Supacell

There seems to still be a great deal of uncertainty with regards to where the heaviest rain will be and where the best of any thunderstorms will be over the next couple of days. I think it would be fair to say that the south coast and just inland from there to the M4 looks best overnight tonight but where the storms actually are is anyone's guess. It is normal in these scenarios though. It really will be a case of radar watching and then tracking storms as they come into the south coast. The first batch of storms should then push north into the Midlands but at this point I have seen everything from them tracking NW to affect only the SW Midlands and Wales to NNW and affecting all of the Midlands and up into N England. On tracking north then I expect thunderstorms will tend to lose there intensity tomorrow. If we can get any sunshine breaking through behind this band then it will allow temperatures to shoot up as the air following this warm front is very warm and humid air. If the sunshine breaks through then I can see potentially some big storms breaking out and pushing NW. The next interest comes from the possibility of more storms coming out of France and Benelux towards the SE late tomorrow - and this is the area that interests me most from an IMBY point of view. Unfortunately this is 24 hours away or more and so the uncertainty here is quite high.

The latest GFS shows thunderstorms touching the south coast on Wednesday night and then erupting northwards to cover everywhere from Yorkshire southwards by Thursday night. Surface based CAPE develops to the value of around 1000 j/kg briefly to the south and west of the Midlands but elsewhere it is not very impressive. However, MLCAPE I would imagine is widespread. Friday a further pulse of thunderstorms look to affect eastern England, especially East Anglia with rain in the west. The precipitation charts are a mess but also awash with torrential downpours. The storm risk does not really get north of Yorkshire with the favoured spots being further south and through the Midlands on Weds night/Thurs and then eastern England on Thurs night/Fri. The latest NMM shows thunderstorms moving into the entire south coast Wednesday night and moving north on Thursday, much like the GFS. The SW will lose the storms during Thursday after a thundery night then places like the NE will get them on Friday. There is a huge amount of rainfall potential both from thunderstorms pushing north and then from a band of particularly heavy rain pushing east on Friday and sweeping away the thunder risk with it. It is a messy picture but current charts would I think favour widespread torrential downpours and mostly elevated thunderstorms both by day and by night. Of more concern though is the rain with torrential downpours likely to be off and on for 24-48 hours in parts and if some of these are dropping in the region of 50mm plus per hour you can imagine the disruption that could come from this.

As has been said the charts I posted yesterday were for MLCAPE. Storms overnight Weds into Thurs do look elevated with a fair amount of lightning and copious rainfall for some. Could be some gusty winds around these storms too.

I wouldn't want to swap either. Over the course of an average summer I would say France gets far more storms than the UK and better ones at that. Of course on occasion the UK does do better but it is rare. I remember you were in the UK on the 1st July which has been the best day for storms this year so far in the UK, at least for me and certainly in Yorkshire (if you can call supercells with golf ball hail over your house "best").

Indeed. NMM is showing the main event with regards to lightning being Wednesday night into Thursday for the southern half of the UK but then the main event for rain on Thursday/Friday. Some large rainfall totals if that came off and certainly the risk of flooding. MLCAPE for Wednesday evening into early hours of Thursday Precipitation for mid afternoon Thursday. Still some thunder likely in it by this point but less though than Wednesday night on the NMM latest run. Precipitation rate shows 70mm per hour. This rain moves SE to NW and lasts a while so as Nick says easily 2" plus. Caveat being it is all a distance away though in terms of timescales.

A decent amount of lightning running across Yorkshire/N England currently. Possibility of some sparks further south along that narrow line of showers, although north looks best.

After what has been a fairly quiet period on the storm front for most (i am aware there have been some storms around) it looks like we could see a few opportunities for storm fun next week. The main threat is midweek on with the models starting to agree now on some thundery weather affecting the southern part of the UK. There is still some uncertainty on how far north the risk goes and also how far west. In the nearer time frame there is the possibility on Sun night and Monday of seeing some thundery activity developing and moving SW to NE along a southeastward moving cold front - which is the dividing line between the hot, humid air to the south and the cooler, fresher air to the north. It is this front that will eventually turn into a warm front and move back north again from midweek drawing up the plume from the continent. Although the cold front is getting squeezed out by high pressure it does look to reinvigorate somewhat on Monday. Where is affected will be down to where the cold front is situated, this still uncertain too with some models placing it over N England, but others across the S Midlands and anywhere in between. Although CAPE is rather meager there is 200-300j/kg with a LI of -2 on NMM. Considering 60 knots of deep layer shear and a humid air-mass in place - GFS showing 22-25c with dew points of around 16c - it is one to watch I feel.

A few strikes with those showers moving across Cheshire, they may just skim me to the north.

