Supacell

Potentially good thunderstorm set up for tonight and more especially tomorrow. It does require a few parameters to fall favorably though for the best of it to be realised. Tonight it looks like an increase in CAPE close to the south coast and just inland from here from around 00z onwards. This could promote an increase in thundery activity during the early hours within the showers that will tend to run into the south as a developing area of low pressure moves up from the south-west with an occluded front pushing north. Wind shear is weak and so organised thunderstorms are unlikely but I would not be surprised to hear some reports of thunder even before dawn tomorrow. It is into tomorrow that my interest increases as some decent SBCAPE develops and expands from the south into a good proportion of England and Wales south of N England behind this occluded front. Euro4 seems to indicate scattered convective cells developing within this post frontal zone and moving slowly north through the morning invigorating along a line moving northwards through the Midlands in the afternoon. Currently the best of the instability remains ahead of any deep layer shear though and this would reduce the possibility of anything organised but low ELT's, CAPE in the region of 300-500j/kg and decent lapse rates may allow for some electrically active pulse type storms running north with this line. The line is marked by an area of wind convergence and this could promote the chance of storms organising along this line. There is a lot of moisture available within a humid TM airmass and this could mean some torrential downpours with a lot of rain falling in a short space of time. It may also work to limit convective potential though as extensive cloud cover may scupper chances during the day. Showery rain moving into the south coast this evening has the potential to contain some convective and weakly thundery cells during the early hours. This moves northwards through to northern England by midday/early pm tomorrow as a weakening feature. Behind this a few heavy showers could break out along a convergence zone and push northward through CS England and into the Midlands through the day to sit across N England by evening (WRF moves this through a little slower and thus it does not get as far north as on GFS). Should there be any surface heating this is likely to promote thunderstorms to develop as it pushes northwards and these could focus across this convergence zone. Extensive cloud cover and thus lack of surface heating could prevent cloud tops attaining the required height for storms. Any thunderstorms that do develop could be quite electrically active at times but will likely be of the pulse type variety. Should surface heating occur and shear overlap instability and convergence then this could allow for more organised and possibly severe storms, although this looks unlikely looking at the current suite of charts I have seen.

It is indicating the area of low pressure which is old tropical storm Henri.

It is a fair distance away but for a few runs of the GFS and NMM there has been a risk of some storms showing on Saturday. CAPE looks to develop across western and central areas by midday and moves north-east near to the centre of an area of low pressure. There will be ample moisture and also some deep layer shear in place. I am also interested in a triple point which is showing up on the met office pressure charts for the same time and same area. It is one to watch for now as if these parameters do come together we could have a decent convective situation.

There is a thunderstorm near to Harwich/Felixstowe but not much anywhere else. You are right though, no thunderfest expected today. I do hope to see another southerly plume during September/October.

If you look closely at that last funnel picture it looks like there is some water being brought up underneath it. Could that be a waterspout caught there? Actually it is even clearer on picture 2. The thinner funnel is a waterspout as it is clearly sucking up water. Great captures.

Heading my way I think, I just hope it doesn't disintegrate like the last one.

Other than the cell in South Cumbria the showers are pulsing up and back down very quickly. This is a storm chasers nightmare and over the years I have learnt I am better to just stay in one place and hope for the best than try and chase pulse storms. I am thinking wind convergence is probably playing a part across Cumbria as that cell is still going and now spreading into NW Lancashire.

Strikes to the west of Derby, if only they were moving W to E. As it is that shower will pass to my west. Plenty more showers to the north-west though and some are producing sferics.

I have my camcorder ready for any storms that may develop this afternoon and evening over my area. It is a low risk but Derby does look to be in the risk area. The lapse rates across the northern half of the country look quite impressive but CAPE is weak. Unfortunately the best deep layer shear is across the south and does not overlap the best of the CAPE and lapse rates, if there had been some crossover then stronger storms may have occurred, although the area across the North Midlands could just about see advantages of both. A number of troughs moving south in the northerly flow will likely enhance the showers. What today will be is a day of sunshine and crisp convection with some beefy showers. To my eye there is the risk of some weak thunderstorms and this looks especially true for the late afternoon and evening period across Northern England and the North Midlands.

Weather warning issued by the Met Office for N Wales, NW England, N England and the N Midlands for this evening, tonight and tomorrow am. Issued at: 1638 on Mon 31 Aug 2015 Valid from: 2000 on Mon 31 Aug 2015 Valid to: 1000 on Tue 1 Sep 2015 Showers affecting parts of northern England and north Wales through Monday afternoon may merge together on Monday evening to give a period of more prolonged and at times very heavy rainfall. This will then sink southeastwards through parts of the Midlands and East Anglia overnight and into Tuesday morning. There is a great deal of uncertainty in these developments with many areas only seeing small amounts of rainfall. Where the heaviest rain falls some localised flooding is possible and the public should be aware of the potential for disruption. http://www.metoffice.gov.uk/public/weather/warnings/ I wonder if there could be the odd thunderstorm amongst this? There is some weak CAPE, decent lapse rates and some deep layer shear. Tomorrow afternoon these parameters all look to get better briefly but this is after this warning expires. Something to watch at least.

