Captain Shortwave

ECM ens have a mean 850hpa temperature of 16c across central/southern England for 3 days straight. Pretty noteworthy. At this time of year it isn’t a guarantee of hot weather, if any cloud gets dragged across the UK during the process of building the high then this could remained trapped (unable to properly break up due to the weaker sun strength). However there is certainly scope and a chance of seeing some notably warm weather from the weekend onwards.

The GFS 06z has temperatures remaining in the mid to high twenties up to and including Friday. However the development of that low delivers some awful conditions over Western and Northern England, along with Wales with heavy rain for most of that Friday. That low will need watching if the models now start to agree on its development. Ahead of this there is an outside chance of temperatures pushing towards the 30c late this week.

The biggest uncertainty comes from where the dividing line between some very warm air to our south and the cooler westerlies further north. The south (especially south east) looks good up to and even including Thursday for instance whilst places further north will be closer to normal. The Euros teasing the possibility of cool air continuing to feed into a weak trough to our west, slowing the progress of the cold front in the process. UKMO ECM The GFS and GEM are not buying this at the moment. I was going to call our another erroneous UKMO output but the 500mb profile from the ECM is at least similar enough to not discard developing a thundery low close to the UK and keeping the very warm conditions going for longer.

The ECM is slower in regards to a cold front pushing south east during the middle of next week. Even Thursday has temperatures in the mid twenties towards the south east. Otherwise a lot of reasonable weather with the warmest conditions towards the south where 25/26c (possibly 27c) is possible on most days in week 1. Still a split regarding week 2, but again the ECM operational looks pretty benign with the Atlantic ridge close enough to keep conditions fairly dry albeit cooler than the next few days.

What about this weekend? It looks okay for many and very decent across central/southern England. North west Scotland suffers on Saturday due to a wrap around feature return rain into the region, otherwise most are fine with good sunny spells. Sunday is similar with the north west seeing showers but again the rest of the UK looks decent, average temperatures in the west and above average in central/eastern areas. This just seems like a throwaway comment based on the model output at 8/9 days out that ignores what is happening in the next 72 hours.

So if we are going to see low pressure sinking southwards next week, the position and eventual direction of this evolution needs to be watched. All the models do this but slight changes in the above can lead to a very different end result. GFS Low pressure still fairly significant and sinking over or eventually just to the east of the UK. UKMO The low is weaker and further west, we see continental air pushing back in from the south east. Despite some posts this morning, there is a lot of decent weather on offer, nothing dramatic but some parts of central/southern England could reach 25/26c for the next five days or so. So feeling pleasant enough. Rainfall from the GFS/ECM to day 6 Again for a lot of England, there isn’t that much rain forecast and most of that comes today/tonight. Yes the evolution has been disappointing given what we could have got, but the next 5-7 days don’t look too bad and the evolution beyond this is delicate and could go either way. Edit - Looking at the ECM ens- no support whatsoever for the UKMO solution, a fair number of ensembles tend to build the Atlantic ridge towards the west of the UK with the split being between a weak slow moving cyclonic pattern and a cool north westerly but dry pattern with the ridge taking control.

A cooler day than forecast, mostly thanks to a load of low cloud that rolled in overnight that no models picked up on. The cloud has tended to lift more than break up today, though it is mostly sunny now and temperatures are around average.

Worth noting that the ECM control also brings very hot air up across the south for a time in a similar evolution to the op. But we are far far away from getting this into the reliable timeframe. A lot of reasonable weather in the outlook, as mentioned above the weekend has look decent on most of the output recently and temperatures looks set to hit around 25/26c on both days with rain restricted to the north west and even here it is showers rather than anything persistent. Monday and Tuesday looks similar but showers probably replaced by rain in the north west and probably becoming sunny and a little warmer still in the south. Questions remain regarding anything more significant.

The spike on the 18th/19th is for a rather active cold front that moves through, some heavy and potentially thundery rain for a time. This system may need watching as some models/ensembles develop a fairly deep secondly feature that could bring strong winds (More directed through the Irish Sea and potentially some English Channel coasts. UKMO - The deepest solution The weekend/early next week looks a little flatter this morning, though conditions look warm or very warm throughout the period (mid or even twenties possible on most days). It is just a little disappointing that we cannot seem to be able to tap into a sizeable area of hot air that seems likely to push across a large part of western and Central Europe.

The ECM very close to fully pushing the hottest air our way, probably getting in for a while for the Midlands south at day 7 before cooler air slowly pushes southwards with a weak cold front.

The GFS sees temperatures well into the mid to high 20s on Friday as the front doesn’t arrive until late in the day, this is followed by a mostly fine weekend with only a few showers in the north west with temperatures remaining in the mid twenties. Probably the most optimistic but the other models are far from bad in week 1. It does look like the severe heat across Iberia will push northwards again early next week and it isn’t out of the question that parts of the UK could tap into this airmass. 30c looks unlikely but still not impossible if the front gets held up a bit more and we get a bit more of a southerly influence. Thursday looks decent across most of the country too as the weak ridge is right over the UK.

