Evening thunder

Lovely day here yesterday, warmer than forecast reached 22.3C here and 23-24C in Exeter. Interesting that Bristol also had the haze, here it was a clear blue sky apart from some cirrus patches and a few bits of alto/cirrocumulus Quite cool last night here, a bit cloudy at first but that's already mostly burnt off and it's warming up. Tomorrow is when the real warmth/heat starts down here with a gentle ENE (offshore) breeze and 27C days forecast (can often be a degree or so higher than forecast too).

Fair enough, here it's mostly clear blue sky with a sea breeze though that hasn't stopped the temperature reaching 21.7c This haze/high cloud people are reporting is strange, as it's not showing up on visible satellite images and on them it looks just as clear as it looks down here, wonder why it's not showing up?

The Satellite images don't show much cloud around NW England at the moment, but it's only forecast to be the low 20's in NW England today anyway. Although actually looking at the Met Office site the maps show onshore/sea breezes in NW England so you could find maxima a bit disappointing there depending on how close to the coast you are unfortunately

On Sunday I'll go for somewhere to just scrape 30C, somewhere in southern counties like Hampshire quite possibly, close to the south coast but not too close to it where sea breezes could develop later and knock the max back a degree or two. Maybe somewhere like Southampton. Or perhaps west/SW of London somewhere like Wisely on Sunday. It won't be anywhere east of London due to a surface flow off the sea though. If it happens next week on lets say Tuesday I'd go for somewhere further west, perhaps somewhere like the Somerset levels or Cheltenham area could get close.

Certainly shouldn't get any low cloud issues down here am pretty sure of that from experience and following the weather for years. Nice to see the ECM re-builds the high over us with slightly warmer uppers again further out.

They don't look too bad though looking at actual values, the mean max doesn't get below 22C all the way until August (also is the climate average max actually as high as 23C there?) Also if Birmigham's highest max in this spell is 25C I'll eat my hat, so maybe those mean graphs underestimate maxima slightly? not saying they aren't good for an overall trend though.

Met Office forecast maps started showing a few 28C's yesterday evening and still show some today for Sunday and Monday: Wouldn't be surprised if it was a degree or two higher locally and the MetO or BBC forecasts seem to think that too.

I'll be happy to take an offshore breeze giving higher temps down here, since usually in hot spells we have onshore winds or sea breezes so are cooler than many places I believe 1976 had a similar set up with in late June that gave the highest June temp ever recorded in the UK at Southampton, but of course with hotter temperatures.

It all depends on location of course, here April 2008 beats March 2013 for snow! and equals it for lowest min temp (and March 2013 had the joint lowest temp of the whole winter season along with 11th December, but that was my highest for any winter season since I began recording (including winters 06/07 and 07/08). Also Jan and Feb both broke my record for the highest ​min temps of any winter month. Anyway sorry should probably get back to Autumn, as for Autumn, I can say or make a forecast based on what I'd like to see, but really have no idea what will happen. What I'd like to see is a very warm/hot spell or two in September, a few rain events though, then cooler more Atlantic weather perhaps first cool nights later on. For the rest of Autumn I'd like some stormy Atlantic weather, but also some quieter spells, and first air frost in October, harder ones in November and the first snow fall. (Basically not too much stagnant high pressure sitting over us later in the season giving benign weather and risking pretty cloudy weather, hopefully high pressure will mainly have crisp polar air).

I had seen a few but I noticed today there were quite a few tortoiseshells fluttering round a small patch of the garden. Last year I remember a similar thread to this and indeed there were hardly any here too, but then later in July and into August with some warmer weather their population seemed to explode and either buddleia (not that big) sometimes had 20+ on at the same time!

yeah agreed best not to take 500mb charts in isolation if you want a complete/more reliable picture. I do think/hope cloud won't be too much of an issue in most places next week (can't rule it out in places particularly with the ECM), but most places should hopefully get more sun than cloud.

