Model Output Discussion 06Z, 13 Sep. 2013 ---->

[mushymanrob]

Who's worried about that and if we get a nice day or three? Anyway, I'd bank these uppers (albeit at 2am!). And look at that Siberia-bound cold.

 

 

because it might take a while to lift, and spoil the chances of a nice day or three.

[Yarmy]

because it might take a while to lift, and spoil the chances of a nice day or three.

 

With those uppers and clear skies, it would burn off in no time I'd have thought?

[I remember Atlantic 252]

because it might take a while to lift, and spoil the chances of a nice day or three.

 

but still a damn sight better than last year, that chart is the anniversary of Child of Nadine (Karin) absolutely horrendous for the north midlands

[Frosty.]

The Ecm 00z op run shows the cool and unsettled spell on it's last legs by wednesday on a nationwide level, by thursday the unsettled weather becomes restricted to the north with weak ridging pushing in from the southwest/south, this process continues with the south becoming sunnier and warmer as high pressure builds in and this fine weather gradually extends across more and more of the uk by the end of next week and into the following week with a warm and sunny spell, what a huge contrast to a few days ago when the ecm ops were showing 10 consecutive days of very cool unsettled weather, although the run ends with cooler unsettled weather returning from the northwest, at least most areas, and especially the south & east have another taste of summery weather for 2-3 days with temps into the low to mid 20's celsius, maybe 80F for the southeast for a day or two.

[Captain Shortwave]

trouble is mate, theres no support for it being more then short lived (as has been mentioned), the anom charts do appear to be shifting away from a northwesterly flow, but as things stand there no suggestion for a decent lengthy settled anticyclonic spell. even if we did get one it might deliver cool nights with fog..  i hope we do get more settled, but its not looking likely atm.

 

... cool? if 'cool' is mid teens then ill take that anyday! it could be worse. (referring to various posts which are trying to paint a more gloomy picture then what we are likely to get). yes temps are below average, but thats the nature of the season. yes its going to cool down... yes the chances of heat is becoming very remote.... so what!

To be honest there is little agreement with each other but the GFS is very bullish about something more substantial developing

 

Momentum is definitely with the GFS version of events, with the ECM slowly extending any settled spell and the UKMO completely backing the GFS solution at day 6, there is definite hope for something decent to end September with

Edited September 15, 2013 by Captain shortwave

[mushymanrob]

With those uppers and clear skies, it would burn off in no time I'd have thought?

 

....which is why i said 'might'...

 

atm its all conjecture, but im just not looking at high pressure and thinking 'sunny and warm', especially after the rain we are going to get.

 

To be honest there is little agreement with each other but the GFS is very bullish about something more substantial developing

 

Momentum is definitely with the GFS version of events, with the ECM slowly extending any settled spell and the UKMO completely backing the GFS solution at day 6, there is definite hope for something decent to end September with

 

true there is little agreement between the main 3 (johns law :lol: ) , but they do all suggest a similar theme, dont know if that counts to a degree or not. but what they dont show (atm)  is any chance of a  settled spell.

[No Balls Like Snow Balls]

Both the GFS and UKMO 00z look similar @ T96. ECM is different, so I would say that until all 3 models are showing the same then you cannot take anything past 4 days as gospel. ECM is the best performing model after all and quite often knows the correct way ahead.

 

 

 

 

Could possibly be  a halfway house between ECM and GFS. Either way which ever model ends up correct it doesn't look like temps are gonna rise into the very warm category at the moment. Will feel nice in the sun though and prob warm enough for just a T shirt during the day.

 

GFS 00z ensembles still only go for a very short warm up (3 days at most again) before temps fall away to slightly below average.

 

 

The people that crave warmth and HP all year round know that they have to take what they can this time of year, I think that is why there seems to be so much excitement about temps possibly reaching 20c (thats just around about average, ever so slightly above) for a few days next week. If this was in the summer though there would be toys out of prams as it clearly wasn't warm enough lol. Funny how desperation seems to take over the closer to winter we get. Will be the same for cold and snow fans once winter departs.

