12z GEFS show a number of runs hitting +20C 850hPa briefly. I guess the short duration would would limit things otherwise we could be looking at 35C at least.

Somewhere like Brogdale, Gravesend, St James Park could certainly do it on day 3 of the mini heat-wave, should it come to any sort of fruition.

Stunning output tonight but the GEM is quite simply staggering. 5 days +15c uppers 3 days +20c uppers and no end in sight at day 10. One of the hottest runs I've ever seen. 

http://www.wetterzentrale.de/pics/Rgem2402.html

This heatwave has sprung up from almost nowhere, plenty of scope for change I guess.

hoping tonight's GFS and tomorrows runs firm up on it.

OK NAVGEM wins! 

http://www.wetterzentrale.de/pics/Rnvg1802.html

All I see there is heat. Needs lot of other info to draw conclusions on precipitation. 

Once it gets really hot then the scope in this country for at least isolated storms is there.

As for this coming from nowhere, well it's not arrived yet and there have been indications, albeit from outliers that something could be brewing in the past few days.

Another key thing about heat is the capacity for a reload should it occur, especially as it'll be from a continental import set up.

The heat in 2003 and 2006 saw this happen.

18z GFS op looks to be similar. 

Where the hell is Stormchaser when you want him! 

http://www.wetterzentrale.de/pics/Rtavn21617.gif

Come off it lol

Wow, I'm lost for words. What a delightfully hot GFS run. Shows 32C here.

This, for me, is my version of when you guys get all excited at the possibility of 5cm of snow in winter. 

And and just as unlikely to come to fruition 

I said "almost" nowhere and nobody takes outliers that seriously, 

Until today the GFS mean barely touched 20C at any point, it has been quite a sudden move to have high pressure build in so strongly and push low pressure systems well to the NW.

The Met Office certainly have not forecast it and still may not happen of course so we will see how they update their mid term forecast later but it is still a surprise heatwave that is on the cards.

Outliers can be useful occasionally, especially when you see a trend in the ensembles showing them increasing. The intensity across the UK wrt uppers has increased as the wind has taken a far more southerly vector rather than the glancing blow scenario.

Some outrageous heat across the continent given the uppers and 34'c as shown on Marcus's chart is perfectly feasible in early July

Whhooooaaaa..check out these ensembles this morning. A significant step towards a significant spell of hot weather ! 

Now maybe I'm being nit-picky, but I can see little signs as to how this can easily go wrong. NAVGEM and GEM showing how this can all flatten and tune into little more than a warmer blip. They were fully on board yesterday.  That annoying little low in the Atlantic could still easily be a thorn in our side  

I fully expect there to be at least some bad runs in the next few days, and there always is when we appear to have a spell of snow on the horizon, and the pessimist in me expects it to just not happen. 

Either way, that heat over Europe won't just get blown away, and if it does got tittus verticus, you would hope there would be other chances. 

Yep, I can understand that but temps in the 30's still being shown

http://www.wetterzentrale.de/pics/Rtavn23417.gif

You could well be in luck

Very good output again this morning IF ECM is correct then 35c will be possible next week. Maybe even the July record could be broken which is 36c I think.

http://www.wetterzentrale.de/pics/Recm1682.html

http://www.wetterzentrale.de/pics/Recm1922.html

20 C here on that map and 15 C in Richardland with vile crud affecting eastern Scotland 😁

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON THURSDAY JUNE 25TH 2015.

THE CURRENT GENERAL SITUATION A weak ridge will be maintained today across Southern Britain while a warm front crosses NE over the North. This is then followed by a cold front moving in from the West across all areas tomorrow.

http://www.wetterzentrale.de/pics/Rtavn001.gif

MODELS-2 WEEK HEADLINE A lot of dry, bright and possibly very warm weather but somewhat more unsettled interludes too with some thundery showers in places.

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow expected to blow East across the UK over the coming days up to and including the weekend. The flow then ridges North over Britain at the same time as troughing South over the Atlantic setting up a Northerly moving jet just to the West of the UK later next week.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational today shows several more days of changeable conditions with occasional rain from troughs moving East interspersed by dry and fine weather. Then pressure builds strongly over and then to the East of the UK next week with rocketing temperatures in a SE flow. Low pressure to the West and SW is shown to spawn thundery showers and storms to Western and some Southern parts later in the week which then is shown to mark a slow decline in conditions and temperatures to a more showery and changeable pattern by the end of the run.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

THE GFS CONTROL The GFS Control run is very similar but with somewhat less influence on the thundery breakdown late next week and the subsequent change to more changeable conditions with a more gentle fall off in temperatures as winds switch from SE to more of a NW or West breeze.

