Eagle Eye

Verification from today.

Little bit of convection around this afternoon/early evening.

Convective Outlook️ A trough will head into SE/E England during the morning of Thursday which may bring a few isolated lightning strikes across the Extreme SE, however risk is relatively low. As this tracks W/NW towards Wales, showers are expected to develop across England & Wales alongside instability being present. MU Cape looks to sit around 200-500J/KG across England, which may allow sporadic and isolated lightning, possibly the odd thunderstorm. The risk across Ireland is much greater due to higher amounts of Cape, less saturated as well as convergence zones which will force showers to develop. A SLGHT Risk has been issued as this area involves MU Cape of around 500-800J/KG, convergence zones & most if not all showers will track into the SLGHT zone throughout the afternoon / evening. This may mean places within the SLGHT may see more than 1 thunderstorm throughout Thursday. Lightning may become semi frequent at times possibly affecting the same places more than once. An Area Of Interest (AOI) + LOW risk was issued across W & Central past of Scotland as MU Cape is expected to rise to around 400-700J/KG allowing for intense cell development. Lightning may also become semi frequent within this area, however we aren't to confident on this so we only suspect sporadic lightning will occur .

Convective Outlook️ A low pressure will sit south of Ireland allowing instability to form across Ireland, Midlands into Wales. Heavy cells will form across Ireland bringing the risk of sporadic lightning particularly across W parts. An occluded front will dissipate over the E England which will allow daytime heating to help fuel cells to initiate as well as instability to around 600J/KG which will allow for some sporadic possibly isolated lightning strikes to occur. The risk will then continue tracking W/NW towards Wales & E parts of Ireland which still brings the risk of a few lightning strike s.

We can't do a forecast today but a few thundery showers possible in Ireland and the SW. A low risk though.

Verification.

High risk going well so far.

Reefseeker Latest runs keeping the storms right along the French coast. A few showers overnight but they look weak and rather unthreatening so I don't think we'll see anything at all unfortunately.

Towers going up and collapsing on themselves. Unlikely to see anything here but it's still something to get a picture of anyway.

Not my day for storms today, just a few late evening showers pushing up from France likely but there's a few cumulus towers going up here. Feels very humid, so maybe the showers this evening up from France could deliver something even here.