Edited September 15, 2013 by No balls like Snow Balls

[Captain Shortwave]

Both the GFS and UKMO 00z look similar @ T96. ECM is different, so I would say that until all 3 models are showing the same then you cannot take anything past 4 days as gospel. ECM is the best performing model after all and quite often knows the correct way ahead.

 

2013091500_096_GFS.gif

 

2013091500_096_UKM.gif

 

2013091500_096_ECM.gif

 

Could possibly be  a halfway house between ECM and GFS. Either way which ever model ends up correct it doesn't look like temps are gonna rise into the very warm category at the moment. Will feel nice in the sun though and prob warm enough for just a T shirt during the day.

 

GFS 00z ensembles still only go for a very short warm up (3 days at most again) before temps fall away to slightly below average.

 

graphe_ens4.php.gif

 

The people that crave warmth and HP all year round know that they have to take what they can this time of year, I think that is why there seems to be so much excitement about temps possibly reaching 20c (thats just around about average, ever so slightly above) for a few days next week. If this was in the summer though there would be toys out of prams as it clearly wasn't warm enough lol. Funny how desperation seems to take over the closer to winter we get. Will be the same for cold and snow fans once winter departs.

I'm pretty convinced that the maximum temperatures are being undercooked here, a southerly flow with uppers of 12C would surely yield temperatures higher than 20C, I decided to take a look at some model output from late September 2011, and well

 

The GFS had a maximum of 23/24C for the 1st October, the actual maximum was 29.9C

So hmm maybe issues this late in the season with predicted maximum temperatures.

I personally would say 25C is not out of the question by next Sunday/Monday.

The momentum is all one way at the moment and wouldn't be surprised if the ECM is dragged kicking and screaming to the GFS solution, the UKMO appears to have shifted that way. If we do get a reasonable spell of weather then full credit to the GFS here as it appears to at least got a decent foothold of the effects Humberto would have on our weather patterns in the coming days. ECM has been flapping more than Joe Hart in an England match 

[johnholmes]

Does the interaction of (the remains of) Humberto with the surrounding conditions drive the resultant weather pattern or is it the interaction of the surrounding conditions with Humberto which drives the resultant weather pattern? If that makes sense? I've never really paid much attention to the models outside proper autumn and winter months, but much is made of the uncertainty which ex-hurricanes can cause.

 

As always in meteorology it is hugely difficult to decide which is the most important. I think what can be said is that the injection of the huge amounts of moisture and energy which ex hurricanes bring to the cooler areas of the North Atlantic create major issues for any of the weather models.

 

I'm just about to do the T+144 'picture' as to what the two major models make of Humberto

Edited September 15, 2013 by johnholmes

[johnholmes]

To be honest there is little agreement with each other but the GFS is very bullish about something more substantial developing

 

Momentum is definitely with the GFS version of events, with the ECM slowly extending any settled spell and the UKMO completely backing the GFS solution at day 6, there is definite hope for something decent to end September with

once again caution is needed with how to intepret the anomaly charts. Additional caution when they, as illustrated show varying ideas on what is the most influential item, trough or ridge. It is one issue so compare it to the last 2-3 and include the NOAA version before trying to make head or tail of what they seem to be suggesting. The overall idea from the last week or so from them is that ridging is something that seems to ebb and flow as does the idea of the trough being the major player. This uncertainty is something that seems to happen each autumn and can last for quite some time in some years. The variability of the anomaly charts explains why the synoptic models are 'chopping and changing' even without the additional input from Humberto at the moment.

Edited September 15, 2013 by johnholmes

[Frosty.]

These are wonderful charts for late september from the Ecm 00z op run, hope it's right this time I can see the daily mail/express headlines already...september sizzler on the way

Edited September 15, 2013 by Frosty.

[johnholmes]

re my last post, after looking again at the NOAA output from last evening and the ECMWF-GFS this morning I make this comment

 

Taking the last 8-14 noaa and its main factors it is indeed best to stop trying to use these for predicting the upper air pattern for the time being

 

and the comments about each of the models below

 

Sun 15 September

Ec-gfs

Another change with ec this time showing the trough as the major player and gfs having the ridge!

