Model Output Discussion - 30/6/2014 Onwards - Covering July.

[draztik]

This is what I am reckoning will happen aswell, which in theory should give us another boost of warmth and thundery weather again . 

 

ECM showing high pressure trying to build behind this aswell 

 

Day 11 ecm ens / msl mean

 

if we must look post day 10... money is better placed with the ens than the op.

Edited July 24, 2014 by draztik

[knocker]

Not a great change with the GFs and ECM ens today with perhaps the GFS being more bullish with the trough.

Edited July 24, 2014 by knocker

[johnholmes]

Using the 500mb anomaly charts as a guide then looking at the 12z synoptic outputs

 

The 500mb charts, especially NOAA 6-10 and the 8-14 suggest a definite cool down with a trough over the UK in the 6-15 day time scales, probably beginning about 4 days from now. This tends to support the 12z GFS and ECMWF ideas today with both showing an  upper trough in the vicinity of the UK. Both suggesting 850mb temperatures of below 10C, possibly not far from 5C.

Compare this to the 12z actual 850mb temperature chart?

 

I would definitely go for a cool down and also for it to become more unsettled with time in the 4-15 day time scale.

What happens beyond then I do not pretend to know.

 

charts for comparisons

850mb chart 12z today

.http://www.netweather.tv/index.cgi?action=nwdc;sess=

 

NOAA 6-15 day 500mb anomaly output this evening

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

00z ECMWF-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

and the 12z which for some reason has all the data for both models which the 00z quite often does not

http://mp1.met.psu.edu/~fxg1/ECMWF_12z/hgtcomp.html

[SteveB]

Morning all,

 

Well there looks like a North/South divide next week according to the GFS, with some rain & showers for the North, patchy showers for the South.

 

Temps in mid-high teens from Mid Wales north, low-mid twenties to the South of that, but the temps do drop a little on the coasts from time to time.

 

 

 

 

Not a bad week next week, just not as good as the week we've just had.

 

FI turns warm again.

Edited July 25, 2014 by SteveB

[mushymanrob]

Using the 500mb anomaly charts as a guide then looking at the 12z synoptic outputs

 

The 500mb charts, especially NOAA 6-10 and the 8-14 suggest a definite cool down with a trough over the UK in the 6-15 day time scales, probably beginning about 4 days from now. This tends to support the 12z GFS and ECMWF ideas today with both showing an  upper trough in the vicinity of the UK. Both suggesting 850mb temperatures of below 10C, possibly not far from 5C.

Compare this to the 12z actual 850mb temperature chart?

 

I would definitely go for a cool down and also for it to become more unsettled with time in the 4-15 day time scale.

What happens beyond then I do not pretend to know.

 

charts for comparisons

850mb chart 12z today

.http://www.netweather.tv/index.cgi?action=nwdc;sess=

 

NOAA 6-15 day 500mb anomaly output this evening

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

00z ECMWF-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

and the 12z which for some reason has all the data for both models which the 00z quite often does not

http://mp1.met.psu.edu/~fxg1/ECMWF_12z/hgtcomp.html

 

bib... but with your experience, couldnt you make an educated guess? it might turn out to be inaccurate but havnt you a general idea of whats most likely?

 

yes, the noaa's this morning dont make good viewing for heat lovers. although the gfs 00z does bring back the scandinavian high albeit in fi and without support. the scandinavian high has been a regular feature this year and has brought us this current heat (albeit via an azores ridge being absorbed).  will it return, or will the atlantic now dominate?

[Captain Shortwave]

The ECM is really struggling to break the warm air over the south down, as it has over the last couple of runs. This would mean a warm week for the south with very little rainfall bar a few showers. The north looks cooler and more unsettled.

 

With the 8C isotherm over the south, temperatures should easily hit around 25C which isn't too bad and still above average. The ECMis never cool and never really below average in the south even to day 10.

^The GFS ensembles do show an improvement in conditions during the latter stages, question is will it materialise.

Edited July 25, 2014 by Captain shortwave

[carinthian]

Morning, still think there will be some complications over the near continent as early as Sunday Evening/ into Monday. The colder upper flow on most models wants to sweep away southwards the higher thickness values over mainland Europe rather quickly. I think ECM model develops more energy within the heat source in its projected charts.

[Summer Sun]

The main difference next week will be the change in wind direction temperatures will be lower next week yes but they are only likely to fall back to around average possibly still slightly above average for some southern and south western parts. Although nowhere is immune to rain / showers the south should still see some reasonable amounts of dry, bright and more comfortably temperatures

 

Tuesday and Wednesday don't look bad with just scattered showers and temperatures in the low to mid 20's especially on Tuesday

 

 

Thursday looks more unsettled for some with pressure lower to our east the south west looks the best place for drier weather

 

 

Tuesday has +8 850's for all

 

 

No 850's available for Wednesday, by Thursday the air becomes fresher though the far south clings onto the warmth

 

[Man With Beard]

Two very different pictures for next weekend!

