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..and others that don't 1976, 1983, 1994, 1995, 2013

The interesting thing is that this appears to be associated with a Rossby wave packet which ended the UK heat wave last week. The chart below shows after initial amplification over the north Atlantic (start of arrow, top right of diagram), the wave packet crossed Eurasia sending a surge of warmth northwards into the Arctic (Tiksi reached 24.9°C, normal August max 11.1°C) and a northerly flow is contributing to a wet few days for northern Japan (> 3 inches rain in last 24 hours) and the coolest temperatures since early June for some places. In the coming days it's set to lead to a warm up for Alaska and western Canada but then cooling and some early frosts and possibly some snow in it's wake, for more central Canada and towards Hudson Bay. Finally it reinvigorates over the Atlantic and reaches the UK again around the end of next week. (chart courtesy Steven Cavallo http://arctic.som.ou.edu/scavallo/real_time_plots.html)

That's one heck of a frontal wave at 72t forecast time stretching from the deepest Tropics to the Arctic Circle. Try forecasting where the rain will be from that set up. Staying hot over continental Europe this weekend and possibly SE England tapping into some of that heat for a while. Obviously the main frontal activity looks to be further North and West across the British Isles, but where precisely will this mainly occur ( ie ) Will the rain affect Trent Bridge for the start of the next test match or not? Based on the raw output to produce that chart, I would say difficult to forecast right now. C

A quick look at the GEFS and EPS mean 500mb anomalies last evening would indicate no significant changes to the outlook in the short term, Low pressure over the Arctic with twin centers N. Canada and Franz Josepth and no significant amplification of the sub tropical high pressure results in a pretty flat upper westerly over the Atlantic portending the UK weather to be changeable but tending very much to a N/S split. Last evening’s ecm det. run gives a flavour of this. (this could subtly alter if later some ridging occurs in the western Atlantic) One way or tother the upper trough centred east of Iceland will influence the UK weather over the next three or four days, After a clear night in most places the cloud and rain from fronts associated with quite a deep low south of Iceland will effect N. Ireland very early and spread through central, and southern Scotland and northern England during the day all of which will be accompanied by strengthening winds,. Further south a pretty fine day Very much the same scenario overnight and through Saturday, Clearer and windy in northern Scotland but tending cloudy in the rest of Scotland and northern England with the cold front trailing across the country out into the Atlantic where TS Ernesto has merged with another low. The rest of England and Wales are in a weakish warm sector where it will feel quite warm where the sun breaks through with possibly some intermittent rain/drizzle in the west. Overnight Saturday and through Sunday the waving front, including the remnants of Ernesto, track east to be over northern England by 1200 Sunday. A quick overview of the latter as it loses it's oomph And the surface analysis with the rain concentrated in the north and again the very marked N/S temp contrast. Monday and Tuesday are really an illustration of the opening comments as wave depressions swing north east bringing breezy conditions and patchy rain to the north whilst the south remains essentially dry and much warmer . And the NH profile at T120

Great to see the colder 850’s at the end of the run, -16 uppers to usher in autumn as the heat belt gets squeezed back to the mid latitudes.

Evening...A Slippery slope to Autumn as Gfs and Ecm suggest,

Little sign on the 2 available 500 mb anomaly charts I use of any marked change in pattern. No GFS for 2 days now but ECMWF abd NOAA 6-10 show a similar pattern, consistently over the past 2-3 days of a flow just N of W, a day or two of settled weather for sure at times but no prolonged ridging in the next two weeks would be my suggestion based on their outputs. Better the further S and E one lives. Warmth there at times, even a bit humid depending on just where any surface high cell develops temporarily but no prolonged dry and heat. Both show troughing into Europe links below http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

