Model Output Discussion - 1st June 2015 12z--------->

[karlos1983]

Not a cool ECM chart at +120, yes maybe the hottest air will be pushed East by the weekend, but it was only really yesterday that gave us a tease of longevity, the models were quite consistent that it would not be mega hot, for a sustained period. At least that's how I remember it.

[Harsh Climate]

All is not lost. On face value it is now ECM/GEM and UKMO v the GFS. Hopefully the gfs is just having one of it's wobbles

[Chris K]

My worry is we still have 3-4 days to get through. It's the classic annoyance of the low pressure to our west and the models potentially(!!) underestimating its influence in how far East it pushes and therefore shrinks the time we see the heat more and more. During some previous occurrences we ended up with nothing more than a glancing puff of hot air across the SE.

Forgive me for being a bit reactive to one run but yesterday's 18z gfs run was also quite progressive. I'm not saying this heatwave won't happen but I'm getting nervous of how widespread it will be and its longevity. Awaiting to see how the rest of today's model outputs look. It will be warming up and the potential for high temps is still there and we have seen sudden upgrades in the past as well

Edited June 27, 2015 by Chris K

[Harsh Climate]

ECM 9/10

 

 

UKMO

 

9/10

 

GEM

 

 

8/10

 

and GFS

 

 

7/10.

 

 

The reason The gfs is least good is simply because the atlantic influence is about there and already in control. For the hotter temperatures we want little wind and for the chance of severe thunderstorms we essentially want to be in a COL.

[Captain Shortwave]

So the models are pretty much repeating the uncertainties regarding how secondary systems interact with the main Atlantic trough. A lot of different solutions at day 6.

ECM

The low is west of Ireland and the solution isn't far off yesterdays 12z.

 

GFS

A shallower system which results in a shallower build of the second wave of heights and heat.

 

UKMO

The system is much slower moving in this run, hence the second build of heat really isn't modelled yet.

 

GEM

Quite similar to the UKMO solution, the low perhaps more developed than it though. The result is actually quite similar to the ECM during the middle to latter range though. 

[Man With Beard]

GEFS ensembles:

http://www.meteociel.fr/modeles/gefs_table.php?x=306&y=141&run=0&ext=fr&mode=0&sort=0

maintain very hot conditions through the middle of next week but have got off the fence with regards to the weekend, and have decided Friday/Saturday hot (but not very), and Sunday sees a return to relatively normal conditions - the number of runs maintaining heat are now quite small.

ECM, on the other hand, is not too dissimilar to last night's incredibly hot run.

Verdict: Hot spell for Wednesday to Friday is still on. Saturday and beyond - not worth making a call yet.

Although Anyweather got slated last night, I agree that with extreme weather you need to wait a bit longer to be certain of the outcome, so worth holding on another day before making a call on whether it will be maxing at 37C or 31C next week.

[bluearmy]

Gfs notable for its progressive nature and ECM for its over amplification. perhaps take Ukmo as the middle ground between them for the time being. Looking beyond the break in the very high temps and one would hope to see the generally fine conditions continue as heights remain generally high

[Harsh Climate]

I don't know about anyone else but I'm not viewing and potential upgrade/downgrade on just how hot it will get. All I'm interested in is the thunderstorm potential!

 

Basically a chart like the gfs pretty much destroys the chances of the classic hot calm day where cumulus clouds rocket up, with slow moving home grown thunderstorms later. 

 

All the gfs offers to me is it  getting very warm/hot before quickly being replaced by less warm conditions as an active front pushes west to east. Yes this would be thundery with a few inbedded thunderstorms, but inmo this is nothing special.. 

[William Grimsley]

Looks like many people are agreeing that the GFS has downgraded this morning especially for my location, we were in the high 20°C's now struggling to get to even the mid 20°C's with only a few days of heat. Hopefully, there's an upgrade in the next run.

 

Also, it looks like to add to this the NetWx-MR has also downgraded the ML CAPE + LI chart and was showing a good 3 days of unstable air and thunderstorm risk and now just Tuesday Night! I hope this isn't a trend if both models have downgraded...

Edited June 27, 2015 by William Grimsley

[mushymanrob]

 

 

As much as people seek heat, they can't be so blind as to not see the elephant in the room RE where we head after this plume event (taking into account potential reloads)??

 

 

 

the elephant in the room?, like the huge build up of heat over france/spain that you and others dismissed a few days ago in favour of the atlantic dominating?.

this heatwave was never expected to be a lengthy affair, its always thought to be less then a week, and earlier it was a one day affair.

