Chris K

Looks like it is weakening in all honesty. I'm personally calling it quits shortly with sferic activity stopping just to the SW of here. Rather be woken up by something than stay up making myself tired and end up with bog standard rain.

Very true! If I get woken by up thunder tonight I will be more than happy to suffer a yawnfest at work tomorrow

Tell the storms to stop teasing me by dying down as it gets closer to Bristol...

Very nice...but only thing that worries me is the Met Office forecast it to weaken as it crosses the English Channel....here's hoping it doesn't!!

I think I jinxed it...

A couple more detected to your SE...really is not far and if the energy keeps its going you would be unlucky to not see something!

Difficult to tell myself but C/S counties somewhere between Bristol and London is a good shout I reckon - if it keeps going! Although Met office forecasts it to move towards Cornwall and W Country?

Strike detected near Cheddar, Somerset just now I wouldn't give up yet!

Yep strike shown up off the coast not far from Port Talbot. You can almost draw the line where activity is kicking off. I hope it continues as I have not seen lightning late evening into the night for aaaaages.

Some impressive cloudscapes earlier but its gone cloudy and cooled down a fair bit now with a strong breeze...not sure what to think really with regards to tonight and tomorrow for the Bristol area.

My hopes are pinned on some precipitation being forecast to move up from the SW later this evening/tonight...but at the moment I am a bit unsure what to make of it all to be honest. Great stuff going on in Wales.

http://www.blitzortung.org/Webpages/index.php?lang=en&page_0=12

Get some pictures if you can!

Yep i have been experiencing this to but was putting it down to dodgy GFS data. Seems to be happenning most runs now though.

If it helps - here is the fax chart from 7th May 2011 - Low pressure is situated more to the west than what is forecast next week, allowing more warm air to advect northwards from the continent with what looks like embedded troughs and on this chart a thundery low developing in the Bay of Biscay.

I really wouldn't look into specific charts or forecasts too much it will drive you mad. At this stage there is still uncertainty on just how thundery any activity will be. Any advanced alerts, warnings, lightning symbols etc are highlighting the risk. Nothing is certain until the day...its hard to hold back my excitement but I know we have been here before only for it all to get quashed on the day. Plenty of opportunity being forecasted...just need to get to the nowcasting part and hope we get a delivery of the electrical kind!

This actually reminds me a bit of 9th May 2008 - not sure if some of you remember but there was a stalling cold front waving/stalling across parts of western england that evening and it gave me about a 3 hour light show as it was bumping against the warm, unstable air coming up from the SE. I personally don't expect that next week, as the low pressure system and front is modelled to be a bit "fluid" in movement, whereas back then it was held back by a Scandy block and temperatures were a tad higher. However, certainly plenty to keep an eye on and hopefully it won't be quashed by cloud amounts...that is my main concern at the moment....although if it moves up from the continent during the evening this may not be such an issue.

Possibly, but to be honest I seem to find around 2 days before is the point when the gradual push east in the pressure pattern (and any associated fronts) begins for this type of set-up. I am not saying it will happen this time,but if I was to place a bet now...

It's interesting to see the consistency in each GFS run, but until there is similarity between ops and mean outputs, I will stay a bit cautious as to how this is going to pan out. It only takes small adjustments in the Atlantic & European pressure patterns for us to either end up being influenced more by the cooler air, or the warmer, humid air from the South. Lots of time for change, although unsettled seems to be the key theme at this time (be it mild or more warm). It is not uncommon for the models to produce outputs showing low pressure disturbances moving up from the South late Spring & Summer, only for them to either hardly form at all, or get pushed NE'wards across France/Belgium rather than more North towards the UK. The weather next week will also depend how far East the LP makes it as it also drops down towards the Bay of Biscay (If it does). Cloud amounts will also be a factor as well when it comes to thundery weather. Oddly enough people mention that GFS often models LP systems too far East but actually I find the opposite happens more often during the Late Spring & Summer period. So many times it would edge just that bit more East day by day for patterns like what GFS has shown this morning. I could be wrong, but that's my interpretation of this type of pattern from folllowing the models in recent years.

Yes quite an important point because the more tasty outputs are still 5-7 days away. If you have been following this thread for a while now, you realise that MOST of the time they will downgrade as we get closer to the day in question. Ideally, a more slack low pressure to our W/SW, that is enough to create instability and also draw up moist airmasses from the continent, is what we want to see. However we do not want it to move too close, or moving NE'wards too quickly at the time, to push any thundery weather into the North Sea and beyond. The interesting thing for me is that the trend for the trough to sink to our SW and towards the Bay of Biscay has shown up in GFS FI for a few days now, with it throwing up disturbances from the South towards us. ECM wants the trough closer to us, keeping the warmest air for the SE corner and continent. So for now, it is too uncertain to say what will happen until we start seeing more agreement on pressure patterns for next week. At least we have some exciting charts to twiddle our thumbs over and watch from behind the sofa...

Away from the short term briefly, I wonder if we could be seeing the start of a pattern taking place whereby the trough forecast to be to the W of the UK next week actually eventually brings us a thundery spell of weather? The chances of this could potentially increase if it starts to transfer towards the Bay of Biscay. There have been quite a few models runs the past few days suggesting this..but of course it will depend how things change with the trough positioning in the models after this weekend. Not to be taken seriously at the moment, but something to keep an eye on. Difficult enough to forecasts storms within 1-2 days never mind 1-2 weeks.

Fantastic guide. Very useful with lots of detail that was easy to understand. Thank you

Is this the latest one? Says this chart output was initialised on the 8th of May at the top and I am not sure how often these get updated?

It all depends how you interpret Gibby's post, but I agree with his words to be honest. The models have so far more repeatedly shown low pressure to gradually push the High pressure away after a few days, rather than have it sat in place for longer, be it FI or not. That to me is a strong trend at this time. This may well shift in favour of longer last high pressure in a day or two...who knows. I certainly do not think Gibby is calling anything at this stage - he is just explaining the likey outcome if it was to go that way.