The models this morning suggest a second attempt at building a more substantial Euro ridge around the day 7 mark after a cold front pushes east during the coming weekend. Given the blocked pattern and the fact that we will be dealing with a low filling, rather than deepening, this one could have a bigger chance of verifying (regarding anything hot). UKMO ECM The outlook looks warm, especially in any sunnier periods. Friday looks to be one day that could deliver something very warm.

Never really getting particularly hot on the ECM as there is too much westerly momentum, as such the hottest air (15c 850s upwards) gets swept away. That said the air pattern doesn’t go that cool either as warm air remains over a good part of the UK and pressure rebuilds from the south once fronts push eastwards on Friday night. I would hold fire on the deepening of that Atlantic low late next week, anything weaker could mean the pattern holds more firmly and the southerly is back on the menu. Worth noting that there isn’t much rainfall on offer away from the north west. The GFS has very little rain for eastern areas through to day 8 and any thing that does appear carries the “thundery breakdown” banner.

The biggest change on the output is that the low to our west by this time next week looks more pronounced instead of a weak cut off system it looks to be forming a deep Atlantic trough. GEM Temperatures hitting 30c across the south by this time next week. Higher on Saturday with a stiff southerly wind. GFS similar

The set up does bring the risk of a very hot south to south easterly developing, the ECM the first operational to really go for it though. The other models are not so bullish but do develop a very warm and humid set up for week 2 with high pressure to our north/north east.

A lot more promise from the models for week 2. Low pressure fills and slowly lifts out with high pressure tending to become more dominant. The process looks slow and it is likely that there could be showers on most days, but otherwise conditions should offer some spells of sunshine and fairly warm temperatures (especially with winds falling light). UKMO day 6 GFS GEM The most notable thing here is that al three are agreeing on a weakening of the jet stream, which should prevent the rather grotty weather of the past few weeks.

The models have flattened the pattern at the end of the week to the point where the front tends to align more south west to north east, as such the warm air (whilst diluted compared to the straight southerly) holds on into Friday, so a chance of high 20s being reached on both Thursday and Friday before a front pushes south east.

The GFS seems to be the very best we can squeeze out of Thursday, managing to get the 16c isotherm in for a time. The other models sheer away the warm air very quickly thanks to that deepening Atlantic low and another low across the Baltic that stalls and never really moves away. It is this squeeze that removes the warm air before we even see weather fronts arrive. The GEM is pretty much the middle ground (12-14c 850s and temperatures reaching the high 20s). That said having the UKMO/ECM agreeing with each other at 84 hours out is not a promising sign, at least we will get a couple of nice days but considering the expanse of warmth to our south and the pattern following on from this, the output is rather underwhelming.

There does seem to be momentum building for a plume towards the end of next week as we see a ridge develop to our east south east (surface high varies between the models) The GFS hits the 30c mark on Thursday and Friday next week, the ECM looks potentially very hot on the Friday with a southerly developing (850s between 16 and 18c). The GEM not as hot but offering something more settle as high pressure builds more over the UK and to the north.

Up to the 9th of June at least here it was pretty chilly (albeit there were a couple of days where there was sunshine or the cool undercut off the North Sea relented a little). Then the 10th of June was like hitting a switch and essentially 25c was reached or surpassed on most days until the end of the month. That is a solid month, yes the North Sea muck was frustrating but this was outweighed by the rest of the month being very good. This is even more reflected by the fact that even north Norfolk was sunnier and warmer that average - despite taking the north east wind full whack in the first week or so. Taken from the SE/East Anglia stats thread courtesy of Staplehurst/Blessed weather

In terms of summer weather we have had been with good weather (June this year and essentially the whole of summer 2022). As we speak July is currently running close to normal, though admittedly the temperatures have been a little underwhelming. Yesterday was my son’s sports day, the sun was out the entire time and the temperature was around 22/23c, not too bad and the rain recently has been welcome because there were signs of stress in some of the plants from the dry spell during June and the preceding months.

Just had a thunderstorm sweep through here. The windy really got up and I do expect some damage in places because we were talking 50-60mph gusts as the storm arrived.

The end of this week appears to be moving towards another brief plume, probably the offering the chance of thundery showers rather than anything particularly hot as the plume is too brief and not overly intense. That said it would take too much of a slow down to effectively repeat the last few days. Temperatures are never overly low this week in the south east, but look fairly poor further north and west with temperatures in the mid or high teens.

Two cells already developed, one over Bedfordshire and one towards the East Midlands (Close to Leicester). Can be seen quite clearly from here, the latter one looks pretty spectacular from this angle.

This is where sometimes the 850s can be a little misleading. Yes next week they are a little below the average, but given the surface temperatures can get to around 20c higher (maximum) than the 850s in favourable conditions (clear skies and strong lapse rates) in mid-summer. Then a showery westerly with 850s of 4-7c can see temperatures reach average or a little above. There is still uncertainty regarding how quickly the low will start to move away, yesterday it seemed like Monday would be when we saw some eastwards momentum, the ECM is now a little slower and the UKMO much slower with the low west of Scotland even by Wednesday.