There's a risk of elevated storms forming in the SE overnight as well as some weaker storms in the midlands and perhaps into the north, however the main show is looking likely to be during Thursday afternoon where scattered severe storms are possible. There's also a risk of hail and flash flooding. Wednesday night, a Theta-E plume advect into the S/SE, bringing with it 1000+ J/KG of MUCAPE and some fairly strong PBL buoyancy. There's the potential for 2000+ J/KG of MUCAPE in the right situation, but mostly it maxes out at around 1200 J/KG near the coast and 1500 J/KG in the channel. However, dry PBL profiling, with weak forcing means that ascent is difficult to begin unless a trigger can be formed. There's potentially the development of a stalled convergence zone just off the coast of northern France late Wednesday evening that forms an MCS pushing northeastwards overnight as the winds turn more towards the north. However, it's mostly just the ECM that has this. Due to the moisture advection, I wouldn't rule it out even though most models can't find a trigger as of now. Fairly strong DLS should allow for upscaling of whatever does form and also allow it to last longer, potentially helping anything that does form to reach 30,000+ feet tall. Along with a hail risk given the large amount of energy and the favourably shaped hodograph. Large moisture content in the air mass risks flash flooding if a trigger can form storms. Frequent lightning would be likely if storms break out, but it's mostly a low 10% risk of occuring, because of how incredibly conditional it is. Further north, there's weaker MUCAPE, 800+ J/KG on the models that have 2000+ J/KG in the other overnight risk, 100+ J/KG in the weaker models. But with stronger forcing and enough moisture to allow for some elevated showers and storms to form. But weaker DLS may keep them from forming into organised convection. Lightning is likely to be sporadic unless it manages to form into a fully fledged MCS, but given there's still a fair amount of moisture content, flash flooding is a risk. Then during the afternoon, as the ejection of moisture from the south continues, surface heating should allow widespread 1000+ J/KG and fairly widespread 1500+ J/KG of SBCAPE. The AROME is particularly intense with significant areas of the country in 2000+ J/KG of SBCAPE. Either way, scattered severe storms initially in the afternoon, becoming more widespread by mid afternoon into the evening appear likely. Most of the country could see see storms but it's mainly the south and the midlands thst have the highest risk. The surface heating trigger should be good enough to form storms in most scenarios and given the energy, frequent lightning is very likely especially for areas with a slight risk or above. Moderately strong DLS mixing with 100+ J/KG of 3CAPE, potentially exceeding 150+ J/KG of 3CAPE in areas, should allow for severe risks and a chance of a Supercell or two forming. Perhaps also risk an isolated funnel or two, in extreme cases, it may be enough for an isolated tornado or two within higher 3CAPE spots. The main risk area for this could be the SE, but it's more likely to be the midlands portion where the parameters for Supercellular formation are slightly more favourable than surrounding areas. With the large amount of energy and fairly dry initial air parcels, which promote evaporative cooling, there's the chance of severe hail, potentially up to 1-1.5 inches is diameter. Favourable pretty much anywhere, but where the low-level winds are weakest and there's dry air being brought straight up into the system is likely best. Making hail more likely in new cells initially developing that are able to intake dry air from the surroundings. Or, where updraft merge later on, if storms become widespread enough for clustering to occur. Alternatively, if a Supercell does form, it'll intake more of the CAPE, and have the best chance of severe hail. So for most of the day, even at the start, there's risk of severe hail. The large PWAT of 35+ mm does mean that with the increased energy and therefore increased moisture intake compared to most events this year, there's again a risk of flash flooding. Torrential rainfall is possible with most of the storms that form. Storms should fade into the evening as the surface heating weakens, but areas with the strongest DLS may allow for storms to linger into the night. This area changes around on a lot of models but most seem to linger them in East Anglia and eastern parts of the country. But with less severe risks as they fade.