00Z was watered down significantly, the 06Z the same, and moving through quite rapidly.

06Z

00Z

Personally, it's getting to that stage where you can say "a few thundery showers in the south east"

Edited June 2, 2015 by Mapantz

[Convective]

What completely depressing charts today. Gone from good to bad to good to bad once again.. Could we perhaps get one last shift to good before Friday please?

[Supacell]

So will it be a long drive to Kent, a ferry to Belgium or a beer and my laptop watching the webcams in Germany on Friday night?

Trying to not feel too down even though I did make the mistake of getting excited about this.

Edited June 2, 2015 by Supacell