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One of the most photogenic showers I've seen consistently from start to end in quite a while. It almost reminded me of that famous photo of that microburst in Arizona. Superb back end with the Cb revealing itself completely. The shower falling under the sunshine as well, perfect! YouCut_20240329_155111031.mp4

Best day of the year for photography yesterday for me. A few birds flying by the moon as well if you zoom in.

BREAKING NEWS:- The first Nationwide dry spell , for 9 months ,predicted by the end of this week.....!☺

No chance to see structure, it was torrential before and then just changed to small hail, medium hail and then... 20240328_165520.mp4 20240328_165409.mp4

Pretty convinced this is rotating i just dont know ho to report it to torro

Probably closer to hail here but superb capture whoever caught it!

Hey guys,...you missed me!!! i see tentative signs of things settling down as we go through mid month,...i asked mystic meg,yeah right but i will try to be informative... latest cpc looks predomantly south of west so milder than of late how far can the Azores rigde push north to settle things down is yet to be determined so stay tuned P.S ,i have missed so much in here that i will not go back on reading all the post's and the reason beeing is that my OH is ill and could end up in a wheelchair soon but i hope not,she is suffering ATM from (not comfirmed) MS or sciatica,so bare with me and i will post when i can good night all and take care,you don't know what is next around the corner,...just saying P.S next up,...summer is coming,i am fed up of all this rain it is crazy,...a flip of fortunes to better weather can't come soon enough. good summer to all.

Decent early season storm with a bit of thunder and some of the best mammatus I’ve seen in a while. Soaking wet afterwards though, didn’t really have a plan when the storm came.

The showers continued into sunset and produced some brilliant colours. Mammatus properly made an appearance at last! Superb day and unusual for Coventry to see so much in a day as showers / thunderstorms have a tendency to avoid the city but not in recent days dji_fly_20240329_182442_271_1711738195040_video~2.mp4

Lost count of which shower this is, but my brother got caught under it in a park a few miles east of Coventry and said it had hail, certainly looked like it! The hole in the clouds here caught my eye: Not sure if it's just me but anyone see a sad face with this one? Seen several more photos of mammatus around Birmingham, so I reckon this is the anvil it was on: A nice full rainbow to finish off!

I knew there was going to be some convective activity today but I was under the impression that any storms that developed would be much further west, gutted I wasn't paying attention as I could easily have got to a decent location. Oh well, I did send the drone up for a brief look, not a bad looking storm for march YouCut_20240327_193142229.mp4

Three things stand out this morning from gfs. A drying trend nationwide, that must be the most important thing that stands out. Secondly, a chilly airmass enveloping the UK, bonus plenty of sunshine, especially southeastern Britain. Thirdly, Frost ,will be problematic for just about all nationwide. A lot to cheer about, now the rain train is coming to a halt ,some pleasant Spring like weather on the way, ,no heavy rain , No gales , and bright cheery weather to be had , what's not to like about that! ☺

Wow what a night and morning!!!! Snow settling in plymouth for a time (gone now) and thick thick snow on the moor on the 28th March. To those who say it can't snow in March you are talking rubbish!!! It was perfect conditions a pivoting front cold air no wind. Started raining at 3c just watched the temperature continuously falling. At 2c some thick looking rain. At 1.5c wet snow. At 1c the biggest flakes I've ever seen. Temperature eventually fell to -0.3c. Amazing evaporative cooling event!