Upgrade to high risk. No new discussion as I've already done enough. I've re - used yesterday's discussion and tweaked it slightly for the modelling changes today. Convective Outlook️ Two shortwave troughs, one over Ireland and providing energy to Wales and eventually NW England should force widespread clustering of thunderstorms with frequent lightning and 1-1.5 inch hail potential. A small capping is in place meaning that for the first part of the afternoon, until it reaches 23+ degrees and vigorous convection can take place with enough forcing being built up under capping for clustering of storms likely in some form. The main shortwave trough over Wales helps force an ejection of moisture converging towards Wales as the afternoon heat builds. Whereas cooler air is trapped above the capped layer and as the surface heat builds the lapse-rates increase significantly leading to trapped surface buoyancy increasing. The mixed-layer buoyancy also rapidly increases with the mid-upper levels with rapid decreasing Geopotenttial height at the 500+ hPa layers especially. So once the capping is broken then convection is likely to be very vigorous and quickly form. A convergence zone, perhaps two, along the trough wherever it forms is likely. Initiation should take place over northern Wales and a second band in southern Wales, both moving NE, potentially forcing up into one line. The moisture convergence with winds flowing up the Irish sea and also from the SE arrive in the afternoon in NW Wales. This is where models are potentially converging on bringing some of the strongest storms to with especially strong hail potential, perhaps severe level. Flooding possible given the incredible potential for moisture combining here along with orographical forcing. There's slightly weaker moisture advection into southern Wales, with less coming in off the Irish Sea. But much the same risks as this moves NE are likely. It's less likely than the NE Wales risk though and if it gets pulled in too early, it might not go on to hit the Midlands at all. Hence theres still only a moderate risk here. Saturation profiling looks to be where most of the moisture is trapped in the surface layer with the surface wind flow and increasing dewpoints with evaporated moisture trapped at the surface layer and upper-level moisture divergence happening clearing out the moisture before the storms. This is where the capping is helpful and that increases the lightning potential due to less saturation for the profile. This despite cooling upper-levels, the divergence is slightly stronger than the cooling. Scattered showed a and storms are possible to the north and south of the main clustering (s) where forcing may be weaker but the energy is still there, especially in areas around the south Midlands below the southern MCS, where it depends on the forcing strength whether they become part of a cluster or not. There is the potential for formation into a fully fledged MCS, but the relatively weak deep-layer shear may mean that a visible band of storms doesn't form and instead areas of storms close together and merging appears more likely. This merging may induce shifts in momentum where merging cells or nudging cells may interact with a stronger cell, more likely or not if a Supercell could form though as I'm not sure how much budgets affect non-Supercellular storms compared to the merging cells more known momentum inducing interactions, and lead to severe hail and a weak tornado is possible. Along with temporarily increasing lightning potential. But with the lightning looking potentially very frequent, that may not make that much of a difference anyway. These storms should move NE into the late evening and could last into the night in the NE of England. Along with a few afternoon storms clustering up similarly in Scotland potentially as well. But they should be slowly weakening from the late evening onwards as the surface energy potential decreases and environment the storms are pushing into becomes more stabilised and also the severe potential appears to weaken andor fully go out by the late evening. Cells trailing behind the MCS are possible after it's left areas especially on eastern extent as the lapse-rates are allowed to re-strengthen as surface heating is still occurring. Moisture also feeds those trailing cells from the far SW where it combines with lapse-rates in Wales ish area. Rising moisture feeding into the surface heating and colder air feeding lower and lower in the atmosphere but surface heating weaker. Stronger low-level and deep-layer shearing but weaker energy and forcing. Supercell potential would be better if initiation if the MCS is slightly earlier and allowed for better heating, instead it remains about even with the MCS's with the southern part having a Supercellular risk given the rising warm air into the southern portion and open air below allowing a few momentum induced to southern portions of the system with cells combining into the system. Potentially the best hail chance along this portion of the system. Lift with rising motion is increased and energy lifting with that rising motion. Therefore updraft speed is increased and with cells pushing into the southern part of the likely MCS, either one, the increased updraft width will also help hail production and if it weren't for the mess with not knowing where it will be, it would likely have high risk lightning frequency, very frequent lightning possible and more severe risks associated with the southern part of either of these two or combined systems. In eastern Ireland, there's a shortwave trough that converges moisture there on the far western ecrwnt of the Theta-E ejection where WAA should allow for a few storms to form. Weak clustering and fairly frequent lightning are possible but not currently enough support for specific bands of storms for an area of interest to be added. Small hail and heavy rainfall are possible here, but nothing appearing significant. It's essentially a weaker version of the UK risk with less severe potential and similar energy with weaker forcing. Unlikely to be upgraded to a moderate as this looks to be the last update, unless there's a substantial model output upgrade for that area. In the SE of England, there's an area of interest with a sliding lobe of forcing allowing showers from France to push along the forcing band into the far SE. However, given that they're likely to be in the evening and surface based, it's unlikely that any lightning activity will sustain across the channel and instead it's something to keep an eye out on for sporadic lightning and small hail.

Current state of play 2-5 PM initiation Most models initiation in the SW and western Wales moving NE into the late evening. One cluster in northern Wales into NW England on all models, weaker on AROME. Second cluster initially forms in southern Wales, strengthening into the Midlands for a time. Not on all models but on most. Expect frequent lightning from both of the storms. Deep-layer shear stronger for the NW one, quicker upscaling and potentially lasting longer. AROME combines two clusters over Midlands and NW and this is where they're strongest. Cells trailing behind MCS after it's left areas especially on eastern extent as the lapse-&rates are allowed to re-strengthen as surface heating is still occurring. Moisture also feeds those trailing cells from the far SW where it combines with lapse-rates in Wales ish area. Rising moisture feeding into the surface heating and colder air feeding lower and lower in the atmosphere but surface heating weaker. Stronger low-level and deep-layer shearing but weaker energy and forcing. Supercell potential would be better if initiation if the MCS is slightly earlier and allowed for better heating, instead it remains about even with the MCS's with the southern part having a Supercellular risk given the rising warm air into the southern portion and open air below allowing a few momentum induced to southern portions of the system with cells combining into the system. Potentially the best hail chance along this portion of the system. Lift with rising motion is increased and energy lifting with that rising motion. Therefore updraft speed is increased and with cells pushing into the southern part of the likely MCS, either one, the increased updraft width will also help hail production and if it weren't for the mess with not knowing where it will be, it would likely have high risk lightning frequency, very frequent lightning possible and more severe risks associated with the southern part of either of these two or combined systems.