Not a big convective day ahead but there is some interest at least for my area for around tea time into the early evening. I have my camera ready.

There is a line of wind convergence across N England all the way from the Lancashire coast to the Lincolnshire coast and here there could be some convergence zone funnel clouds. There is also likely to be some heavy showers focused around this line too. It can already be seen in evidence, currently more developed on the eastern side. However, I think any thunder risk is unlikely today. There may be a better chance of some thundery showers tomorrow late afternoon/evening across N England but even this is looking like a straw clutch.

I think you are a day late mate, it was the early hours of the 23rd two years ago :-)

The best of the thundery weather associated with this low looks to be across the north of France and in the southern Channel. However the 12z GFS does bring the risk of some thunderstorms into the far SW of Cornwall early tomorrow and then Kent by late afternoon/evening. If the low pressure system moves slightly north than this then it would bring a risk across more of the south. However, for most it looks like dynamic rainfall. This can be seen clearly on the two charts below for tomorrow evening - left is precipitation both dynamic and convective, right is just convective: Storm risk for the SE I would imagine a 100 mile shift north would bring the risk 100 miles north, but a 10 mile shift south would remove the risk for the UK entirely. The NMM has a very similar scenario although also brings more of southern and eastern England into the mix too by late evening. This is MLCAPE, showing the risk of some elevated instability. My current take on things is for there to be some thunderstorm activity in the Channel which will certainly affect the Channel Islands. There may be some thunder across areas such as Lands End and the Isles of Scilly early on and then a higher risk across areas to the SE of London later on. The risk of severe thunderstorms is unlikely as most would be elevated but outside of just convective severe weather there is a broad risk of heavy rain and strong winds which could (likely) to cause problem across the entire southern portion of England, especially the SE.

Just got back from Slovenia earlier in the month, a beautiful country. If you like scenery head for Lake Bled. It also records one of the highest frequency of thunderstorms of any country in Europe with on average over 25% of the days in summer seeing a thunderstorm. I went for 4 days and saw 2 thunderstorms

At this time of the afternoon, exactly one year ago, I was chasing a powerful rotating storm out of Coalville/Ashby area :-)

I think the risk is within the next couple of hours, after this any marginal instability moves off into the North Sea and most of the uk enjoys a pleasant, sunny afternoon with just a few light showers in the north.

Latest charts would say not with a NW flow in place by the end of the coming week bringing showers and cooler temperatures. There may be some thundery showers but it would be the polar maritime kind as opposed to the plume kind. Still a long way off though so things may become more favorable again.

This is probably because it is very rarely just one strike, there is often multiple strokes within a strike. Sometimes you can visibly see a bolt pulsing a number of times and other times it can appear like just one strike. I have filmed a lot of lightning over the last several years and a lot of them consist of multiple strokes that can only be seen when I slow the video down. The same would likely be true for lightning within the cloud (sheet lightning), possibly even more so as the flickering flash may involve several strokes of lightning transcending from one part of the cloud to another - sometimes visible as crawler lightning.

This is exactly the sound I heard before a storm on the evening of 22nd July 2013! I always wondered what it was, almost sounded like constant distant thunder but it was definitely this. Thanks for sharing

Nothing here last night, although we have some steady rain falling now from the cold front pushing through. For those that did get the storms overnight it looks from the videos, photos and eye witness reports to be quite similar to the 1st July across the NW with the constant flashing of IC bolts in the cloud being seen from a distance away. I witnessed this on that day and it was first time I had seen it in the UK, it has now happened twice in the space of 3 weeks. Not bad going at all!

Some intense precipitation on the V6 radar just to the NW of London, although not much in the way of sferics (at least not in comparison to other events earlier this month). It is the best storm in the UK currently though.

Met Office going with some cells breaking out further west from the current developing storm trail, maybe clipping into the Nottinghamshire/Leicestershire part of the East Midlands overnight. It does look like I am too far west though even for this. It would appear from reports elsewhere that some of these storms are not elevated and so you could be correct here.

I have put together a map with the rough current predictions from the main models. You can probably try and muster from this areas most at risk, although it could still go wrong! Black - General thunderstorm area from NMM/WRF Blue - More intense thunderstorms from NMM/WRF Orange - Risk zone from GFS Yellow - Risk zone from Euro4 Red - Risk zone from Met Office

East Midlands Airport TAF has thunderstorms from 22z to 04z prob 30%

Derby looks on the cusp of the action on most models but some have all the action east of here. It appears I would best to head east if I want a higher chance. However, I have seen a number of storms elsewhere and would quite like to be able to see one without having to drive. A repeat of the 4th July would be very nice.

Estofex do not normally release a forecast until early am.