To add to MWB response ^, I've put most of this through Google translate a while back and have come to the following conclusions, anyone please correct me if I've got details wrong. A cluster is a group of runs that meteorologists think are similar for forecasts several days out. Example chart: The colours show geopotential height anomaly at 500mbar (Z500) against 1981-2010 data, a question remains in my mind whether this changes with seasons?, contours show actual Z500 values for one run for each cluster (of runs that are deemed by the guys at ECMWF to be similar). Top left is the time of the run, and the time of the forecast. Top right, the flokkunigluggy thing is the time frames that this particular cluster is valid, before or after there may be more or fewer clusters, depending on what the models are saying. Then the 6 cluster diagrams, in order of decreasing likelihood, these break the 51 ECM ensembles into groups that behave the same way as uncertainty increases as forecast time increases. The numbers above each chart state the number of runs in each cluster, and the percentage, and then the Fulltr. This means 'delegate' so this is the number of the ensemble run which best reflects the cluster as a whole, so it's not an average, it's one run that best fits the defined cluster in the interpretation of ECMWF. Finally, the bottom bit depicts four synoptic patterns relevant to Iceland, and fortunately for us also!, and gives their likelihood from climatology, colour coded as follows: Blue - Positive North Atlantic Oscillation (NAO) Green - Negative NAO Red - (Scandi) Blocking Purple - (Atlantic) Ridge These colours also border the cluster plots above, basically saying (because the plots themselves cover such a small area of the globe) what the wider picture for each cluster is. Hope that helps!

GEFS holding pretty steady today (and seeming very sure of itself!), EPS still all over the place in terms of ensemble spread. The bias adjusted versions shown above are both a couple of days quicker with the mean MJO cycle initiation time compared to the anadjusted. It will be interesting to see how much effect, if anything significant, adjustments to a quicker initiation have on the pattern, if they take place. Sometimes the bias adjustment gets it wrong, though with the Nino base state in place, they currently make sense to me. The 12z operational runs might well be at the sooner end of the scale, as they've allowed more in the way of ridging to reach across Europe, resulting in an extra day (or two in the far south) of warmer than average conditions compared to the preceding runs. There's now some considerable mid-Atlantic amplification being modelled next Thursday or Friday, in response to a major clash of airmasses over NE Canada giving rise to a very large and deep trough that amplifies the downstream pattern just when the ridge would otherwise head east to the UK. I'm unsure whether forcing from the tropics will entirely dictate whether this major storm actually comes about or not; chaotic variability might be enough to make or break it. Even with it coming about, the amplified ridge topples after 1-2 days and we see some ridging toward Scandinavia being explored, so I'm wondering if this could be the final hurdle to get past before we arrive at the return to a Nino-like pattern that has been sought after by heat/thunder enthusiasts ever since the last spell of supportive weather drew to a close on 7th August. If we can get there by next weekend, there will be one week left for the month to redeem itself, or at least make itself seem less of a shortfall on what could feasibly have been (had there not been such a strong CCKW so-timed as to prolong the 'Nino lull'). In many ways, knowing what could have been can be one of the worst things about being a meteorologist, as the most exciting or satisfying outcomes have a habit of not coming about. Much of late Feb through early August was a welcome respite from that! Let's not forget just how much 2018 has given us (well, most of us, depending on your tastes!) .

November-like? It's been about 20 °C here, so not Novemberish at all. I am happy that my lawn is showing signs of green and relieved that the high temperatures that made me feel ill have disappeared for a few days

In the nearer term, the ARGEPE has much of central / southern England above 25C until at least Tuesday (especially from Sunday) and spots in the east up to 27C. Not big fry by the standards of the summer so far, but still in the "very good summer weather" category. For me, clearly a cool down everywhere by next Friday (Scotland sadly never really warming up), but the typical behavior of Atlantic highs modelled weakly at T168 is for them to become flatter and further E by T0. So I'm not buying this NWly. I would expect an improving back holiday weekend, perhaps getting very warm once again by the end of it. A N/S split then for quite a while ahead. North areas mixed with average temps, southern areas get some very usable summer weather right up to the bank holiday perhaps apart from one day at the end of next week.

So to the 12s then and I wonder if this is when we see the uncertainty in the ~10 day timeframe resolved a bit. First out ICON at T132 and T180, ridge, and stronger ridge respectively:

Essentially, the GEFS 6z mean indicates a typical north / south split with the best chance of fine and warm spells further s / se whereas further north by northwest look generally cooler & more changeable / unsettled, occasionally the more unsettled weather slips further SE but as with previous means in the extended range, there is increased support for the azores high to ridge in stronger towards the end of august and potentially continue that way into the early part of the meteorological autumn.☺

Back holiday watch again - clusters not as keen on eastern height rises this morning, but a pretty good set for all except the far NW - looking settled and probably allowing temperatures above average on 4 of the 5 clusters