Looking at the next ten days, which cover the middle third of April, t’s good to see the relevant part of the annual cycle, in the form of the springtime waning of the PV, well underway. It is happening a bit later than the last couple of years, but is striking nonetheless, here on both the 0z ECM operational run and ensemble mean, day 1 - 10 animations, the PV very much on the wane, being nibbled away by evolving mid-latitude ridges, with the core PV diminished and returning from the Siberian Arctic to the pole. This leaves us with a solidly meridional 5-wave hemispheric pattern by day 10, shown nicely on the op and mean anomalies, ridges by then through western North America, up through the eastern seaboard, Western Europe, Kazakhstan up into Siberia, and the far east of Russia. The picture for the UK and Ireland alternates from seeing a shallow ridge over the next few days, to being under the influence of an active low pressure system passing through with the trough around days 5-6, before the arrival of a better amplified ridge by day 9-10 as the more meridional pattern firms up. Day 10 provides a convenient juncture for the UK and Ireland for showing the potential for something more settled getting a bit further north to be more widely shared, op and mean again. However, it looks very much like it’s a snapshot in a slow but steady revolution of the 5-wave ridge / trough pattern around the pole, with approximately 4 days appearing to be the current phase for the ridge to trough transition, hinting at a period of drier, brighter spells of 3-4 days alternating with more changeable spells of 3-4 days. A much more normal and much more pleasant a pattern on view as spring more clearly shows its hand.

Quite possibly an elevated Supercell and some of my favourite photos I've ever taken. It was incredibly menacing as it moved it. Lots of striations showed themselves occasionally.

After literally months of rain and slate grey skies there is hope of a change this morning. EC mean day 9 ...

2nd storm of the year. Died off as it got close but excellent shelf structure and really frequent lightning for a time. Happy with the Timelapse as well. MAH01593.mov GOPR0758.mov

Had really heavy downpour little while ago. Some strikes SE of Macc, but too far away to hear. Nice show of mammatus on it's back edge as the shower cleared.

Hats off to the models. They had picked up on the deepening trough in the nearby Atlantic on the run-up to Easter about a week ago. Not a great outcome in terms of the weather, but the UK and Ireland in the box seat for observing some industrious cyclogenesis over the next 4 days, here on the 0z ECM op. Interesting to see the two packets of low heights dropping out of northeast Canada, the second one really packing a punch and deepening the low pressure to around 965mb, as it spins around nearby giving us all a good wallop, centred to the northwest of Ireland by Thursday. The 0z ECM mean anomaly chart for day 5, Good Friday, shows the problem for the Easter holiday in the form of the trapped trough, held firmly in place for several days by a bank of heights pushing up over the western half of the Atlantic and the other bank stubbornly holding on over the eastern half of Europe. The western Atlantic heights look to ultimately prove the stronger, migrating north to Greenland by day 10, squeezing the trough to the north through the Norwegian Sea as the eastern European heights get slowly nudged into Russia, allowing the surface low to move through to Germany, bringing the UK and Ireland into a northeasterly flow. So looking like we’ll eventually get rid of the poorly timed unsettled spell for something a bit drier and chillier. Yes, hats off to the models but I’ll definitely be keeping my hat on. At this time of the year in particular, with the full range of weather that the spring can offer, the choice of hat is indeed a valuable indicator of how it’s going. Clearly far too early for the time being to venture to the apparel shown on the left, looks like I’ll be sticking with my reliably functional fisherman’s beanie for now. Have a great day.

Just like to the 10 days before Easter the models were in full agreement of a deep Atlantic low just to the west of the UK, now we have solid agreement of an Atlantic high setting up to the west, and maybe shifting east to sit over the UK. Nothing particularly warm in sight at the moment but definately an end to the constant deluge is now pretty much guarenteed...Thank God!

As the great man himself promised, Kathleen is being taken back home again, to be reabsorbed within the PV by day 5, here on the 0z ECM operational run. As a result, for the UK and Ireland, a vastly improving picture over the coming week as heights build northeast from the Azores, temperatures picking up by the end of the week for a while too if the T850s are anything to go by. Before exiting east, Kathleen ejects some energy westward to help the next system along, this one passing east further north through Iceland, to set up over Scandinavia from day 6 through to day 10. The bulk of Kathleen has by then rejoined the PV from the Siberian side, helping it pivot to be elongated down towards the Norwegian Sea, fuelling the dropping of the trough down through Scandinavia, bringing the UK and Ireland into a cold northerly flow for several days. After this rather dramatic phase (following three inches of snow in west Wales last week and three days of gales in the west of Ireland this week!), Kathleen looking to help ultimately deliver something for everyone - a storm, briefly something a bit warmer, followed by some clear Arctic air and the possibility of a quieter, more standard meridional pattern as we head into the second half of April. So I guess it’s only fair to leave the man have the last words: “And when the fields are soft and green I will take you to your home Kathleen”