That seems a suitable weather type for that chart, looks like a cold relatively clear flow with perhaps some (wintry) showers near eastern coasts. With those colours on those charts it isn't nessesarily blue/green = cloud/precip or orange = sunshine as you've been finding out. They show the geopotential height at 500mb which shows the general placement of upper ridges/troughs. You can get different details at the surface influencing day to day weather in any one place, and of course low pressure can contain clear weather or showery weather at times, cold northerlies with arctic airmasses often leave it clear in inland parts of the UK as shower activity doesn't penetrate that far inland. At least, that's my understanding of it.

Yeah the ECM brings cooler uppers in briefly which could be said to be a bit disappointing, although before this it's uppers are a bit warmer than that of the GFS: I'm thinking there may be a bit of a double peak to this spell, with it perhaps slightly cooler mid week next week. Seems like quite a bit of fine weather to come until well into FI, with the GFS ensembles continuing their theme of remaining above average right until the end: The ECM ensembles also have +12C uppers over the UK at T+240 and an ensemble graph I saw posted earlier today still had 22C max's for Birmingham on the 17th (I think the ECM ensemble max temps underestimate them slightly too, I will be surprised if the max temp from this spell in Birmingham is 25C, and on only one day too). While I respect and take note of longer range forecasts made on here I'm not going to be getting that worried of a more unsettled 'mjo phase 5' type pattern yet, especially as the MJO isn't really shown to reach phase 5 for a while on the forecasts, until mid-late July at least, and I think there's often a lag between MJO and our weather patterns unless i'm mistaken? Also the Met Office don't really see a cooler unsettled outlook later in July for now (not trying to dismiss anyone, just know things can change and don't like to base too much on just one source).

Reached 23c here today, didn't expect it to be this warm, forecast went for 20 or 21c. Lovely afternoon and evening!

GFS 12z brings slightly cooler uppers back (though not like the 00z). The UKMO looks like it might do it a little more than GFS. However still maintaining the very warm mostly sunny theme with great summer weather Also with the GFS uppers, while with elsewhere especially land areas like Europe the uppers warm a tad in the aftternoon like you would expect, the GFS keeps making a cooler pool pop up over the south of the UK instead at 4pm, which then fades away during the night.. Here's an example from tomorrow but it happens on other days through next week too: 11am: 11C uppers over the south http://91.121.16.5/modeles_gfs/runs/2013070412/21-7.GIF?04-12 1pm: perhaps the first sign of the 11C line receding west of London: http://91.121.16.5/modeles_gfs/runs/2013070412/24-7.GIF?04-12 4pm: uppers else where have warmed slightly with a day, except suddenly there's a pool in southern England which is 2C colder: http://91.121.16.5/modeles_gfs/runs/2013070412/27-7.GIF?04-12 This gradually drifts and fills during the evening/night. The location can very a bit but usually southern England has some kind of afternoon reduction, I think the 06Z showed it better later next week. This is probably a bit of a technical question that no one may know, but is this some flaw in the GFS charts/calculations, or is there something odd about the UK? Would this effect max surface temps? or should I just dismiss it.

yeah I think similar of last winter, even March doesn't have a patch on December 2010 here! even if using a relative comparison to the averages. January 2010 and perhaps a couple other spells also easily beat what I saw in March. Kind of rubbed in missing the only truely snowy week at my uni due to a field trip to Spain.. Oh well. If that December mean anomaly chart comes off, it would make winter more worth it compared to the average winter for me!

Some good looking ramps there

Maybe this would be an apt time for a ramp or two in this thread (after all it's in the title). Just a thought.

Bear in mind the GFS shows the uppers lower than the ECM and GEM next week, and by the looks of it, the UKMO though we can't actually see the uppers on this. So it looks like the GFS 00Z is on the lower end of the models and ensembles. Maybe not the hottest temp in the last 7 years (June 2011 hit 33C somewhere one day and unlikely to be quite that high), but perhaps the longest spell of 25C+ days for many areas in summer for the last 7 years (although some parts of the SE/E had quite a lot of 25C+ days in summer 2010 so maybe there especially near the east coast 2010 will be warmer) However in general probably the most widespread and longest lasting 25C+ spell since 2006. Perhaps it won't be so good for places like Aberdeen, but it would be very unusual to get the same picture in every location in the UK of course though. Most of the models and ensembles haven't had a big downgrade this morning. Also re other comments about the GFS showing precip, the GFS often over does the CAPE and showers on the precipitation charts under high pressures like this, I wouldn't mind some thundery showers though I expect this would be pretty isolated next week. Edit: GFS 06Z seems to be avoiding these cooler uppers toppling into the UK.