Completely agree with this. I don't really feel too disheartened as I was never planning to travel as far as Kent to see a storm. I never expected anything and so don't feel I missed out. Indeed I have seen some great storms this year, although there have not been many but those that there have been have virtually all been good. September and October can produce some very good thunderstorms and I have seen some great storms over the years in September/October. By October the risk is starting to become restricted more to coastal areas but this is not to say they can't occur inland. It still looks quiet for the next 2 weeks though, but the models can and will change.

Haha. I was with my kids in Great Yarmouth this past week including the very rainy Wednesday whereby the rain stalled across eastern parts and especially the North Sea. I told them that all this rain would probably cause flooding out to sea if it is there for too long! I am rather jealous, it looks pretty thundery down on that SE tip. This looks like the last decent thundery spell for a while as it is set to turn quieter into September (this appears to be the case most years). Chance for us Northerners/Midlanders of a few rumbles later today and more especially tomorrow in a polar maritime sunshine and showers set up but not the real thunderstorms like those in the SE today.

If I was living in that SE corner I would be getting quite excited now. It looks like a fun night could be on the cards. Interesting that this storm risk could be a little more widespread than first thought (still subject to further changes). I would expect anywhere from the capital southeast to be in with a risk of some impressive storms. For here in the Midlands it looks like just plain rain, although it is heavy rain with some large rainfall totals being shown on some models during the next 24 hours. Euro4 shows rainfall totals across Derby touching on 2 inches which is not really what you want on a Bank holiday. Higher totals are shown across Kent which may give rise to localised flooding.

Over the last several years I have found July to be the best month for thunderstorms. Really it depends where you live though. This year has not seen many convective episodes but those I have seen have been impressive (with the exception of those failed plumes which never materialised). It is still 2 months away from the end of the storm season though, so hopefully plenty more to come.

I am not sure it is edging this way. If it is then it would appear that it is dying as it does whilst new storms break out over the areas that have just had them. Unfortunately I think it is going to be a very wet and thundery evening along that line with little movement west. I hope to be wrong, would like to see another storm.

A line of thunderstorms developing in a line through Lincolnshire, especially around Grantham. They do not appear to be moving anywhere. It looks like a convergence zone setting up.

Finally finished editing and this is a video I have put together of the storm which I chased towards the village of Woore on the border of Shropshire and Cheshire during the evening. I was actually just to the west of the village.

Further north has been able to take advantage of the warmer, humid airmass ahead of the front for longer. High temperatures and the incoming cold front helping the air to rise and form thunderstorms. CAPE values always looked better in the NW today.

Looking like N England, especially NW is the place to be again today. It has not been a bad couple of days for storm lovers up there. Yorkshire has done very well too. It is the turn of the south over the next couple of days from looking at forecasts and charts.

Cold front moving NE is already reinvigorating in response to surface heating ahead of the front developing some weak CAPE and wind convergence along it. Having said that the dewpoints and temperatures are lower to the NE of the front than they were yesterday. It still feels warm and humid here but not the stifling heat of yesterday. Of more interest is the deep layer shear and helicity which looks to be highest earlier in the day before weakening a little as the front heads east (1st chart). The presence of these parameters also brings a low risk of a tornado (2nd chart). You can already see on the radar the front moving NE whilst the pulses of rain move SE to NW along it. Most parts though in the path of the front have a chance of seeing some flashes and hearing some rumbles. This is likely to develop squall line conditions with a brief period of gusty winds and torrential rain. It will not hang around though and so it is a short, sharp burst of action. Tonight's storms now look likely to only affect the south coast overnight and far south-east tomorrow on GFS and NMM as the area of low pressure producing it has moved southwards on recent runs. It is worth keeping an eye on for anywhere Midlands south though as things can still change and the Met Office still show quite widespread thundery showers breaking out from the North Midlands south. They have a weather warning out for the rain amounts too, but do not mention thunderstorms. Tuesday has some interest on GFS charts too, but this is a long way off yet. Elsewhere for today we have nothing from Estofex as yet but Convective Weather have a slight chance of thunderstorms http://www.convectiveweather.co.uk/ Nick F also has a forecast out which was released last night with a slight risk of severe storms across the NW and a more general marginal risk. https://forum.netweather.tv/topic/83828-uk-storm-and-severe-convective-forecast/

Sorted it So, what does today have in store. I shall go and check some charts and then come back!

I have seen no less than 4 cells today. Storm number 1 moved just the west of Derby with lots of rumbles but not very much lightning visible. Winds were gusty with the rain though. Storm 2 tracked through almost the same area although a few miles west. I got a few bolts on camera from this one but it appeared to die overhead as a frequent rumbling one headed northwards to my west. This evening I drove under a storm near Newcastle under lyme. It didn't seem very active and so I didn't stop as I had a different cell in my sights. Storm 4 was near to the village of Woore in Cheshire. This made it like night time as it approached around 7:30pm. This was the most active of all the cells with some very bright pink lightning, bolts, thunder, torrential rain and gusty winds. I am hoping everything recorded ok, have not got home yet so can't check. It has been a fun day though, and there may be more over the next couple of days :-)

Ok, heading outside to get a better view

That cell producing lightning is heading straight for Derby

Lightning detected SE of Burton on Trent.... it has started!!!