Hope you all had a great Easter and that the beginning of April finds you in good health. Looking at the models over the last couple of weeks it’s easy to perceive little or no change to the pattern and no respite from low pressure for the UK and Ireland. However, there are slow but important changes consistently creeping in to the Northern Hemisphere profile in the longer ranges. They’ve been in recentruns of the EPS / ECM too, but here we’re looking at the 12z GEFS. At day 5, not much change from the here and now, PV elongated in our direction, with the trough dropping down to our west, and anchored there due to an attractive bump of unseasonably warm heights along with a surface high pressure over the central Mediterranean. Another notable bump of heights up through central North America too, into Hudson Bay, maintaining the tight Bering Sea to eastern Atlantic alignment of the PV. By day 10, we’ve lost the heights heading up through the American Midwest into central Canada, replaced by an upper level trough, allowing the PV to fill out west, so we get low heights working down into Hudson Bay. As a result the Atlantic jet stream and trough begins to relax north, so though we still have low pressure anchored to our west, it’s further northwest and nowhere near as deep, central pressure about 20mb higher. At the same time, the loss of heights over the Mediterranean should allow easier eastern transfer of frontal systems through Northern Europe, so the setup not near as stuck. The same process continues through to day 16, so much indeed that the PV is now orientated Siberia to Labrador, with a fully fledged trough pointed down into eastern Canada. A good build in heights from Eastern Europe up into northern Scandinavia puts a roof over our heads so that the draught can only get in through the window. The gradual warming out of the Atlantic trough continues with the 1015mb isobar clipping the far south of the UK, high pressure relocating to the Azores, bringing the foundation for a greater chance of some more substantial ridging northeast in time, the models at least now showing signs of beginning to search out a route out of the rut towards a slow but steady improvement by, and more especially after, mid month.

WOW ! Golden hour did not disappoint ! Managed to get in on some of the Mammatus and some beautiful storm structures including some Iridescence and huge anvils. The thunderstorm threat seems to be diminishing now for the near future where cloudy and rainy skies seem likely

Some of the videos stacked from yesterday

Best I managed Captured the backend of the cell here: Second March in a row now with a thunderstorm here which is decent going after none between March 2015-2022! YouCut_20240328_160548747~3.mp4 20240328_153626~4.mp4

Today was one of those incredibly rare magical moments when you draw the curtains on a normal day (expecting yet more rain) only to find everything is bright white. My 8 year daughter has been waiting all winter for some snow, and then this happens at the end of March! She actually cried with joy.

I just wondered if anyone else has encountered the same problem that I’m having. As some of you may know, I returned from Norway on Tuesday after an incredible fortnight. Everything there was so real: 2 metre lying snow, blizzards, crystal clear skies, northern lights, low temps etc. Now I find that every day I’m staring at the UK model outputs run after run and I just can’t get excited by it any more. I mean, it’s all so inconsequential. So ‘meh.’ There’s just nothing really about UK weather that’s interesting bar the very occasional moment like a deep storm or a heatwave. Winters are as bland as blaaaah-bland can be. I’m not knocking this country, at least I don’t think I am, but when you come back from somewhere where the weather is so real it just makes all this seem like nonsense. I really really hope this won’t get deleted because it is about the model outputs. Maybe it might help us all to stop having squabbles about this or that model run when, really, nothing happens here of any great consequence (any more). xx

This is at Norwich at 3.45pm just had some big lightning and hail from this heavy shower.

Thank God the 00z runs are moving towards HP having more influence from mid month. It's hardly stopped raining since October in the North west....absolutely appalling 6 months of Atlantic dominated weather.

