Captain Shortwave

Temperatures already into the mid 20s in places and a high predicted from the arpege of around 27/28c. Plenty of juice hopefully to develop some big downpours. There is some cumulus appears amidst the mid level stuff now.

Sometimes there are moments where despite all the background signals, you can just get unlucky. Next week sees a significant cold pool displace from Northern Canada/Greenland into the North Atlantic flattening the jet stream before the next cycle of amplification which happens to stall the low close to the UK. If the displacement of arctic air didn’t occur we probably would have been looking at a sharper pattern with a ridge retained to our east and low pressure sinking towards Iberia (A theme that has dominated the summer so far) and the Atlantic ridge probably building over the top. A period of mixed weather before conditions settled down with the usual toying with heat to our south. Alas from late next week we will have a period of westerlies. This lamenting should carry a caveat that if the background signals remain mostly favourable, then I suspect we won’t in reality remain in this rut, it will be a question of the route out of the pattern late next week, could low pressure sink south and bring hot weather swiftly back, or will it be slower with low pressure clearing east/south east with the risk of northerly/north easterlies like early June. In short I wouldn’t write off week 2, let alone beyond.

The weekend still looks hot on both days for some. Somewhat dubious of the arpege maxima for Sunday, I think we will be scraping 30c in the south east at best. However even the ECM has the 16c isotherm over parts of the UK on Saturday night.

Quite a bit of mid level instability this morning, enough to make some interesting cloud scapes. probably the best potential this week given that the sea breeze convergence is likely to happen and it will be this that generates slow moving showers.

The big issue today was timing, conditions will rapidly stabilise from the south from now, hence the severe storm risk being early to mid afternoon. There is some convection here, but it doesn’t seem to be particularly explosive.

Finally lost all of the mid and high level stuff and shower clouds are building nicely. Temperatures around 24c now. a few spots of rain coming out of these now, alas they will be Lincolnshire’s prize.

A few promising signs now, a few breaks appearing that do show some more substantial clouds starting to develop, the wind has also fallen light from the south.

Very humid outside now that the earlier rain has cleared. There is a lot of low cloud at the moment with the sun making an appearance occasionally.

The ECM is showing much lower 500mb heights in regards to that low over Iceland. This is lower than any other model by quite a margin too. That would explain the stronger jet stream and the fact that the cold front is much further east than the other output.

GFS/UKMO/GEM It seems the 12z suite is tending to build that ridge further north for for the weekend. It is very hard to see how things pan out post this coming weekend, a lot of the models this morning bulldozed the jet stream straight through the UK, a more amplified ridge may result in a split jet again as the ridge is much harder to move.

Indeed, the models have tended to push heavy rain through the Midlands leaving this part of the country mostly dry. It appears we may need to hope for thundery showers to develop underneath the warm and humid air ahead of that waving cold front. Looks like tomorrow will also see temperatures reach the mid-twenties again, especially if we get some good spells of sunshine.

A nice afternoon with sunny spells and a gentle southwesterly breeze. Temperature is currently 25c.

The GFS again suggests that the whole weekend will be fine and warm for most.

GFS for this coming weekend; It looks like a mostly fine weekend with temperatures well above average for all, the only exception is SW Scotland on Saturday and rain arrives from the west on Sunday evening. Now to be fair the UKMO pushes a front east quicker than the GFS this morning but on last nights runs most were going for a good few days of widespread fine and sunny weather before the jet stream flattens and pushes through the UK. I think it is a bit disingenuous to dismiss some people posting a more positive outlook when frankly there is a lot of decent weather on offer and the worst tends to still keep temperatures above normal. It is worth pointing out that before the weekend, Thursday and Friday also looks to be mostly fine and warm days (Thursday does have a signal for scattered showers through central parts of England but nothing drastic).

ECM for next weekend Looks good for central and eastern areas. It seems to be a case of where any fronts reside in northern areas and how much low cloud might get dragged up from the mid-Atlantic. That said I get the feeling it would only be Western Scotland on that chart that might be disappointing. Temperatures into the high twenties in the south, possibly nudging 30c. I will bank this for Duxford air show. Okay the ECM has raised the stakes for Sunday, 32-33c likely on that chart.

Lots of uncertainty for Tuesday, in particular regarding the risk of rain pushing north/north east out of France in association with a plume of very warm air that will advect our way before being pushing eastwards again. Temperatures on other models struggle to reach 20c due to a lot of rain being modelled. All other days next week look pretty safe to be a couple of degrees above average.

We have our first operational to break off a cold-pool towards Iberia from day 7. It will be interesting to see how it uses this later on.

GFS and UKMO at day 5 The GFS is again flatter (The UKMO looks better than the 00z). Not that this will end bad later on of course. Day 6 Both look good with high pressure centred just to the south east of the UK.

The storm cleared through pretty quickly and to be honest it was a little underwhelming. The strikes did increase as it was moving away. Now we just have thick cloud and light rain.

Only a few rumbles and now we have torrential rain for around five minutes.

The cloud did build but we seem to be fighting some thicker high level cloud now, so if anything the cumulus and larger clouds have tended to disperse.

Temperatures already between 25-27c in places, so exceeding many of the forecasts in terms of temperatures. Cloud starting to bubble up underneath some thin high cloud that has been around all day.

The GFS avoids the big potential warm up seen on the ECM and GEM with a flatter pattern, on the other hand the flatter jet is north enough to create a more extended spell of settled and very warm weather. As we are in June, the heat will simply build in situ with high pressure essentially overhead. So in short, Sunday will be cooler (sub 30c), but would likely see the value reached later at a time where the other models tend to push a cold front eastwards.

Whilst it looks transient in nature, the models do agree on placing a ridge to our east with winds veering more southerly for a time, as well as being extensive enough to bring fine weather for all briefly. As such there is also agreement by next weekend (especially Sunday) that temperatures will push into the low 30s. GFS and GEM ECM (Sunday morning) The 16c isotherm already into the south, so hot on Sunday and potentially on Monday if frontal systems can be prevented from pushing eastwards too quickly. Edit, looks like a breakdown on Monday on the ECM, but probably still hot in places.

The JMA is similar to the UKMO at day 7, the rest of the run has high pressure sat right over the UK. The ECM run looks very similar to the 00z, in fact there is very little in it with the jet stream close enough to bring fronts into the north and west whilst a good part of the England is fine and very warm.