Until all 3 settle down to a more coherent regular patternover a 3 day period I think they are best left and not used as any guidance for 6-15 days ahead!

 

Noaa

The major item on this chart is the +ve heights that continue to show nne of Svalbard, a minor –ve off nw uk and the actual trough from the main upper low off nw Alaska over Greenland towards Iceland and the uk

[johnholmes]

below is the pdf showing the latest situation, as of last evening, for T+144, remember this began with the T+192 outputs.

 

Humberto data on sat 14th for T.pdf

[Summer Sun]

Latest from Gibby

 

Good morning. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and the Fax Charts for today Sunday September 15th 2013.

 

The General Situation. All models show a Low to the NW of the British isles deepening and moving slowly East then SE down the North sea over the coming days to be in the vicinity of Germany by Thursday. Troughs will cross SE over the UK today with another feature crossing the South on Tuesday with more persistent rain in association with these while in between times squally showers are expected driven on by strong to gale NW winds especially in the North and West at first and the North and East later. By Thursday conditions will moderate over the UK but with a further spell of rain crossing East as a precursor to this before quieter and less unsettled weather extend across Southern and Eastern areas at the end of the week and through next weekend with some dry and bright weather to be found with some decent warmth and brightness by day but with the chance of mist and fog overnight towards the far South. The north and NW may well continue more changeable and breezy with some rain at times as Low pressure remains to the North or West.

 

The Fax Charts a complex Low pressure based pattern through the working week with troughs today giving rain before a strong NW flow takes over for several days. Wave depressions are shown to cross close to Southern England on Tuesday with a further set on Thursday with rain in a fresh Westerly breeze.

 

GFS then builds High pressure up from the SW across most areas next weekend with fine and warm conditions developing especially over the South as an Easterly drift feeds warm air off a warm continent. High pressure remains in charge then centred over Northern Britain with a lot of tranquil Autumn days with mellow warmth and sunny spells by day while the night could become very foggy at times, especially in the North. Late in the run the weather slowly deteriorates as Atlantic depressions gradually edge in from the West in freshening Southerly winds.

 

The Jet Stream shows the flow piling SE over the UK for much of this week before it ridges North to be positioned North of the UK in a weeks time in an undulating North and South moving pattern over the Atlantic.

 

UKMO today closes it's run with a slack zone of pressure across the UK next Saturday with a lot of dry and fair weather in average temperatures for most places. The far North and West of the UK do look as though they will come under the influence of a NE moving warm front through the day with thicker cloud and occasional light rain.

 

GEM tries to build High pressure up from the SW too next weekend but with less success and would only give Southernmost parts a drier and brighter interlude before an active Low and fronts bring rain and gales to the North which the remnants of spread South to all areas before the close of the run sees a north/South split weather pattern develop with the driest and brightest conditions likely across the South in a Westerly flow.

 

NAVGEM looks a lot like UKMO at the Day 6 point moving forward with a cold front moving slowly into the North and West from the Atlantic. A few dry and bright days seem likely across the South before cloud and rain move across the North and West late next weekend with strengthening SW breezes.

 

ECM today shows slower changes towards High pressure next weekend with less windy and changeable conditions to end the working week before a ridge of high pressure crosses the UK over the weekend from the West with a dry and bright spell for most before a SW wind freshens and brings rain in from the NW later in the weekend. the trend towards the end of the run returns unsettled weather to all as troughs swing NE delivering occasional rain and showers to all in average September temperatures.

 

The GFS Ensembles show an unsettled week before High pressure brings a drier spell to the South through next weekend when it will feel rather warmer before more changeable weather is favoured to return across most areas in average temperatures later in the run. The operational was a warm outlier as expected with such a long spell of anticyclonic weather shown.