GEM is about as autumnal as you can get - ECM is half-decent, perhaps with a weak front / a few showers, warmish in the south.

 

As John Holmes has mentioned, this NOAA chart does suggest low pressure close by for the beginning of August:

But this does not automatically exclude any summery weather. I think I mentioned a month ago - when another upper trough was predicted to be close to the UK - if a low develops in the Atlantic but does not push through the UK, we keep a SW flow with potentially above average temperatures and progressively drier as one heads SE. One that occasion I was proved correct and the SE got into the 80sF.

 

This time we do not have strong heights to the east though - so while I don't rule the same evolution out, the chances of this happening again are less this time - with the chart above, we could easily see low pressure moving slowly from west to east.

 

Recent GFS op and ens runs go for strong height rises once again after D10 - so a little unsettled patch next weekend could end up a blip rather than a pattern change - but the ECM ens don't seem in a hurry to return strong heights, judging by the D10 mean chart this morning, so we're several days away from being able to call this. T

Edited July 25, 2014 by rjbw

[Polar Maritime]

I have just had to delete a post, Can we please stick to Model Output discussion in here.

Many Thanks. PM

[johnholmes]

Two very different pictures for next weekend!

GEM is about as autumnal as you can get - ECM is half-decent, perhaps with a weak front / a few showers, warmish in the south.

 

As John Holmes has mentioned, this NOAA chart does suggest low pressure close by for the beginning of August:

But this does not automatically exclude any summery weather. I think I mentioned a month ago - when another upper trough was predicted to be close to the UK - if a low develops in the Atlantic but does not push through the UK, we keep a SW flow with potentially above average temperatures and progressively drier as one heads SE. One that occasion I was proved correct and the SE got into the 80sF.

 

This time we do not have strong heights to the east though - so while I don't rule the same evolution out, the chances of this happening again are less this time - with the chart above, we could easily see low pressure moving slowly from west to east.

 

Recent GFS op and ens runs go for strong height rises once again after D10 - so a little unsettled patch next weekend could end up a blip rather than a pattern change - but the ECM ens don't seem in a hurry to return strong heights, judging by the D10 mean chart this morning, so we're several days away from being able to call this. T

 

 

Indeed, using these charts the position of the upper troughs and ridges is vital to the type of weather and temperature levels at the surface.

As with ANY model do NOT take one run but watch for trends. The trend, since I got back from holiday, so  4-5 days data, shows quite definitely that the weather type is showing more towards unsettled rather than settled. That is not to discount warmth or several days of decent weather for one part or other of the country.

A useful tool for sure but one that needs a lot of practice using them and being prepared to accept you get it wrong at times. I have data on the 3 I use for over 3 years on my pc and it shows a 70% plus rate for getting the overall pattern correct 6-15 days ahead, but it is also littered with instances where the guidance was less than good. All part of meteorology. good fun but don't get too uptight when it goes wrong and be ready to admit it.

[knocker]

The GFS and ECM are still singing the same song with the trough bang over the UK although the GFS is again more bullish. Neither seem in any rush to build up heights significantly although as the upper trough weakens the the GFS does have an encroachment of the Azores ridge by mid week but that's away down the road. In the meantime a tad unsettled with average or below temps.

 

[DTHFCJ]

The GFS and ECM are still singing the same song with the trough bang over the UK although the GFS is again more bullish. Neither seem in any rush to build up heights significantly although as the upper trough weakens the the GFS does have an encroachment of the Azores ridge by mid week but that's away down the road. In the meantime a tad unsettled with average or below temps.

Agree with you Knocker,as do these....

 

http://www.wetterzentrale.de/pics/MT8_London_ens.png

 

 

http://www.wetterzentrale.de/pics/MT2_London_ens.png

 

looks like a fall of pressure but then an upward trend towards the later part the run

 

i said to my wife back in may we wont get a july like last year..tbh its not been that far off here,we have done very well and that includes june just need a better august than previous years and for this part of the world itl be the best summer ive known since i had hair

[Frosty.]