Great mammatus here too

This is getting a bit too much for me now. Another shower bypassing just east of here. Tried its best to produce some mammatus but couldn't quite get there. A short clip just before it went on to give a rainbow segment dji_fly_20240329_163328_246_1711731009634_video~2.mp4 More stuff coming In from the south west as well though looks to have weakened on radar in the last half hour.

Worth just mentioning I think how remarkable (in a negative way, if you want dry weather!) recent weather patterns have been. Here is the NCEP reanalysis chart for March sea level pressure so far. We're over 10mb below the average. Absolutely ridiculous. At the centre of a giant blob of low. Next, all of February and March combined. Still 8mb below average. It genuinely isn't an exaggeration to say that we've been having probably the most unsettled weather in the entire Northern Hemisphere since the start of February. And since I have a feeling someone would ask for this one if I didn't post it, here is the sea level pressure since the start of July 2023. Again, the UK and Ireland amongst the most unsettled places in the entire Northern Hemisphere. This is why I find it hard to believe this pattern will go on much longer, having had a look at this. We can't keep on being target practice for the most unsettled conditions in the entire Northern Hemisphere. At some point, the larger scale pattern will change.

Pea sized hail, possibly weakly marble sized here, loud thunder and rather frequent lightning. Left a deposit of hail on the ground. Weren't recording at the time but perhaps some weak rotation as it passed over. What a way to start convective season!

Decent convective skies this afternoon. Rain/hail curtains and squally winds.

No hail here but some lovely cloudscapes once again this afternoon, with a brief vibrant rainbow as the showers zoomed past. Distant shower: New showers approaching from west / south west, I think the second photo is facing more north though, part of that shower line still: Then the back end of those newer showers:

There’s often comment on here regarding the reduced reliability of the models past a given timeframe. 5 days is often stated as the point at which models become unreliable. Studying the ECMWF web pages, it would appear to be a good deal more nuanced than this. They publish charts showing the “Continuous ranked probability skill scores (CRPSS) of forecasts of upper-air parameters by TIGGE centres”, with the following notes about the score being used: The Continuous Ranked Probability Skill Score (CRPSS) is a measure of how good forecasts are in matching observed outcomes. Where: CRPSS = 1 the forecast has perfect skill compared to climatology - forecast beneficial; CRPSS = 0 the forecast has no skill compared to climatology) - forecast has no benefit over climatology; CRPSS = a negative value the forecast is less accurate than climatology - forecast misleading. CRPSS is evaluated by calculating the function CRPSS = 1 − CRPSforecast / CRPSclimat where: Continuous Ranked Probability Score for the forecast (CRPSforecast) is calculated comparing the Cumulative Distribution Functions (CDF) for the forecast against observations (or analyses) over a given period. Continuous Ranked Probability Score for climatology (CRPSclimat) is calculated comparing the Cumulative Distribution Functions (CDF) for the forecast against climatology over the same period. Hersbach, H., 2000: Decomposition of the continuous ranked probability score for ensemble prediction systems. Wea. Forecasting, 15, 559-570. Here’s the link to the paper that ECMWF cite: https://journals.ametsoc.org/view/journals/wefo/15/5/1520-0434_2000_015_0559_dotcrp_2_0_co_2.xml From the cited paper, excerpted: Instead of two options (event occurs or does not occur), the range of the parameter of interest is divided into more classes. In addition, the RPS contains a sense of distance of how far the forecast was found from reality. For a deterministic forecast for instance, the RPS is proportional to the number of classes by which the forecast missed the verifying analysis. Although the choice and number of classes may be prescribed by the specific application, the exact value of RPS will depend on this choice. It is possible to take the limit of an infinite number of classes, each with zero width. This leads to the concept of the continuous ranked probability score (CRPS)…This CRPS has several appealing properties. First of all, it is sensitive to the entire permissible range of the parameter of interest. Second, its definition does not require…the introduction of a number of predefined classes, on which results may depend….Finally, for a deterministic forecast, the CRPS is equal to the mean absolute error (MAE) and, therefore, has a clear interpretation. This is useful because: 1. Rather than the (subjective) right or wrong, we have a graded measure of the extent of deviation from the realised outcome. 2. Any score above zero demonstrates some forecast skill over the assumption of climatology. Here are the CRPSS charts for T850 and 500hPa height for the Northern Hemisphere incorporating data for the winter just ended. At day 5, ECM attains a score of 0.62 for T850 and a score of 0.72 for 500hPa geopotential. The score for heights is higher at day 6 than that for T850s at day 5. The timeframe above the 0.5 CRPSS level (where the forecast matches the observed outcome in more instances than it doesn’t, compared to climatology) corresponds to between day 6 and 7 for T850 and between day 7 and 8 for heights. At day 10, the score is 0.28 for T850 and 0.33 for 500hPa height. Both those scores continue to offer reasonable “value” at day 10, though to be fair, at a level less than half the value offered at day 5. By day 15, the score is around 0.12 for T850 and near 0.15 for 500hPa height, much lower, but still above zero so exhibiting some skill when compared to just assuming climatological norms. The ECMWF appears to put some store in the 0.25 or 25% level, as this is what they use to illustrate the improvement in skill over the last 25 years. This graph is great. It shows the lead time in days before the score drops to 25% and is for T850. The model has the same level of skill at day 10 in 2024 than it did at 5.5 days in 1998. Noticeable too that winter T850s appear to be handled better than summer ones, probably due to the winter PV, with typically fewer meridional episodes and less dramatic fluctuations in the winter as a result. In summary, in our parlance, the models are more “reliable” for longer for predicting heights than they are T850s. For heights, these are typically of sound merit all the way out towards forecast day 8. The reliability drops off steadily from day 0, there is no sudden drop at any point and the forecasts maintain some predictive value when compared with climatological expectations all the way through to day 15, which is presumably why this timeframe is catered for in the outputs. Lastly, and perhaps most excitingly, the models appear to be better now at day 10 than they were 25 years ago at day 6. This all fits very nicely with the general narrative surrounding their use here in the model thread.