 

In Summary there is a general pattern formulated between the models today of a wet and windy start to the period gradually moderating towards the end of the week as fronts become less and less active and eventually leave the South and East altogether next weekend to give a spell of tranquil early Autumn weather in these areas. The further North and NW one travels the chances of unsettled and at times wet weather increases though even here things look less Autumnal with regard to wind and rain than this week. Later on in the output it looks like High pressure will gradually loosen it's grip again with a traditional mix of Atlantic fronts bringing wind and rain alternating with drier and brighter interludes with showers though it looks though this will always be concentrated towards the North.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

[Frosty.]

The Ecm 00z ensemble mean is oozing potential for a significant warm up by the end of the week ahead as the azores anticyclone builds northeastwards, the southwest/northeast alignment is much better than the recent west/east and there is now potential for temperatures to soar into the mid to high 20's celsius for a time across southern britain and in particular, the southern half of england & wales followed by a thundery breakdown before it turns cooler and fresher but right at the end, there are signs that high pressure could be poised to build in again. In the meantime, it remains cool and unsettled until midweek but it's an improving picture with more in the way of sunshine and a gradual reduction in the winds, rain and showers as pressure begins to rise slowly from the west towards midweek, now although the PFJ pulls further north along with the cool/unsettled weather, there will still be fronts pushing across the uk so a few more spells of rain to get rid of before the influence of the higher pressure kicks in, but since there is growing model support for a fine and warm spell, these ecm charts look realistic in how the warmth and sunshine takes over although the northwest corner of the uk could struggle to settle down, at least it looks like becoming warmer and more humid across the whole of the uk by the end of the week and into the start of the following week, almost plume like conditions across the south/se for a time.

[Frosty.]

The GEFS 00z mean also shows a major warm up by the end of the week as high pressure takes control for a few days with temperatures of 25 celsius + with sunny days and a light southerly drift, pretty similar or even better than the Ecm 0z ens mean, it would be a nice bonus to have a few more very warm or hot days..even beyond that, the pressure pattern looks very sluggish with temperatures either average or a little above, sunny spells and mainly light winds, overnight fog and also the risk of a few heavy showers at times, pretty benign really with the PFJ well to the north of the BI again.

[Captain Shortwave]

I think the GFS has lost the plot on this run 

So a East Canadian, Atlantic, UK, Scandi, Russian high anyone.

[draztik]

The updated ecm control showing the UK staying under uppers of between 4-8 for the majority of its run this morning. Best chances of any warmer weather is confined to the South, which could see some days with uppers of between 8/10. In terms of settled/unsettled, there is a bias towards unsettled conditions ruling the roost, esp the further north you go.

as for the ecm ens showing signs of pushing temps towards the high 20's, im not seeing that. Its also not reflected in the BBC's 10 dayer, which shows a temp range of 15-21C for the SE next weekend. A lot of hope being injected into analysis this morning.

Edited September 15, 2013 by draztik

[Frosty.]

Phew what a scorcher...the GEFS 00z control really pumps up the heat, a very warm or hot anticyclonic spell for the time of year followed by a retrogressing pattern as a scandi trough sweeps a cold plunge south through norway.

[Newberryone]

I think that the underlying pattern is on a definitively cooler pattern now with the jet stream primed on its way south - and with the interesting height anomalies appearing to our north and north east which have been the focus of recent conversations in terms of longer term seasonal prognosis.

 

What is also interesting though in the much shorter term is that the unpredictable behaviour of Humberto could serve to align the jet stream back SW-NE, albeit temporarily, as it influences our weather patterns in this part of the Northern Hemisphere. Hence why todays output has shown the pendulum swing back at least some way towards the *possibilities* of a slightly quieter and less cool interlude of weather in the south at least late next week and into the weekend. However looking to stay more unsettled further north still.

 

With this tropical feature being as unpredictable as it is, and as they usually are at this time of year, we cannot rely on the modelling becoming less erratic however and any improvement *should it occur* further south is most likely temporary and regarded as a reflection of ridging extending from the atlantic for a time as a downstream response to Humberto taking control of the jet stream further north as it curves *somewhere* in the vicinity of the NE atlantic and *probably* to the north west of the UK. The EPS members show resonable support for this to happen based on the current suggestions by day 7

 

 

But taking any FI model output into account, there is a suspicion that the height anomalies to the NE are more likely to steer the jet stream angle back more NW-SE as Humberto is processed out of the system and a more widely cooler and more changeable scenario takes over again. Its worth bearing in mind that the modelling will  try and remove this blocking signal prematurely and thus it is not worth reading into both operational AND ensemble suggestion at this range.