The GFS drop in uppers is supported slightly by its ensembles to a degree around the 10th. Still remaining above average all the way through though which is pretty good, it wouldn't be looking good if the inverse was true. The ECM keeps us in 10C+ uppers and 12C+ uppers in the south and west though, after having the 15C line flirt with the south early next week. then if anything maintains or rebuilds the high later with 15C uppers in the south/west, with the heat locked in right till the end of the run, although a long way off of course: Unlike last night, this morning the ECM is where it's at if you want more of a risk of the highest temps (i.e 30C+ in places) or proper 'heatwave' status, like the weather enthusiast part of me does even though I might personally find the heat a bit uncomfortable.. lol. Although the GFS does also turn up the heat with the 15C line for a bit later in FI (and a thundery low, if only).

Yeah, even though I may find the heat a bit too hot, the weather enthusiast part of me still want's it as hot as possible. That is quite an impressive high for the uppers on that chart, normally I think of a good ball park figure of the difference between 850hpa's and max temps being 15C, but this can vary and at times in the right conditions with sunny days/lightish winds it can be higher, think this could be one of those occasions under this big high pressure area. I also find the temp a degree or two higher than forecast quite often in spells like this, more so with the GFS at least in recent years! I like the ECM mean tonight with the high still holding on decently at 240hrs and uppers of 12C in the south.

That thought did occur to me too, I think it is possible that Ireland records some of the highest temps with some of the warmest 850hpa temps at times. Yes I quite agree, I was hoping the GFS would upgrade uppers from it's 00z run to be similar to the ECM, and indeed it did, so the 'want to see the highest temps recorded' part of me was slightly disappointed when the ECM 12Z reduced them a bit (by no means meant to be a moan or anything though!), but yes probably just slight inter-run variation and think the high 20's will be reached quite widely (even with tonight's ECM perhaps). Even 12-13C uppers could potentially see localised 30C if conditions are right as they did in the SE on the 25th July last year

Personally I don't see what's better about this Evenings ECM compared to this mornings ECM (or the GFS 12Z). Ignoring the uppers the high was also sightly stronger on this mornings run, especially later on. (Still fantastic charts though of course). Edit: if anyone still reads this, forgot to add, much better than last night's ECM later on though!

If we get the kind of uppers shown on the GFS 12Z or the ECM 00z runs for example, I don't think not having a feed off the continent will stop us reaching 30C+ in some spots. For example the end of June 1976 had similar charts with a surface E or NE flow across the south, with uppers a few degrees higher at 16-18C which resulted in temps up to the mid 30's in places like Southampton! It might be a slightly harder on the ECM 12Z though IMO. Of course the locations of the hot spots may be a bit different to that with a continental feed, In this spell based on current charts I'd guess areas around Southampton/Hampshire or neighboring southern counties, or perhaps the Cheltenham area might get the highest temps. For now I'll go for a max of 31C somewhere in one of those areas, although if they get similar uppers or depending on orientation of the high NW or NE England could come close, or the London area if the surface flow from the E/NE there eases later.

The only thing I don't like about the ECM is it has downgraded it's uppers a bit from this morning, typical when the GFS shows them a bit higher now similar to this morning's ECM. So I actually prefer this mornings run if wanting to record the highest temps as it had 15C+ uppers with 16C touching the SW at the beginning and the end of next week. On the 12z actually a sub-10C pool over central areas on the 8th, and the 10th. But still 12-14C uppers on some days (they do touch 15C right at the end of the run in the SE), so still opportunity for high 20's and maybe the odd 30C. Plenty warm enough anyway you could say and still plenty of fantastic summer weather.