Here at day 5 on the 12z GEFS, as we’ve seen several times during the last few months, the hemispheric profile achieves a striking north-south orientation of heights, the PV with its core over Siberia coordinating a Scandinavian trough, which combined with cross-polar heights at the merging of Alaskan and Atlantic ridges, delivers us a handsome northerly flow. But as during the winter, it’s brief. The pattern has no hold. By day 10, the PV relaxes, the Siberian core leaks out west again towards northern Greenland, so the pattern falls lateral again and the reinforcement of the Greenland trough drops a low pressure southeast out of Greenland. The Alaskan heights are squeezed out, and there is a complete reversal over the Atlantic - with a 40+ dam drop in heights over 5 days to the west of the UK and Ireland, we’ve swiftly lost the Atlantic ridge and we’re back into an Atlantic cyclonic pattern heading into Easter. And as during the winter, once it’s set up, this pattern is not brief. By day 15, there are heights to the north but the PV is lateral, and still very much on our side of the pole, preventing a full build, so instead, we get a southerly tracking jet stream brewing up systems carrying a lot of moisture running up from the southwest, through the corridor paradoxically being held in place by the northern heights. It’s as we were then, seemingly too far south for the northern heights to bring us blocked cold, and too far north for the southern heights to send us a proper block, so we get a fleeting Atlantic ridge that can’t form a robust block with the heights to the north, because they themselves lack sufficient traction, followed by the PV and shallow heights to their south then going lateral and serving us up another extended run off the Atlantic. Fair enough to point out that is what we would expect for a temperate Atlantic climate but the unrelenting nature of never more than a few days with any other option on the table, at the moment at least, seems quite grimly exceptional.