 

downgrade?... we still have 5 days of hot uppers and temps over 25c for the bulk of the country... i see no downgrade. its only the timing and nature of the breakdown thats unclear. i note the rolling out ecm currently has the breakdown on sunday, 2 days after the gfs.

the ops too and fro, reading too much into each run perhaps isnt the best way to go. so lets look at the anomaly chart from noaa.

looks pretty good to me! day 6 - 10 mean upper flow looks very condusive to prolonging the heatwave which suggests the gfs ops are out of line and unlikely to be the final solution. this suggests the ecm @ 240 is more likely then the gfs @ 240 , theres no deep scandi low for eg.

ecm                                                        gfs

 

 

further ahead

i see no strong greenland block there, i see the upper flow from the southwest over the uk, and has been mentioned that does continue to allow warmer/hotter southerly incursions.

but the anomalies dont suggest a protracted settled spell over the uk, no high pressure sat on top of us... and CC might well be right regarding the wet spell as obviously a warm southwesterly would deliver warm but unsettled weather. 

 

Edited June 27, 2015 by mushymanrob

[Frosty.]

The Gfs 00z has been described as a massive downgrade and a wobble but looking at these charts and comparing them with the cool, unsettled Atlantic dross we have had in the last few months, the gfs 00z still looks very good with by far the best spell of the summer so far. The reason we don't get 33/35c on this run is due to more widespread thundery showers across the UK, with less storms and more prolonged Sun, the south and east will get into the 90's F.

[William Grimsley]

The Gfs 00z has been described as a massive downgrade and a wobble but looking at these charts and comparing them with the cool, unsettled Atlantic dross we have had in the last few months, the gfs 00z still looks very good with by far the best spell of the summer so far. The reason we don't get 33/35c on this run is due to more widespread thundery showers across the UK, with less storms and more prolonged Sun, the south and east will get into the 90's F.

I have to agree, I've just looked at the latest to previous GFS run and the only real downgrade I can now see is from Thursday onwards. Basically, the GFS on this run is still going for quite a good heatwave but slightly shorter than last run as atlantic front takes hold on Friday and brings in much cooler and fresher air from the west.

[Polar Maritime]

The Models continues to show some very warm/hot weather for the Uk next week, With temps possibly hitting 34c in the S/E by Wednesday. Another run another evolution.. By Sun evening we should have a better idea re local surface Temps. Into week 2 the GFS does show more of an Atlantic influence, As week fronts push up from the W/SW with temps continuing much warmer than of late. But that's a long way off yet, And there's much to be resolved.

 

Edited June 27, 2015 by Polar Maritime

[Summer Sun]

ECM is stunning this morning with lots of heat around and maybe even another plume setting up at the end

 

[Man With Beard]

Re Mushymanrob above:

NOAA anomoly charts showing virtually no change from a week ago. Although I said above how Saturday onwards is too uncertain, the charts Mushy posts suggests to me a fair chance of another notable plume before too long

[seaside 60]

Sorry to be a know all.

However yet again the MO had there own models to use as experience.

Just like the winter, I think they have called it right and not based on all the excitement and depression on here.

It will be hot for a few days and it will get colder and reading between the lines there should be another reload.

However for some reason the highs just cant build in the right place for long enough, looks like a carry on from winter.

The models do show some far to hot weather for most with hopefully some cracking thunderstorms.
 

[Gibby]

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 SATURDAY JUNE 27TH 2015.

 

THE CURRENT GENERAL SITUATION A ridge of High pressure lies across the UK today followed by a warm and cold front crossing East and SE across the UK tonight and tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE Becoming very warm next week with some thundery showers especially in the South and East. Cooler in the NW.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow currently blowing West to East across Southern Britain. Over the next few days the flow buckles North and then sets up a South to North flow close to Western Britain through next week before settling to a SW to NE flow across Britain in Week 2.

 

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

 

GFS OPERATIONAL The GFS Operational today shows a steady warm up over the coming days as very warm air from Spain is directed North and NE to the UK and mainland Europe from Spain. It doesn't last that long though in the UK before cooler air behind thundery troughs moves across the UK towards next weekend and introduces a more changeable Westerly flow with rain at times which gradually settles to a traditional Summer NW/SE split in conditions later in week 2 with the best conditions in the SE.

