Supacell

My weather channel app has gone a bit whappy, forecasting thunderstorms all through Saturday night! I really cannot see that happening. Tuesday looking a possibility though at this stage for a few late season Autumn storms.

I may be clutching at straws here but I am seeing the slight possibility of some thundery activity moving into western parts this evening and then transferring slowly south-eastwards through the night. CAPE is nothing special, neither are other parameters but enough for a couple of weak storms I think. Nowhere can I see any mention of storms though so I may be missing something.

I do keep records and agree that this year has been about average. There have not been many good storm days with a rubbish spring but July produced some great ones. The best year for me was last year and that will take some beating. 2013 had some amazing storms but all within 2 weeks in the Midlands, the rest of the season was not that good. 2006 a very good year too. 2007, 2010, 2011 the worst. This is all since 2004.

I mentioned a couple of days ago the disturbed clouds not far from Melton Mowbray, very near the village of Frisby. This thunderstorm that went on to produce a tornado near to Old Dalby just 2-3 miles further north. This is a speeded up video of the storm as it approached.

I was partly considering leaving work early to head down to the SE to storm chase, I am glad I didn't now. That would have been a very costly bustola! Still a chance something could happen but the risk is fading now I think.

I cannot recall any forecasts showing a storm risk outside of the south-eastern third of the UK so not sure why the disappointment from people outside of this area. For those in this area I think the risk is still there, although I would be inclined now to think that the main risk will be to the SE of London, more especially the likes of Kent, East Sussex and possibly Essex. Still the chance of a surprise further north-west but less likely IMO. I wonder if there will be any thunder in Derby

It is a complicated one but I will attempt an amateur go at what I think will happen. There seems a quite good risk of thunderstorms developing in the afternoon and evening under the influence a low pressure system with tropical storm origins (Henri). Current charts are still at this late stage subject to change as the low moving up from the south may not take the exact track which is currently predicted. There is also still some disparagy between models. However, it would appear that the best chance is south-east of a line from about The Wash to Dorset, behind a band of heavy rain which itself could produce disruptive weather. The strongest CAPE occurs in between about 12noon and 4pm around southern coastal regions along with the far SE and East Anglia. Basically it looks like the further south-east you are the better. There is a lot of moisture caught up with this system and so any thunderstorms that do develop could produce a lot of water in a short space of time. There is also around 20-30knts of deep layer shear available which could help to organise storms that do form. Helicity in the southeast will promote a risk of supercells and a possible tornado risk also. Lightning and hail is also a risk despite lapse rates not being that impressive to my eye. Winds gusting over 50mph generally, not necessarily only attributed to convection. Outside of the risk of thunderstorms there is the risk of widespread very heavy rainfall and gale force gusts of wind and so a risk of flooding and wind damage for most of England, Wales and SE Scotland. NW Scotland and N Ireland look to escape it entirely. A slight change in track could completely change this forecast with the thundery weather remaining on the continent if the track is further east/south or affecting more of us if the track is further west/north.

Lincolnshire is storm county, no doubt about it.

Yes, I have just been reading the posts and accounts elsewhere. Strange to think I was most probably chasing the storm that produced the tornado near Sleaford. Pity I didn't get to witness it!!! I have actually seen reports of 4 possible tornadoes today - Northampton (Duston), Leamington Spa, Sleaford and Tewkesbury! There were certainly some intense storms out there.

After finishing work today at 2pm I headed east to intercept storm cells moving north. I had my eye on the most intense of them which was to the south of Leicester, I met it just to the SW of Melton Mowbray, near to the village of Frisby. There were just one or two flashes of lightning at first but it became more frequent for a while as it moved overhead with some intense rainfall. The clouds looked disturbed as well. I need to check back on my footage but it looked like clouds were moving in different directions into the storm cell. I then chased behind the storm northwards up the A607, turning off towards Belvoir. By this time I was getting close to storm county (Lincolnshire) and the storm became more intense. I parked up and watched the storm over in Grantham direction and it was producing frequent flashes of lightning against a dark grey sky with the occasional flash closer. There was a lot of thunder too. I decided to keep chasing it and followed it all the way up the A1 as it continued to produce a good few flashes of lightning and occasional IC's and CG's. I chased it as far as Lincoln but by now the most intense stuff was to the east, close enough to watch but I was not underneath it and rush hour traffic prevented me from chasing it any further. To be honest, I needed to turn back anyway or I would have ended up chasing it all the way to the North sea. Another successful day storm chasing in 2015 and considering the low likelihood of anything organised I was more than impressed

I am liking the looks of this and will be trying it out tomorrow if I can get out and about among the showers after work.

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.