This latest GFS run on the right-hand side has added a little low running across Wed-Thu (no thanks, had enough of those lately!) hence the quicker arrival of cooler air from the northwest, but I'm watching with interest the way that the trough near Iceland keeps trending west - it's not going to take much more for it to be caught up with by the deep NE Canada trough, potentially becoming an extension of it with a flatter shape that allows ridging to hold on more across S UK Thu-Fri before building back across more during the weekend. Something to keep an eye on, at least. The 06z shows the flatter high even without the full merger of the two troughs. Even with this, though, it looks difficult to avoid another fresh, blustery sort of Friday for the N half of the UK such as is being experienced today. I remain hopeful that the final week of the month will be kinder to those who reside there.

@Mike Poole brilliant analysis of the clusters charts - just to add, the anomalies are according to climatic norms for the particular month. Back to the output : well interesting to see how the models, for once, have pushed back the introduction of cooler air - a few days ago we were thinking Tuesday next week, but now Thursday may be the day for the southern half, UKMO for example Make no mistake, if cloud levels allow, it could be hot next week. The east coast looking particularly good. Onto the clusters, a really good test coming up, because for several runs now it has been promoting a height rise to the east around the end of the bank holiday - last night's chart for 27th below: Strong trough Atlantic VS strong ridge to the east = a fair chance of a southerly draw, at least temporarily. This is still 11 days out though so we'll be interesting to see how close it gets.

Cue the Express saying the UK will be DESTROYED by super hurricane that will being 450MPH winds and will last for 3 YEARS.

Interesting chart at T240 on the GFS 18z Return of summer for the south! . It has that low to the south as per ECM but not in quite the same place. Interesting times once again. Then this at T276: Then it loses the plot, if it ever had it. But that hot late August early September is definitely on the cards, for me it's never been off them!

Feeling a bit autumnal at Fortrose today, max of 16C but the strong wind made it feel a lot cooler. Stayed dry, though plenty of showers going round and only a few glimpses of the sun. Dolphins aplenty at Chanonry Point this evening, best time to go as the parking is quieter (and free - see Highland council have decided to milk the tourist industry by starting to charge for parking during the day).

Hi folks, summer isn't ended, Far from it. GEFS 12z mean here T240: Seems an even stronger signal towards the end of the run!

Some catchup data here to start: 2017 max 21.9 on 19 June 2017 min -0.4 on 12 Dec 2017-18 winter min -3.8 on 1 March so far 2018 extremes 22.5 on 27 July and -3.8 on 1 March ------------------------------- now some additional dry records for CEP data in July -- all 0.0 ten-day totals ending 1-10 July are tied by 2018 -- one 0.1 ten-day min on 4 July (1943) broken by 0.0 in 2018 -- record of 0.1 on 11 July tied by 2018 Dry spell 18 June to 12 July was 25 days, within which 19 June to 10 July all rounded to 0.0, 22 days. This was about the third or fourth longest dry spell ever recorded since 1931.

OK so what do we make of the best models at T240, here's the ECM It does look good for warm settled weather for the south, but the No. 2 performing model the GFS paralell / FV3 at same time - this is the one I'm backing.

Ok..it's low res but run after run from the GEFS mean is showing this!.. a very pleasant anticyclonic end to summer and a summery start to autumn from the GEFS 12z mean.☺

Gosh that’s a loaded statement- I would say most definitely not , we can still have summer like weather in September- but it’s not a summer month definitely Autumn!!

Not sure if this has been posted in here or on another part of the forum, anyway https://www.metoffice.gov.uk/news/releases/2018/a-record-breaking-summer

no i have not retired... im semi retired. i still work. dew is very pretty to look at but still makes everything a mess. a mess to mow, a mess to walk on, and aids fungal growth ....... ..... and fungal spores ARE an allergy to some. funny how all summer youve tried to guilt trip and moan about the heat 'because it causes hayfever' , yet applaud the dew and autumn because it doesnt affect you, but does others... some consistency would be nice...

I had to close my bedroom doors last night I was so cold. I woke up come as well. I do like warm days and cold nights.i think it’s starting to feel autumnal

If only this weather could hang on for another two months, we'd escape the misery provided by endless days of cold, mizzly, mouldy, autumnal murk...If it's nae cold enough to snow, it may as well stay warm?