Good morning and Happy Easter to all. If we can say that the UK has a storm season then it likely runs from April 1st to September 30th, but the UK weather does not stick to any rules. This last week has seen thunderstorms with lightning displays, large hailstones and gusty winds along with some amazing mammatus displays. Thank you to all that shared your pictures. Let's hope this coming season offers up some of what we want to all of us. So here we go, it's April 1st but I am not going to offer up any April fools jokes . Today actually offers its own risk of some thundery weather, albeit a small one. Numerous heavy showers are likely to break out today across the southern half of the UK. These should develop readily once the sun gets out across Central and Southern England before expanding northwards through the Midlands and possibly as far north as Manchester. Amongst these could be the odd thundery one but will unlikely be organised with very little wind shear on offer. Anyway, keep on chatting and remember to stay on topic and treat each other and the forum with respect. Heres to a good season of 2024. Old thread here: Storms and Convective discussion - November 2023 onwards Chance of storms diminish tomorrow as the air turns much colder with a 50mph northeast wind bringing heavy snow from the east and up to 20-30cm expected across most of the UK.

Eps mean is strongly keen on higher slp in two weeks which is v notable at such a range gefs not too different About time !

The GFS 10-day accumulated precipitation shows a bit more of a traditional NW to SE split tonight. Still some very high totals for W Scotland, NW England and N Wales, but away from those areas, it really doesn't look all that bad, certainly compared to recently. As we move towards the longer range, it's always a dangerous game making any predictions, but the mean signal is still for any cooler NW / N interlude to be on the short and not too severe side of things. As a final note, worth commenting on that absolutely insane GFS control run in deep FI. Couldn't let it go without saying something of course! At around day 12, things look relatively normal - chilly in the north and relatively mild in the south. But what's that over North Africa? Stepping forward to day 14, the plume launches northwards. And this is where we end up at day 15. 20C isotherm just clipping the south coast. 25C possible in London, over 30C in France.

No comment on the models this morning? In a nutshell, we have a nasty little feature tomorrow that'll give many of us cool, windy and damp weather. After that, pressure builds to the south and SE, bringing sunshine and temperatures up to 20c across these areas by Thursday and through the weekend. The ECM then makes more of that NW'erly blast, bring cooler temperatures again by early next week, but the GFS doesn't make too much of that and quickly rebuilds pressure from the west, settling things down nicely. The UKMO only goes out until next Sunday, but looks similar to the GFS in that it looks a lot less primed for a NW'erly in the way that the ECM shows. Step by step, this is what each run shows for tomorrow: Then later this week with the build of pressure to the south and south east: Then towards early next week, here's how each of them deal with the chillier NW'erly: ECM: UKMO only goes out to Sunday: GFS - keeps any NW'erly very brief, with a quick rebuild of high pressure: What about the means: Less bothered about 850's at this stage, so looking at pressure, the GEFS has a short dip before pressure builds again by the middle of next week - graph is for London: ...and for Manchester: The ECM mean unfortunately is less keen on a quick rebuild of high pressure and keeps any rebuild fairly weak: So we can confidently say that tomorrow looks awful for many, then much warmer, sunnier and drier across the south/SE midweek onwards and into the weekend, less so further north and west, then uncertainty over the potency and longevity of the NW'erly and how quickly and to what extent high pressure rebuilds into next week.

Attempting to piece together (as we are inclined to do!), emerging trends of the outputs from different models, here the 12z GEFS and UKMO at day 4: And then, taking it through to day 7: That is one very welcome surge in heights from the southwest early next week, resulting in a 1030mb+ high pressure cell making a visit on the UKMO. A tad optimistic perhaps and probably not that long-lasting in the event, but the contrast is striking and very good to start seeing all the same. Have a good one.