 

Thereafter however, all that said, there is still the possibility of further seasonal tropical features  providing further interruptions to the cooler, mobile and unsettled theme. However, the prevailing theme from here on in will be one of late seasonal warmth steadily being eroded further and further back into southern europe, and becoming dependant on significant amplification of the jet stream ahead of any more major systems that enter the western and central atlantic that slow and *might* serve to pump up a ridge over the nearby continent or towards the Baltic and return some of the perimeters of this warmth northwards again for a time. But this is obviously based entirely on conjecture atm.

 

Clearly then, any prognosis from the end of next week is 'work in progress' and liable to revision and alteration in the days ahead . In the immediate term, the second half of this weekend with its first major low pressure salvo and then the majority of the coming week look distinctly autumnal, blustery and cool, with temperatures below average in the main and showers rattling through with a few longer spells of rain too.

Perhaps a few subtle changes in the long term forecast since this was posted but overall I feel the general content still applies. Transient ridges being the most likely outcome as opposed to blocking highs bringing temps into the mid-high 20's bracket as some members would have us believe. I can appreciate some might say they're only outlining what the models are currently showing but it's blatantly obvious their views are not unbiased unlike Tamara Road.

[Summer Sun]

Perhaps a few subtle changes in the long term forecast since this was posted but overall I feel the general content still applies. Transient ridges being the most likely outcome as opposed to blocking highs bringing temps into the mid-high 20's bracket as some members would have us believe. I can appreciate some might say they're only outlining what the models are currently showing but it's blatantly obvious their views are not unbiased unlike Tamara Road.

 

That is not fair one bit Tamara Road's views are not biased

[Captain Shortwave]

The metoffice update doesn't sound too bad either

 

UK Outlook for Friday 20 Sep 2013 to Sunday 29 Sep 2013:

After any overnight rain clears the far southeast on Friday, most areas will have a mainly fine day with some sunshine. The cloud may thicken through the afternoon in western areas with perhaps some rain later in the day. Probably becoming more unsettled next weekend in the northwest of the UK with showers or longer periods of rain, this possibly heavy in places. It will also become windy with a risk of gales on exposed coasts. Further south and east, although occasional showers are still possible, overall conditions will be much brighter and warmer. Thereafter, current signals suggest it will stay rather changeable with some rain at times, particularly further north. However, there are also indications of some longer brighter and warm periods developing, especially in the south and east.

UK Outlook for Monday 30 Sep 2013 to Monday 14 Oct 2013:

A rather changeable weather pattern is the most probable scenario during the first half of October with all areas of the country seeing some spells of rain or showers at times, but also some drier and brighter days in between. The best of these drier and brighter conditions are likely to be in the south and east. Temperatures will generally be near, or occasionally warm at times.

 

Sounds like the Metoffice are going for a north/south split which is a change from the past few days where unsettled conditions were set to prevail for all.

[Frosty.]

Transient ridges being the most likely outcome as opposed to blocking highs bringing temps into the mid-high 20's bracket as some members would have us believe. 

It's only what the models are showing, nobody is making this up, I have posted the charts and everyone can make up their own mind, I know there is the potential if the upstream pattern stays on this current course.

[Newberryone]

That is not fair one bit Tamara Road's views are not biased

Where did I say that Tamara Road's views were biased, in fact I believe it was the opposite. 

[Summer Sun]

Next weekend is looking more likely than not to see high pressure building this morning's UKMO is on board now

 

 

 

Now compare ECM to UKMO big differences in the position of the high

 

 

GFS is similar to UKMO only a day out

 

 

This develops into a mega big high stretching from America to Scandinavia via the UK