 

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

 

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

 

THE GFS CONTROL The GFS Control run also shows a two pronged attack of heat from the South in the next week to 10 days. The first one doesn't look like lasting long away from the far East and SE before a thundery trough brings somewhat cooler air in for a time. The second attack next weekend could be more intense in the East before a shift towards the cooler and more changeable Westerly regime shown by the operational is reached later in Week 2, once more most likely preceded by a thundery breakdown.

 

THE GFS CLUSTERS The GFS Clusters today show High pressure having declined by Day 14 with a more Atlantic influence to the UK weather with rain at times especially over the North.

 

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 heat wave or plume moving up from Spain through this week. The East will see the highest temperatures but all areas look like sharing in some very warm and humid conditions this week. Scattered thunderstorms look likely in the West as cooler air attempts to move in off the Atlantic but without much success on this run.

 

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

 

THE FAX CHARTS The Fax Charts support conditions warming up next week as Southerly winds are drawn North from Spain. Humidities do look like being high with the risk of thunderstorms towards the SW shown to be perilously close by the end of the week as destabilisation is shown to the SW at the end of the run.

 

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

 

GEM GEM today shows very warm or hot weather developing through this week with little or no displacement over the rest of the period. Attempts to bring in cooler air at times from the West is shown on occasions but with scattered thunderstorms illustrated too with the high humidity levels for much of the period.

 

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

 

NAVGEM NAVGEM has shifted the heat slightly East of the Uk this morning with NW Europe seeing the most searing temperatures. However, plenty of very warm or hot eather for the South and the East of the UK too is shown with some thundery showers too especially in Western and Central areas later next week and then the SE next weekend..

 

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

 

ECM ECM this morning shows very warm or hot weather across the UK for much of it's 10 day period this morning commencing within the next 72 hours. It maybe that the core of the highest temperatures is somewhat further East today but humidities will be high and the risk of thunderstorms is very obvious this morning as weak upper air disturbances run into the hot air from the South or SW at times without much displacement of the heat. The run ends with a strong Summer anticyclone  re-established across Southern England.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night continues to show slack pressure gradients and very high temperatures across the UK with Low pressure held out in the Atlantic.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends continue to show a plume developing over 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 96.5 pts followed by UKMO at 95.4 pts and GFS at 95.2. At 5 days ECM  leads GFS at 85.3 pts with GFS at 82.9 pts and UKMO at 81.8 pts. At 8 days ECM clocks in ahead of GFS at 49.1 over 46.2. Then at Day 10 ECM remains ahead of GFS at 31.6 pts to 24.6 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 much talked about heatwave is still well and truly on the way this morning with perhaps a shift away from the staggering and blistering heat charts of recent days to the other side of the channel on this morning's run. Nevertheless, temperatures are set to soar as a plume of hot air from Spain crosses France and the UK and NW Europe in general through this coming week. The highest temperatures look like being across the East and SE where 33-35C is likely widely and local records could be at threat. For Western and Central regions the heat will be less intense but very humid in nature with temperatures more likely in the 25-30C bracket under hazy cloud cover and an ever increasing risk of thunderstorms drifting North from Biscay. GFS has then taken a more progressive route this morning displacing the heat for smething much cooler and more changeable through Week 2 with rain at times. ECM though shows much more resilience against any major change with very warm or hot conditions likely for the entire period and suggesting a rebuild of Summer High pressure across the South by Day 10. There is a lot of dotting the I's and crossing the T's in this morning's output but with some confidence we can look forward to a spell of very warm weather with temperatures likely to be the highest for some years in the East and SE. The longevity of the spell is the question mark this morning with some output showing a second surge of heat after a brief relaxation  next weekend. For those that like or don't like thunderstorms there is good and bad news today as there could be many days when thunderstorms are possible and with such heat and humidity around they could be severe locally with a lot of rainfall. No one can deny that recent days model output has been truly staggering with regard to progged temperatures and although I believe we may be spared the very highest temperatures shown by them the charts will need to be watched with interest still as the event creeps ever nearer over the next few days. 

 

Next update from 08:00 Monday June 29th 2015

[William Grimsley]

An amazing post, Gibby! Very interesting indeed! Looks like most models going for a 2 week heatwave still with just the GFS suggesting a breakdown next weekend.

