Ben Sainsbury

AROME has now pulled away from any activity whatsoever tomorrow, NMM also producing only one thunderstorm within the next 36 hours. Appears to be nothing more than a marginal to slight risk at the moment.

MU Cape looks to be in and around 300-500J/Kg, some reasonable DLS too of around 10m/s and lapse rates aren't too impressive but nevertheless some sporadic lightning, maybe a touch more frequent in the strongest cells but I wouldn't expect too much. Storms likely to organise into line segments if they do form.

I understand where you are coming from but you have to remember that the GFS and ECM are both low resolution models. AROME is actually on it's own of all the high resolution models with by far the most widespread activity. In comparison (all high-res models but ARPEGE kinda) UKV, EURO4, ICON, ARPEGE & NMM (to some degree) all show little to no activity tomorrow. Even the GFS looks a knife-edge. Despite that I'm a big fan of AROME so you never know. I don't understand this "PPN charts won't be the best indication" either, you're right in saying they aren't particularly useful for the amount of precipitation that reaches the ground but the greatest lightning activity is associated with the strongest radar returns so if there is no heavy precipitation appearing on UKV/EURO4 then that means no lightning activity regardless of whether it's surface based or elevated.

Latest EURO4 supports the latest UKV with no elevated nor surface based activity for Thursday.

Sorry to put a downer on things but I'm quite disappointed by this mornings output. Intensity and distribution of storms seems to really have shunted east and definitely has been toned down overnight. I was all for chasing tomorrow but I don't think I will anymore unless CW issue a MDT. Hopefully we see improvements on today's runs.

NMM actually supportive of this, some decent instability around actually.

Technically is tomorrow since it's 20 past midnight, but yeah I get you I've just changed the wording.

EURO4 18z indicative of a marginally severe surface based thunderstorm across Norfolk Thursday mid-afternoon.

Yessss AROME in line with EURO4, UKV & NMM. Makes me feel a lot better. ARPEGE a touch better too!

Definitely will be strong gusts associated, would imagine we will have a nice storm structure too, gust front etc.

ICON 12z showed hardly any precipitation at all, so the fact the ICON 18z has shown heavier more widespread precipitation is good! I don't see the negativity regarding the UKV 18z compared to the 15z seems anywhere from CS England to SE to EA may see something? 18z is very similar if anything a touch west.

Why?

Oh WOW! An extraordinary difference on the UKV 15z and whilst first glance looks impressive it's much worse than the 12z regarding severe potential. Trough seems to pass through much quicker and as a result we actually have an eruption of intense elevated storms across CS England towards the SE but a much lower risk of surface based convection with very small SB Cape values.

No-one can be sure yet what's going to happen so every opinion is valid! The trend of less elevated convection is something that is talked about by Tony Gilbert over on UKWW. He said that the less elevated convection during early morning then the higher the risk of severe/marginally severe surface based storms later in the day so. Interesting read: Convective Outlook Thurs 21st May 2020 - WWW.UKWEATHERWORLD.CO.UK Slight Risk of Severe Thunderstorms Central and Eastern UK 06z-18z Ironically initially started this...

A positive run by the EURO4 12z and is supportive of the UKV & NMM so far. Initiation looks to take place from around 10am from Reading eastwards. Despite there being an eastward shift in most of the models it is definitely a positive sign that the higher resolution models of EURO4, NMM and UKV all show thundery activity on Thursday. I think if the AROME also shows a similar scenario once it comes into view then I can definitely have more confidence. If AROME does come in-line then I'd back EURO4, AROME, NMM & UKV > GFS, ECM, ICON & ARPEGE any day. EURO4 12z below:

Showers/Storms a little more widespread on the UKV 12z run, though CAPE values are marginally less than before.

Yeah I suggest some of you should have a read at Nick F's guide to UK Thunderstorms. Provides a great understanding about some of the basics and types of thunderstorms. Which you can find here:

Yeah the latest UKV is not convincing by any means. Appears to be an increased risk of elevated storms originally across the SE and then a smaller chance of a stronger surface based storm across East Anglia into the afternoon. A lot of the SB Cape appears to be confined to the far E/SE now.

My only worry remains that the pressure lies very high throughout Thursday (~1020hPa) and as a result both ICON-EU and ARPEGE not showing any thundery activity at all. ICON-EU suppressing any convection with pressure exceeding 1022hPa, ARPEGE ~ 1020hPa NetWx somewhat below 1020hPa hence more widespread thundery activity.

UKV 15z looking even more impressive but shows that Lincolnshire might well be the best spot! Initiation looks to take place across CS England between 6-9am. Only 66 hours to go! 9am: 12pm: 3pm:

I don't know what the ICON 12z is on tonight but I love it!

Judging by the latest NetWx 12z run definitely a slight westward shift in instability and precipitation. Looking like an M4 Corridor northwards event again, so potentially Oliver!

Thanks for info! I've never actually been anywhere North of London/East Anglia & Lincolnshire so will definitely be a new experience and this will come very handy!

Obviously I really appreciate Nick's storm forecasts here on Netweather but for my general in-experience my rule of thumb is to only go storm chasing if Dan on ConvectiveWeather issues a Moderate particularly if the area of storms is over the East of the UK. If everything stays together I'm very tempted to make the drive down the M4 and stop off at my Uni house before deciding on next move.

Thanks! From my understanding the NetWx model is a form of the NMM model if I'm right?