The Ecm 00z ensemble mean shows high pressure pulling westwards into mid atlantic as time goes on although it does leave a weak ridge across most areas until well into next week but we will have to look more towards the northwest for our weather as lowering heights begin to slowly gain the upper hand, initially across the north but then more widely by the end of next week as a trough slowly slides southeastwards from iceland. The current very warm conditions will slowly moderate but southern england will remain on the warm side throughout with low / mid 20's celsius at worst eventually, at least for the southeast corner, closer to high teens to low 20's c (around 70F) further north so although it will cool down, it will never be worse than pleasantly warm as there is still expected to be a fair amount of sunshine but as pressure leaks away, there will be an increasing risk of showers becoming widespread across the uk, many of these being heavy and thundery, and with light winds, the showers would be slow moving with strong variable gusts associated with any storms. It still looks like decent summer weather, no sign of any cool, windy atlantic weather on the horizon which is good news for those (including me) who are enjoying this pretty good summer..CHEERS

[William of Walworth]

Blatant hopecasting here, and generalising too, but on previous summer occasions that I'm sure many on here will remember, trough influence has weakened somewhat/stayed further North the nearer to zero hours you get, with HP influence SOMETIMES not weakening as much as expected, or even remaining more persistant than some models predict. Of course the reverse happens too, but nothing's nailed on for next weekend yet.

Edited July 25, 2014 by William of Walworth

[mushymanrob]

Blatant hopecasting here, and generalising too, but on previous summer occasions that I'm sure many on here will remember, trough influence has weakened somewhat/stayed further North the nearer to zero hours you get, with HP influence SOMETIMES not weakening as much as expected, or even remaining more persistant than some models predict. Of course the reverse happens too, but nothing's nailed on for next weekend yet.

 

well thats true that so far expected atlantic incursions have failed to be as potent as sometimes modelled, especially by the gfs. but previously the nomaly charts didnt support such potency...this time they do...ok more runs needed to be more certain, but some sort of atlantic driven regime does look likely. mind you, thats not to suggest itll be autumnal and stormy, its looking around average at worst.

[terrier]

Well the deadly silence says it on in here tonight. All models now agreeing on a break down to cool unsettled weather next week. With very little signs out into fi of a rebuild of the high pressure. Unsettled sums it up tonight for the foreseeable future.

[Frosty.]

Tonight's GEFS 12z mean is looking very good towards the early / mid august period with the azores and scandi anticyclones linking up again, this happened recently and brought heatwave conditions to most of the uk and a repeat would be on the cards based on how this run ends..so, another burst of high summer weather could follow the more unsettled, less warm phase which is likely to slowly take control across most of the uk from the northwest by later next week, the most unsettled and coolest weather being generally reserved for the northwestern half of the uk, the driest, brightest and warmest spells for the south & east with temperatures into the low to mid 70's F...but then another nationwide fine and very warm / hot spell could evolve as we go further into august..fingers crossed

[Stormyking]

A change looks a certain now by the looks of it, but I still dont think it will last long though.

 

This though could make things quite warm and humid with some thundery showers in places, before a cool down arrives after this!

 

Not overally cool from this, would still bring temps of around 22/23'c in places

 

 

ECM almost on the same wavelength too 

 

[Summer Sun]

ECM shows things turning more unsettled as we progress through next week with all areas becoming fresher than of late though we should still make it into the low 20's for the south and high teens further north

 

Edited July 25, 2014 by Summer Sun

[Polar Maritime]

The Models are now getting a grips of the up-coming unsettled cooler spell, As I said the other day, The GFS has done very well at picking up this signal in its extended outlook for the turn of the Month. It will be very interesting watching the Models over the coming days on how stubborn this pattern will be.

 

 

Edited July 25, 2014 by Polar Maritime

[johnholmes]

Blatant hopecasting here, and generalising too, but on previous summer occasions that I'm sure many on here will remember, trough influence has weakened somewhat/stayed further North the nearer to zero hours you get, with HP influence SOMETIMES not weakening as much as expected, or even remaining more persistant than some models predict. Of course the reverse happens too, but nothing's nailed on for next weekend yet.

 

William, the broad scale pattern is decided by the upper air pattern. This has for 3 if not 4 days now suggested less settled than for some time.

Take a look at the Extra 500mb chart or its 850 mb for the UK in this case; check that GFS/Extra agree with the upper pattern being predicted by the anomaly charts. If they agree, not necessarily totally, then you can start to take GFS/Extra charts out to 240h as a reasonable idea of what to expect at ground level.

Obviously it does not always work but whatever season if gives a more reliable and less constantly switching idea of what is most likely-honest!

[IDO]

Yes GEFS have been very consistent picking up this likely change to a lower pressure regime. Both JMA and the Chinese have also picked up this signal. Latest from the JMA & Chinese:

 

 

 

The JMA suggests that pressure recovers from week 3 and 4, though at the moment an anomaly just above average. The CFS for the whole of August also suggests a better second half of August:

 

 

So for the next week or two London returning to closer to average uppers: 

 

I for one will appreciate a fresher outlook for a while, maybe before a warmer end to Summer.

[Summer Sun]

This evening's ECM ens pointing towards a more unsettled opening to August

 

 

The 850's are around +7 widely for England and Wales with parts of the far south seeing +8's

 

[tinybill]

evening  all looking at  the  models looks like our  dry  weather gone  for a while  even looking  in to fantasy world  its looking wet at the  moment

 

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6