 

[A.J]

Massive downgrade on this mornings 00z GFS run, with a slower weaker push of heat, only Wednesday reaches 30c and its effectively all over by the end of of the week as the Atlantic ploughs in. After several days of such model consistency I find this a worrying development especially following a progressive 18z run. If this is the way things goes and this does turn into another one day wonder it really would be extrmely frustrating from a model watching perspective.

thus the perils of taking each run as gospel......although you are a 'new' member, your posts infer some time spent contributing on model discussion on weather forums, so I'm quite surprised with your opening statement in this post, IMO it's always best to compare like for like runs than consecutive runs........It's just normal variances with the model output, especially when you consider that the trigger low for the hot spell is only just coming onto our radar (so to speak) way out in the west Atlantic. Now that starts to happen, we can watch its evolution and the model outputs more earnestly

Edited June 27, 2015 by ajpoolshark
changed the phrasing

[bluearmy]

perspective people. as steve mentioned the other day, the arrival of the 20c isotherm is as rare in summer as the -15c in winter. it will nearly always be modelled out come verification. at the moment, i would say its > 85% that we see it across se england for around 12/24 hours. however, this is not the sole driver of surface temps. note that ecm gives higher T2M numbers next saturday. this is with lower uppers than wed/thurs. if uppers are in excess of 15c and conditions conducive (ie - long sunny periods or slack and sultry with hazy sunshine), then we will likely continue to see 32c broken. night time mins also a contributory factor as is the shortness of the nights compared to late july and august when we traditionally see the highest summer returns due to SST's etc.

 

into the distance and the developing downstream central asian trough (partly a consequence of the upcoming sceuro ridge) will begin to back wnw and combine with the arctic low to develop a n scandi trough. i expect that will offer the atlantic trough an escape which will return the mean flow over nw europe more wsw than the ssw we see as a result of the mid atlantic trough. that in turn dropping the temps back to normal. europe looks to retain the heights which is where this set up differs to june. no se european trough attracting the  upper trough and allowing the jet to have a sw/ne axis rather than nw/se.  something to look out for is the central asian trough not dislodging the nw scandi heights. that leaves the mid atlantic trough stuck in situ and us in a reloading warm to hot set up.

 

EDIT: just checking the 00z extended and ecm and gefs allow the trough to escape ne whilst gem does as i mentioned above and the mid atlantic trough sinks further s to drive more heat across nw europe. naefs is weighted to gefs so expect the NOAA 8/14 to show a flattening of the upper flow later. will still look decent though.

Edited June 27, 2015 by bluearmy

[Captain Shortwave]

ECM suite pretty satisfied to back the ECM op evolution up to day 7 with hot weather stretching from Wednesday to Saturday with Sunday being the breakdown day.

4 hot or even very hot days in the south with temperatures well above average elsewhere. Certainly decent for the UK.

GEM suite similar so it is just the GFS which is showing something more progressive, it might be right, it might not.

Overall a decent output with a heatwave very much still a decent possibility. Worth noting on the ECM, the 850s for midday Saturday wouldn't be too far off the ones for midweek, 20C likely in the south east given the Sunday morning chart, only a degree or so down from Wednesday/Thursday. 

[h2005__uk__]

Earlier this evening, WeatherPro was going for Wed 32C, Thu 32C, Fri 30C, Sat 27C in London..... it now says Wed 32C, Thu 33C, Fri 32C, Sat 31C.

 

WeatherPro now saying Wed 32C, Thu 33C, Fri 33C, Sat 31C. I know that's just London, but the point is the temps keep getting upgraded.

 

Maybe I shouldn't post this here but it's a model output of sorts and WeatherPro is normally far more accurate than the likes of the MetO/BBC, etc!

Edited June 27, 2015 by h2005uk

[summer blizzard]

It's very much like winter with the models wobbling.. 3 different scenarios..

 

GEM - No breakdown at all..

 

 

Euro - As per the pattern until last night, it's not until the second front on Sunday that the breakdown occurs (though it's hardly cold afterward)..

 

 

GFS - Both the 18z and 0z have Friday's thundery trough doing the job..

 

[Dan the Man]

Quick question - is there an official designation of "hot" or "very hot"? As I guide I tend to use:

 

Very Cold - Minus

Cold - 0-4C.

Chilly - 5-9C

Cool - 10-14C

Mild - 15-19C

Warm - 20-24C

Very Warm - 25-29C

Hot - 30-34C

Very Hot - 35C-39C

Extremely Hot - 40C+

Edited June 27, 2015 by Dan the Man

[SP1986]

The Greenland High is going to cause lots of headaches with regard to the short terms solution even, I suspect.. this is evident as close as 90 hours. The low pressure to the west does seem to be getting a better hold each GFS run, we see a continuation of this on the 6z, however this does not mean that we won't get a warm, sunny period of weather, just that it may not be quite as hot as originally modelled, and perhaps a little bit more unsettled, perhaps. Still warm though even in that potential scenario.