For the most part, the Gfs 6z operational shows fine and warm weather further s / e / se and the bulk of the changeable / unsettled and cooler weather further n / nw.... BUT then the end of August and start of September look summery for most areas, especially southern uk with the jet further north / northwest and high pressure in control.☺

Packing up the flat ready to go as we exchange in a couple of weeks. Still can't find anywhere to rent or buy with weeks to go which is quite frightening, do the government understand how much inflated house prices affect the quality of life for ordinary folk?. Good lord, the cr*p you find in cupboards..were did that Norwegian troll tooth-pick holder come from????? And why have we taken on a second allotment when we're so busy?? Anyway, it's a lovely day...perfect for doing this sort of thing - fair and 20.c. There's an autumnal feel to the mornings now. Anyone have any thoughts about how early September will pan out weatherwise?I do wonder what winter will be like, we've had some extremes this year for sure. Here's my Emir musk melon btw, unsure when it will be ripe but leaving it till it gets a bit more of a rough skin. Back to it...pthttthtththh.

I thought now that the sun is out again this thread woukd be alive with banter, given that the world didn't end yesterday after all.

try cutting grass for a living, youll soon 'get it'....

The NW’erly has been watered down on this mornings runs. All in all the week ahead looks fine and warm for many, always that bit more unsettled further north. We do get a NW airflow of sorts by Friday but then both the GFS and ECM show the high building back in, to southern parts at least, by the weekend. So no heatwave (although it could temporarily get into the high 20s midweek in the south) but plenty of fine, settled weather with low to mid 20’s for many. Can hardly complain with that.

There's been some very interesting research lately into the impact of a warming climate on the future frequency of SSW's. Here are two such papers. "No robust evidence of future changes in major stratospheric sudden warmings: a multi-model assessment from CCMI" This August 2018 paper looks at the results from the 12 models involved in the 'Chemistry-Climate Model Initiative' and concludes: No statistically significant changes in the frequency of occurrence of SSWs are to be expected in the coming decades and until the end of the 21st century. This result is robust, as it is obtained with three different identification criteria. Other features of SSWs – such as their duration, deceleration of the polar night jet, and the tropospheric precursor wave fluxes – do not change in the future either in the model simulations, in agreement with other studies, such as McLandress and Shepherd (2009) and Bell et al. (2010). The absence of a future change in SSWs is a robust result across all models examined here, regardless of their biases or different representation of the QBO, coupling to the ocean, solar variability, etc. https://www.atmos-chem-phys.net/18/11277/2018/acp-18-11277-2018.pdf On the other hand, this July 2017 paper finds there will be an impact: "More Frequent Sudden Stratospheric Warming Events due to Enhanced MJO Forcing Expected in a Warmer Climate." Given that the MJO is predicted to be stronger in a warmer climate, these results suggest that SSW events may become more frequent, with possible implications on tropospheric high-latitude weather. https://www.seas.harvard.edu/climate/eli/reprints/Kang-Tziperman-2017.pdf

Lovely chill air, in the bedroom this morning!! No, the missus didn't have the hump. Legs felt so cold, had to resort to putting pyjama bottoms on (Sorry, a bit TMI, there). Still had to have bedroom fan on though, as felt very warm initially, last night. The accumulated heat taking for an age, to disperse. Regards, Tom.

I find it interesting that April 1995 and November 1996 stand out so much during the otherwise relatively cool 1990s, and especially as both of those months had a fairly potent spell of northerlies over the UK. November 1996 was especially remarkable as it followed an unusually cool summer which most likely contributed to the near record high Arctic sea ice minimum that year (second only to 1980). Looking over the synoptics both months appeared to have the North Pole often in a sandwich between high pressure over the east Siberian side and low pressure over the Atlantic side, sending air masses from southern and eastern Europe all the way up to the North Pole. Mid-November 1996 also had a warm incursion through the Bering/Chukchi Sea area. The main explanation why the UK nonetheless had cold northerly spells was probably that the anomalous warmth in the Arctic did not really affect the Greenland/Iceland region, and in both cases the UK's air mass was sourced from west of due north. Also July 1998 stands out a bit. Looking at the synoptic charts for that month (which was notoriously cyclonic and unsettled over much of northern Europe) there was a lot of warm continental air being sent around the northern flank of the northern European lows into high latitudes. I had always thought of 2005 as the year when the Arctic saw a step-change, but judging by those monthly rankings, it would appear that the Arctic as a whole saw a marked warming since around 2000, and the marked step-change in 2005 was probably a regional thing in the Barents/Kara region.