Mini-forecast for Wednesday night using both main Swiss models and the AROME and WRF. On the western edge of an advected theta-E envelope, Wednesday night has the potential for some thunderstorms along the south coast. Strongest Theta-E of the year it appears is very possible. 3CAPE looks to be very strong for night, mostly surface based developments, but perhaps a mix between the two. France surface based storms won't be an issue, and nor does the channel seem to be, as they initiate over the channel with that surface energy. Perhaps pulsing forwards with different bands of showers andor storms rather than specific ones till they hit the coast. This allows for cells to form through the channel and along the coast for the south coast. Mainly in the southwest but does look to extend eastwards throughout the night. They may be parallel to the coast, with the Theta-E envelope or perpendicular to it, but I suspect that developing parallel would allow for better use of moisture. Alternatively, could mean that it stays in higher saturation and lightning is more limited as the moisture-temperature gradient is potentially lower. Buoyancy is still varied with different models. You can especially see the limit of the almost dryline to the north with developments to the south of that. The lifting isn't really an issue here. Saturation is quite high and the column profiling here based off these models looks quite poor away from the southwest and that may significantly limit lightning. Then the other model pushes the drier air over Wales further southeast and that's the better scenario for lightning potential, also may allow a clearing more of the rain thats likely to push earlier. Deep-layer shear is stronger over the SE and central south, with very little over the southwest. Supercellular potential seems unlikely to be honest. Even away from the southwest. Shearing at the low-levels is a completely different story though, the coastal difference and friction may allow for some spin-ups to form depending on the 3CAPE and vorticity as well. Hence the potential for rotation is there. Clearly it's not that significant based off how much could potentially go towards rotation though. Likely not much hooking in the low-level wind profiles then. Some tornadic potential there. Lapse-rates in the SW are also on for hail potential. Though the shearing profiling can be very lowering of that potential for hail. Given previous events this year, that seems to be less of a contentious issue than I would've thought. AROME is more of a different approach with it moving more directly west to east. Still a fairly decent event for early storm season on the AROME though and maybe good signs that we're getting towards proper plume potential where it can make it across the channel with enough energy backing it. Profiles are quite highly saturated, but the mid-levels may lose some saturation and in the hail growth zone as well. That'll lead to better conditions for hail growth and also the downdraft to be stronger, maybe leading to surface wind gusts, but also, the hail more directly forced downwards, once growth occurs, especially best if the downdraft and updraft seperate strongly. Hail may get to near severe or severe status based off that.

The GFS 12z sees a different, though not inconceivable route to high pressure. With such a wad of unusually warm air over Europe for April and a return of the warm SST anomalies around the Azores, it's entirely possible this could promote a ridge of high pressure to develop into a more substatial feature. Day 10 shows the first 20C appearing on the temperature projection map in the London area. I think if we do see high pressure develop from our south it would easily get us into the range of 19-23C providing there is ample clear sky. The sun is getting stronger very quickly and the continent is warm. All very un-April like patterns though, it has to be said. Indeed, the charts look very similar to late January and much of February when persistent high pressure to our south kept us bathed in south-westerly winds. At times (late January) it ridged high enough to bring in inversion cold in the extreme south-east; this time though it's April and that increase in pressure would bring our first proper warm spell of the year. Not from a Scandinavian high like usual though. Indeed, without steering the conversation elsewhere it's got a very "new normal" look to it, though for now it would probably be very welcomed by almost the entire UK... you might even convince me into it! The devil is in the detail though and the previous run had cool N/NW winds for the same date so it is not a guarantee at this time, but a possibility, and as explained, probably not an unlikely possibility with such a loaded atmosphere. Don't send me hateful messages if low pressure is still dominating on the 12th!

Short video of those mammatus clouds last Friday

A good while since I posted in this thread, and the relentless dross continues… I seem to remember saying, what with the late strat reversal, that it would be the final third of April before anything settled and warm/hot took hold. It is really difficult to see any improvement before that. GEFS 12z mean at T300: Everything is continuing to go the wrong way, with the jet on a NW/SE track (black arrow), nowhere near what we need to see to set us on a summer trajectory (red arrow). I remain hopeful that the pattern (with at least some of it related to the stratosphere) will blow itself out by the end of April, two scenarios for you at that point, 1) sudden flip to warm/hot, 2) a slower burner, gradual improvement, which still means most of spring will have been unremittingly rubbish. My money is still on 1) but there’s no sign of it in the models yet…maybe see it in the outer reaches after another week?

Seems like a lot of us are getting treated to some lovely mammatus. No thunder heard from this beast though

Some eye candy for those of us who are sun and warmth starved on the latest gfs, hopefully our luck is about to change in April, certainly deserve it.