CoventryWeather I suspect we'll know once we get to the 06Z's tomorrow morning. It's only 2 different solutions at least.

Convective Outlook️ Two shortwave troughs, one over Ireland and providing energy to Wales and eventually NW England should force widespread clustering of thunderstorms with frequent lightning and near 1 inch hail potential. A small capping is in place meaning that for the first part of the afternoon, until it reaches 23+ degrees and vigorous convection can take place with enough forcing being built up under capping for clustering of storms likely in some form. The main shortwave trough over Wales helps force an ejection of moisture converging towards Wales as the afternoon heat builds. Whereas cooler air is trapped above the capped layer and as the surface heat builds the lapse-rates increase significantly leading to trapped surface buoyancy increasing. The mixed-layer buoyancy also rapidly increases with the mid-upper levels with rapid decreasing Geopotenttial height at the 500+ hPa layers especially. So once the capping is broken then convection is likely to be very vigorous and quickly form. A convergence zone along the trough wherever it forms (there's still some difference between the models hence why we've kept it to moderate and not gone high risk) specifically is possible. With forcing centering around this area and clustering up of storms into bands where the further east initaiton is, the more likely it is that a second band of clustered storms could follow those behind that first cluster is with favourable conditions behind the first initiation if the AROME 12Z is correct in its' Wales-English border initation with a second line behind it. The moisture convergence with winds flowing up the Irish sea and also from the SE arrive in the afternoon in NW Wales. This is where models are potentially converging on bringing some of the strongest storms to with especially strong hail potential, perhaps severe level. Flooding possible given the incredible potential for moisture combining here along with orographical forcing, but currently not quite enough support for a high risk. However we have gone for an AOI for lightning and also the potential for an upgrade. Saturation profiling looks to be where most of the moisture is trapped in the surface layer with the surface wind flow and increasing dewpoints with evaporated moisture trapped at the surface layer and upper-level moisture divergence happening clearing out the moisture before the storms. This is where the capping is helpful and that increases the lightning potential due to less saturation for the profile. This despite cooling upper-levels, the divergence is slightly stronger than the cooling. Scattered showed a and storms are possible to the north and south of the main clustering where forcing may be weaker but the energy is still there, especially in areas around Southern Wales and the south Midlands, where it depends on the forcing strength whether they become part of a cluster or not. There is the potential for formation into a fully fledged MCS, but the relatively weak deep-layer shear may mean that a visible band of storms doesn't form and instead areas of storms close together and merging appears more likely. This merging may induce shifts in momentum where merging cells or nudging cells may interact with a stronger cell, more likely or not if a Supercell could form though as I'm not sure how much budgets affect non-Supercellular storms compared to the merging cells more known momentum inducing interactions, and lead to severe hail and a weak tornado is possible. Along with temporarily increasing lightning potential. But with the lightning looking potentially very frequent, that may not make that much of a difference anyway. These storms should move NE into the late evening and could last into the night in the NE of England. Along with a few afternoon storms clustering up similarly in Scotland potentially as well. But they should be slowly weakening from the late evening onwards as the surface energy potential decreases and environment the storms are pushing into becomes more stabilised and also the severe potential appears to weaken andor fully go out by the late evening. There is potential for an upgrade to a high risk tomorrow. Depending on trends the lightning frequency looks very much high territory, it just depends how much the models do show the storms to hit an area. There is risk for high risk type lightning frequency across all of the moderate though and especially in the area of interest. In eastern Ireland, there's a shortwave trough that converges moisture there on the far western ecrwnt of the Theta-E ejection where WAA should allow for a few storms to form. Weak clustering and fairly frequent lightning are possible but not currently enough support for specific bands of storms for an area of interest to be added. Small hail and heavy rainfall are possible here, but nothing appearing significant. It's essentially a weaker version of the UK risk with less severe potential and similar energy with weaker forcing. Unlikely to be upgraded to a moderate tomorrow morning unless there's a substantial model output upgrade for that area. In the SE of England, there's the potential for an upgrade to a weak slight risk with a sliding lobe of forcing allowing showers from France to push along the forcing band into the far SE. However, given that they're likely to be in the evening and surface based, it's unlikely that any lightning activity will sustain across the channel and instead it's something to keep an eye out on for sporadic lightning and small hail.

*Stormforce~beka* Probably only on long exposure photography.