If it can hold off until it is actually useful, i.e November onward, then fine by me.

As a coldie, I like to see the expanding cold pool across the high arctic from the end of summer and especially through autumn but at the same time i'm not ready yet to let go of summery potential in mid august and the ecm 12z shows some nice azores ridging and warm fine weather across southern uk, indeed potentially very warm for a time depending on sunshine amounts, there is a cool unsettled blip from the north later next week before high pressure ridges in from the west and temperatures start to rise once again.☺

Nice to see the pretty blue colours back on the ECM . Wonder if the PV will ramp up early this year ??

For comparison with the above, the same charts from Météo France: SON OND NDJ

There have been bigger, and there have been stronger... but it's also going to be a lovely summer storm in the UK, so I figured it's worthy of its own thread.

Much preferred that yellow grass, yellow is my favourite colour and it made for some great photos against the landscapes, moreover it fits the vibe of summer more, after all the grass is always green in the other 9 months and in normal summers. Also for walking in the countryside, dust<mud anyday. Back to boring nothingness from here on out. With that said no complaints about 2018 weather wise, 26th Feb-Last Tuesday was a truly fascinating period of weather.

Bring back Ophelia - all is forgiven

A Big contrast in temperature today and weather type at such a short distance. Whist today at 14.00 hours the maximum temperature was around 30 Celsius in some parts of Paris , some places in London were just 14c. Not very often you see such big a difference, in just over 200 miles. (Gender: Male location Battersea, London)

According to Look East just now, no persistent rainfall expected in the 7 days... Good riddance- it’s summer afterall. Temps averaging 22 -25c - not spectacular but definitely pleasant and useable for those of us that like to get out and about.

Summer heat is fine as long as the heat isn't oppressive and stuck in a never ending pattern, I like variety, I would welcome another heatwave at the end of the month as long as its no longer than a week long and we have some kind of decent breakdown.

Nope. Just means being at work is more bearable.

18.1 to the 15th 2.0 above the 61 to 90 average 1.3 above the 81 to 10 average __________________________________ Current high this month 19.9 to the 6th Current low this month 17.7 to the 1st

Complied some interesting stats. 2018 had both the most mentions (perhaps a recenecy bias however) and most favourited months with the following being netweather favourite of each: January 2010 Feb 2012/2018 March 2013/2018 April 2011 May 2018 June 2018 July 2018 August 2013/2016 September 2016 October 2012 November 2010 December 2010 2010 was the second most mentioned year while 2014 and 2015 had the joint least mentions. May 2018, April 2011, November 2010, December 2010, January 2010 and June 2018 were the favourite individual by mentions. Would be interesting to have a similar thread for the 2000s however I fear that people memory would be worse of these years.

Below I've listed all the days of the top nine Summers (all those of 17.00°C and above) that have exceeded 2018's highest daily mean of 22.5°C on the 27thJuly. 1826 (rank = 2) 27th June (22.8°C) 1846 (rank = 6) None, highest was 22nd June 1846 (22.0°C) 1933 (rank = 9) None, highest was 4th August 1933 (22.2°C) 1947 (rank = 8 ) 3rd June 1947 (23.0°C) 1976 (rank = 1) 28th June 1976 (22.6°C) 1st-7th July 1976 (22.9°C, 22.8°C, 24.6°C, 24.7°C, 23.9°C, 23.3°C, 22.6°C); part of a 12-day run from 26th June – 7th July above 22°C 1983 (rank = 7) 12th, 13th July 1983 (22.6°C, 22.7°C) 1995 (rank = 3) 31st July – 3rd August 1995 (23.4°C, 24.9°C, 24.6°C, 23.4°C) 2003 (rank = 4) 15th, 16th July 2003 (22.6°C, 22.7°C) 5th August 2003 (23.1°C) 9th August 2003 (23.9°C) 2006 (rank = 5) 2nd July 2006 (22.7°C) 19th, 20th July 2006 (24.5°C, 22.7°C) 25th, 26th July 2006 (22.7°C, 23.2°C)