A spell of drier, more High Pressured dominated weather would be very welcome to be honest, as it seems the Atlantic Lows just want to keep invading the scene. Even though the models are picking up a chillier Polar Maritime/Arctic Maritime flow coming in between the North-West and North during, and throughout, the weekend, it should bring some brighter weather conditions with it, especially towards Eastern areas of the UK. (However, showers could become a bit more concentrated towards Eastern parts on Sunday with the possibility of the flow turning more North-North-Westerly to Northerly). So, showers would be the feature of this setup along with the sunny spells. And with the strong March sunshine it could fuel some quite beefy showers at times. Wintry for the hills and possibility to some lower levels, too, particularly during Saturday, as models in various forms, especially the GFS, show a strip of -5/-6*C 850 hPa temperatures filtering East through parts of the UK from the Northern Atlantic: So showers of rain, sleet, graupel and particularly over high ground/hills, snow, between Friday (perhaps with some morning rain lingering for a time over Central and/or South-Eastern/Eastern areas beforehand on Friday) and Sunday. Again can imagine there would be some decent sunny spells between at times, and away from the chilly wind, it could feel reasonably pleasant/Spring-like in the sunshine. (Although you may still need to wrap up, somewhat, particularly those exposed to the winds over over Western/North-Western areas and over high ground ) (Formerly DiagonalRedLine)

Excellent Taking all the following points and composites in the above post we are seeing the manner in which the upcoming pattern shifts will transpire. Starting at these focal points here we see as expected an above average temperature setup extending from Africa through parts of Europe with significantly above average temperatures at surface and upper levels perhaps some temperature records. Here's the Rossby Wave Break Event with the high pressure and dual cut off lows As the High ridges into the UK and Ireland this brings a period of significantly above average temperatures at surface and upper levels, perhaps enough for some temperature records at these levels Into the 22nd we start to see quite a significant pattern shift. As a system which began as the troughing across Canada across the Great Lakes and currently into the Canadian Maritimes per MJO feedback as discussed, begins to move over the Atlantic high this will bring stormy winds particularly toward the Faroe Islands with an accompanying strong Jet Streak and as this system continues Eastward these stronger winds will begin to extend into the UK During the 22nd we'll see a cold front moving through and this begins the pattern shift to that of a colder pattern during week 4 of March. As thickness levels lower and with the 528 dam and below air being present across the UK and Ireland this will cause precip to turn wintry with a risk of snow for all regions of the UK and Ireland ie Ireland, Scotland, Wales and England with most across higher elevations though mixing even to low levels cannot be discounted, probably a setup where West and Northwest Scotland does well for snowfall. Similar to the snowfall risk areas the frost risk will be most prominent further Northwest and North though all areas of the UK and Ireland seeing below average temperatures at surface and upper levels. This initial storm system will produce significant snow events across Iceland and Norway. As this system descends it will bring a new significant snow event for the Alps.. Swiss Alps especially and a heightened risk of a heavy precip event into Slovenia which could be rain and or snow so a risk of flash flooding needs considering, these events are from the 23rd through 26th. In roughly a weeks time we will start to see the feedback of ongoing MJO progression across the Pacific, phases 6 and 7 with new trough developments from Greenland tilted negatively toward the west of Ireland and the Atlantic We'll begin to see an increasing influence from blocking further East which could push the Atlantic trough further west and perhaps an opportunity for a plume type setup given past experience and the time of year becoming more supportive. So we're seeing a below average temperature setup for week 4 of March This is also ongoing feedback from the IOBW warm phase which supports a colder setup during March. Also factoring in the overall season of stratospheric developments including multiple stratospheric warming events which I'd like to revisit my comments here This was a significant SSW event with a significant reversal of zonal winds 10hpa values exceeding -20 m/s Plus a reversal at 50hpa Given recent and current MJO progression paired onto weak vortex events again further excellent and expected correlation Impressive cold setup this with multiple minus double digit temperatures in Iceland and Scandinavia which are of particular note. Cheers KW