Ben Sainsbury

I love ConvectiveWeather but whilst the forecast was accurate for many areas, they moved the MDT zone westwards after we had received all our lightning across Bristol, Bath into Wiltshire? Bit like the Met Office as people mentioned, issuing a yellow warning for rain when people already received all their rain and wasn’t getting anymore aha!

Here's an overview of all the lightning strikes during our thundery period over the last 36 hours. We have totaled almost 12,000 strikes! I really didn't expect too much from where I am in Bristol, but boy was I wrong can say I've used all my luck on this one; the loudest thunder I have EVER heard! As a whole CS England done extremely well, whereas North Midlands/NW England unfortunately have done poorly compared to what could have happened. It's quite interesting to note also, that it is incredible to witness such strong elevated storms this early in the season. Whilst elevated storms aren't affected by SST's, generally earlier in the season they cannot prolong their intensity. The last 36 hours couldn't have been more different, as a result of the favourable conditions above the boundary layer. Can only be a good sign for the future... right?

Interesting, so effectively the the upper level winds have prevented the storm from "suffocating itself" but displacing the updrafts and downdraft, prolonging it's intensity and growth in size?

I'm not convinced that what we have just south of Reading is an MCS. Can you explain why it is an MCS, as to me CAPE values are nothing exceptional and lack of DLS and SRH values, result in lack in organisation and structure. Not to add the area of intense precipitation isn't completely huge and lightning activity isn't anything significant. I'm open to learning, which is why I'm asking thanks!

Looking increasingly promising for those ahead of the band of heavy rain and frequent lightning across Gloucester and Wiltshire. Lightning activity should be enhanced within the next few hours through the process of nocturnal cooling, which in effect steepens lapse rates.

If things edge too Far East tonight, I might have to make my first storm chasing trip ever! Very promising

Sat24 shows extremely promising signs at the moment over NW France for tonight. Large developments within a short time frame along with new sferics!

I'm sure many are wondering why with such large values of CAPE and strong heating that many areas aren't experiencing strong thunderstorms. In my POV, high pressure is still too strongly in control. The high begins to move away from 4pm onwards which is when we should see further initiation. Unfortunately we want low pressure when we have storms, as now the high pressure is effectively pushing down on the storm updrafts preventing them from growing to a considerable height for any lightning activity. Hope this clears things up.

The showers formed North of Cardiff are a positive sign for those further NE of North Midlands etc. Further SE however, the main area of showers across South Devon are beginning to peter out. The area of cloud whilst expanding seems to be thinning across these areas at the moment.

We have lift-off, small areas of precipitation have developed over South Wales. (Difficult to tell whether radar glitch or not) Some half decent convection taking place over me here, beginning to build up in height somewhat. Sat24 shows this rapid developments in last 15 minutes.

Well here are the Euro4 for 9pm and midnight. Much of North Wales and West Midlands actually miss out, very different compared to NMM Model. According to Euro4, CS/SE England into East Midlands look a treat.

Whilst I normally have trust in Euro4, I'm rather skeptical for what it producing during the day now. At 9am, they have shown no storms to have initiated at all! And they don't even show any storms to initiate until 3pm across SW/CS England, risk looks a little eastwards compared to various other models.

To simplify some of the forecasts I've seen, I've identified the main periods of what storms to expect across the UK tomorrow. We are looking at 3 periods of storms. Ignore the key in the bottom-left I use these for my own storm forecasts.

I completely understand apologies if I was also harsh! It's difficult to explain, when the conditions are marginal a forecast will always be issued than not. Therefore times like this more times than not the forecast will be wrong, so I agree with you there. Anyhow I like that a lot of forecasts have been produced by a large variety of forecasters this time, provides me with greater confidence. And as a matter of fact to me it seems like an eternity since Nick have issued a "Yellow Thunderstorm Area" so I'm hopeful!

You aren't wrong, but I think it's a little harsh what you're saying. In each and every forecast they produce they outline the risk is very marginal and there's as much as a chance that nothing materialises. So whilst their forecasts have been so called "iffy" lately, surely their recent forecast outlines their confidence for issuing such a high risk level.

I always thought a thunderstorm of a large intensity, could effectively “use up” the atmospheric CAPE?

Unfortunately the other parameters aren't quite there for supercell development. But nevertheless with such large CAPE values (for this time of the year anyway) there will be some prolific lightning.