THE GFS CLUSTERS The GFS Clusters today show strong support for High pressure to influence the UK from a position to the East in a weeks time before the gradual return to more Atlantic based winds and some lower pressure sets up for the two week time period.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO UKMO today shows a build of pressure from the South next week transferring to the East with the associated plume nudged further East than was shown on last night's run meaning while warmer and humid across the South and East cooler air is shown to lie close to the West and North with a trough likely to displace the warmth soon after the Day 6 chart with some thundery rain.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts follow the raw data well just hinting at the rise in pressure by 120hrs to support a warm up from the South and setting up a change from the more changeable atlantic based theme currently.

http://www.weathercharts.org/ukmomslp.htm#t120.

GEM GEM shows High pressure ridging up from the South early next week being absorbed by a general rise of pressure to the North. This sets up a SE or East flow across the UK and as the warm and humid air present over the UK destabilises from the South late next week the risk of thundery rain and showers spreading North across the UK increases with time.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM shows a NW to SE split in the weather next week with a lot of very warm and humid air with the risk of storms at time across the South and East while the North and West stay somewhat cooler with the risk of occasional lighter rain at times as the Atlantic holds some influence.

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

ECM ECM this morning shows the battleground next week I highlighted yesterday as High pressure builds North just to the East of the UK setting up a very warm or in the East hot Southerly flow. The cooler Atlantic air will lie close by to the West and this setup could well spawn some severe thunderstorms as the cooler air nudges the hot air out of the East late in the period with a return to more changeable and cooler Atlantic based winds with rain at times in the North and West to end the period.

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows Low pressure close to the NW with very warm air to the SE and where the two meet there will be a strong risk of thundery rain or showers with rather cooler air maintained over NW Britain.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends continue to show a chance of a plume developing close to or just to the East of the UK next week.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 96.6 pts followed by UKMO at 95.4 pts and GFS at 95.3. At 5 days ECM  leads GFS at 85.4 pts with GFS at 82.8 pts and UKMO at 81.6 pts. At 8 days ECM clocks in ahead of GFS at 48.5 over 46.6. Then at Day 10 ECM remains ahead of GFS at 30.4 pts to 23.2 pts.

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig
 

MY THOUGHTS The charts this morning are still indicative that the UK will see it's strongest warm up of the season so far next week but will it be for all. The models are jostling around with a Spanish plume of heat as it is pulled North on rising pressure behind the current series of weak troughs as they move out of the UK to the East by Sunday evening. As pressure builds North and then slowly East hot Southerly or SE winds could be drawn up across the UK. The axis that the plume will lie is crucial to how much of the UK becomes affected by it with some output putting it further East to affect principally just the East and SE while some show all areas sharing in some very warm conditions for a time. Before we get too excited and used to the heat it looks like that after several days it will be displaced by the classic thundery breakdown from the South and SW and there is a strong trend to indicate a return to Atlantic Westerlies and attendant cooler air with rain at times towards the extended end to the output. So although it looks like it may not last too long there is a lot of interest next week not least from the risk of some pyrotechnics from thunderstorms as the cooler air fights back late in the week and no doubt if the breakdown is as marked as some output shows some local flash flooding issues could occur too. All too far out to call of course at the moment so while the pattern unfolds lets look forward to some very warm air on our backs next week as the synoptics finally look more akin to Summer rather than the late Spring or early Autmn cool charts that have blighted our part of the World for so long.

Next update from 08:00 Friday June 26th 2015

Hot/humid and increasingly thundery if the ECM 00z at this range is to be believed.

Navgem and GEM have both toned it down a lot this morning though. GEM doesn't even bring the 15C line across the UK at all any more! This is as close as it gets 

http://www.wetterzentrale.de/pics/Rgem1922.html

Looks like the classic recipe for severe thunderstorms; a plume of hot air being seen off by a cool depression in the SW approaches; the hot air can't retreat to the south and has nowhere to go but up! But the plume has yet to come in from FI - here's hoping. Down with Navgem!