Quite astonishing and something I rarely see on hi-res models. The Netweather NMM model 12z, caught my eye as a small area of Wales witness significantly lower temperatures than the near surrounding area of which this area moves north over time. Check this chart out for tomorrow at 3pm. This really could only mean one thing... SOMETHING must be causing this; some extremely heavy precipitation. After looking at the following CAPE chart, it was obvious a large area of violent thunderstorms must have formed. If this is to happen, then I would expect some extremely violent and well structured multi-cell/squall like feature to form and move northeastwards tomorrow. Interesting times!

Very dull start, looks like the mist is taking much longer to clear, a little concerned as looks like winds coming off the Bristol Channel towards the Bristol Area.

There is nothing better to me as an "amateur meteorologist" receiving these types of comments. Being 18 and looking to study meteorology these comments are what motivate me to learn more, thank you and hopefully we'll have many more of these events over the coming months.

Sounds reasonable, I've never truly understood how Skew-T data was collected and its accuracy which is why I've never really used it. Looks good though!

Maybe I should've been more clear, the CAPE chart I posted was from the Netweather NMM model, maybe it's time I use the same caution with that model as with the GFS. Are skew-t's really much more accurate over forecast models and if so how do we know? EDIT: Ironically this is the GFS 12z run... Which is the same as the skew-t.

Looks like that's the case, I can't see many showers forming before late afternoon. The fax charts show the trough moving west to east at the spine of the country at midnight into Sunday. Majority of showers should form before that, many being initiated about 6pm ish... Before lasting well into the evening/night. Major risk seems north of M4 anyway according to NMM.

Yet to see any forecasts for any of the storm forecasters at ESTOFEX and ConvectiveWeaher and understandably so. Very limited convection as high pressure strongly in charge we may have to wait until Saturday at the earliest!

I'm going to give my overview of the thunderstorm potential for the next few days up until Sunday. The main thing to note during this period is the dominance of high pressure which significantly reduces the risk of storms, along with lack of moisture and high CAPE values for majority of period. A few definitions for those who are learning I'll quickly go through them. CAPE: Convective Available Potential Energy - Measure of amount of energy for convection, therefore higher CAPE = quicker storm formation and more frequent lightning. DLS: Deep Layer Shear - A measure of wind shear between the mid levels of the atmosphere and surface. High DLS values means storms will become more organised and persistent bringing a greater chance of severe characteristics. SRH: Storm Relative Helicity - Measure of potential for cyclonic updraft rotation. Therefore higher SRH, greater potential of supercelluar characteristics. PW: Precipitable Water - Indicates the amount of moisture within the air. Higher PW greater chance of storm formation but too high and atmosphere becomes saturated. Tomorrow (Thursday): As you see from the graphs below, we are seeing SB CAPE values of 1000J/kg, this is as a result of strong diurnal heating. As a result we see a few storms form across CS England into East Midlands. The Netweather NMM model shows the formation of a convergence zone which set off these storms. It must be noted that whilst the NMM model produces storms, the lack of available moisture (precipitable water) and under the influence of high pressure, I cannot see much potential tomorrow. However if a storm does form, the low PW values along with 30-40knts of DLS, means that any storm may last a long time from its sustained updraft. Lighting amounts will be fairly infrequent. Friday: Friday warrants a similar risk to Thursday. CAPE values are fairly higher stretching towards 1500J/kg, but must be noted this isn't important if there isn't any available moisture. Again the NMM model are very generous with the breakout of storms, however precipitable water values are a little higher so I'd favour Friday over Tomorrow. We also see values of 30-40knts of DLS therefore any storm that does form will see more frequent lightning activity as the updraft will be long-lived. I must stress that even with these favourable parameters given high pressure is in control, we are more likely to see nothing rather than something. My best bet is just north of M4/Bristol Channel across SW Midlands. Saturday: A much greater risk lies on Saturday, at this point high pressure tends to move back away to the east. As you see CAPE values are even higher approaching 1800J/kg, showing the potential for some very frequent lightning. The reason there is a much greater risk of Saturday is because of the much higher precipitable water values, lower pressure (whilst still high) and a well-defined convergence zone. DLS amounts are rather slim for Saturday however, storm relative helicity values which represent the potential for cyclonic motion within an updraft, are pushing towards 150-200m^2s^-2. Therefore any storms on Saturday I expect to form along a line from North Wales towards East Anglia and the London Area, a few storms just North of M4, but lower risk. These storms will exhibit the potential for supercelluar characteristics but these will be relatively short given lack of DLS and may only occur within a tight time frame. All storms will have a relatively short duration but will result in some very frequent lightning. Sunday's potential remains to be seen as charts don't quite reach that time frame but interesting times nevertheless. I hope this have given you an insight on what we could expect this upcoming week. I'm still learning myself all the time so apologies for any errors.