Model Output Discussion 1200 hrs 30/09/14

[Polar Maritime]

Can we please only discuss what the Model Output is showing in here. There is a Winter hopes/thoughts & bbc weather thread open for other musings.

 

Many Thanks, PM

Edited October 30, 2014 by Polar Maritime

[Yarmy]

Just to note that the GFS parallel is only just rolling out now, in case anyone was wondering why it hadn't updated from overnight. (Well I was )

 

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=code&mode=0&mode3h=0&runpara=1&carte=1

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY THURSDAY OCTOBER 30TH 2014.

 

NEXT UPDATE FRIDAY OCTOBER 31ST 08:00

 

THE CURRENT GENERAL SITUATION.A very mild SSW flow following a warm front North away from Northern Britain will persist through today and tomorrow.

 

MODELS-2 WEEK HEADLINE  Becoming cooler for all in more unsettled and sometimes windy weather with rain at times. Possibly drier in the South again later.

 

THE JET STREAM ENSEMBLE FORECAST The Jet Stream forecast from GFS shows a very complex outlook this morning basically hinging on an undulating flow across and to the North of the UK over the coming two weeks. After ebbing and flowing in strength too the flow eventally settles well North again late in the run between Scotland and Iceland.

 

GFS Today's operational run shows Low pressure gradually slipping SE down over the UK early next week and on down into the Meditteranean bringing a period of cooler and wetter conditions across the UK. A ridge then follows which as it moves SE too brings the UK back into a changeable Westerly pattern with rain at times chiefly in the North and West and temperatures becoming average or perhaps above again later with deep Low pressure well to the NW and High pressure not far from the South.

 

THE GFS ENSEMBLES.  The GFS Ensembles are supportive of it's operational in the first week but drift off towards more High pressure based weather over week 2 as it drifts from the UK across Europe leaving a ridge back West across the UK supporting dry and bright conditions with much mist and fog likely should it evolve as shown. A breakdown from the SW is hinted at Day 15.

 

UKMO. UKMO today shows Low pressure collapsing SE down the North Sea early next week with a rather chilly North flow with some rain being replaced by dry weather as a ridge folows down across the UK from the NW before midweek. Atlantic fronts behind the ridge look like they would affect the UK later in the week.

 

THE FAX CHARTS  The Fax Charts show warm sector conditions dominant again over the UK over the next 48 hours before a series of fronts moving in from the West dilute the warmth away gradually with rain and cooler winds at times for all by the early days of next week.

 

GEM  GEM today maintains the theme much more widely supported yesterday of a drift into deeply unsettled and chilly weather next week as two deep depressions cross the UK from the Atlantic with rain and gales at times for all mixed with brighter and cooler spells with showers, wintry on Northern hills. High pressure is then shown to ridge in by Day 10 and with cold air in place some hard frosts are possible.

NAVGEM NAVGEM shows the unsettled phase moving down from the NW at the weekend and start to next week a temporary phase as a strong ridge moving SE across Britain from the NW midweek brings more settled weather for a time before Atlantic westerly winds and rain move back in from the West by this time next week. 

 

ECM. ECM looks a lot like NAVGEM by this time next week with the well documented shift into cool and unsettled weather early in the week being interrupted by a drier period with some frost under a collapsing ridge midweek and a return to Atlantic Westerlies by the end of the week. With the Azores High making something of a shift towards Southern Britain and a Jet Stream moving back North mild air looks like making inroads across the UK once more most prolific as usual in the South and East.

THE ECM ENSEMBLES  The ECM Ensembles today show a rise in pressure across the UK from what the 10 Day mean Charts were showing yesterday and while the pattern of Low pressure to the NW and High to the South and SW is maintained with rain at times as a result it does reflect the trend of bringing our old friend the Azores High back into play later next week and pushing the Jet flow slowly back North which would mean only one thing and that is continuing mild conditions.

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There are still mixed messages from the models on the 7-14 day prospects shown between the outputs this morning though the effects from High pressure to the South building again somewhat later have strengthened.

 

MY THOUGHTS  Despite what appears to be a pattern change early next week as the Jet Stream finally dives South and cool North Atlantic winds together with Low pressure and rain all combine to give us all a feel of Autumn proper for several days it never looks like lasting all that long as by far the majority of output show a following ridge down across the UK at the middle of next week opening the door to the Jet Stream returning North and pressure to rebuild from the South to set up another spell of mild WSW winds around Low pressure to the NW and High to the SE or South. While it is unlikely to return as mild as it is currently it will limit the amounts of rain from Low pressure to the NW affecting parts of Southern Britain with a fair amount of dry and benign conditions as a result. GEM is one exception this morning which does show the deeply unsettled picture shown more widely across the UK next week and beyond while the GFS Ensembles go one step further with High pressure with a centre straddling the UK on it's way to Europe with fog at night becoming a hazard should it evolve. So all in all still a lot of confusion in the models going forward with a range of options on offer. What doesn't look likely though is anything harsh in weather terms be it from excess rain, wind, frost, ice or snow and my own feeling is that while there is a propensity to maintain High pressure near the Azores and mainland Europe and a Jet Stream profile maintaining it's preference towards Northern latitudes then the current generally mild theme is likely to persist with just varying degrees of mildness likely from one period to another and only very short cooler spells when frost and fog become briefly possible. Of course this is just my opinion and I may well be wrong but from a cold point of view all pointers currently indicated in the models don't support cold weather being anything more than transitory across the UK for the foreseeable future.

[MR EXTREMES]

850's dropping from +10 / 12 down to 0 / -2 or 3 would still be a welcome change from the persistent mild mush..winter is still a month away and this is still an evolving situation, the trend is turning colder.

indeed frosty and and so what if theres no cold snap still cooler from all models we are just into nov and the northern hemisphere is a different pattern.

 

as was suggested earlier we want lowing heights into europe ne heights to build or nw into greenland.

although last nov there was lots of possibles thrown out by the models which came close but failed.

 

remember we have just enjoyed lovely warmth but thats all set to change into next week and its still cold enough for wintry weather in the north on hills and mountains.

the models do this every year this is what is fascinating about model watching.

gem 

 

ecm

the difference is staggering......

 

gfs

 

gfs para 

they all look very much the same at this point and the gem being the odd one out.

worth noting though the gfs has been playing catch up to the ecm.

and the gem is now throwing a fit but was on the money with ecm at the start of the week.

Edited October 30, 2014 by emotional rollercoaster

[Polar Maritime]

The "new" GFS also shows a much cooler/unsettled N/W flow after the initial Northerly. The PV still disrupted with Heights over the Poles and no full on Zonal..

 

Edited October 30, 2014 by Polar Maritime

[No Balls Like Snow Balls]

A very small window for some snow over Scotland next week according to the latest all singing all dancing GFS 00Z run. It looks highly unlikely that snow will be seen anywhere else. But it will only be early November after all.

The latest ECM show's HP trying to move in again right at the end of the run, but according to the latest NOAA & ECM / GFS 500MB mean there is next to no chance of that happening with a continuation of LP driven and unsettled weather.

[Summer Sun]

In the much shorter term we could have some record breaking warmth in England and Wales for Halloween with temperatures widely in the high teens and we may see highs around 21c for some southern parts

 

 

Bonfire night looks more seasonal

 

[knocker]

The PV becoming more diffuse.

 

[shaky]

06z gfs and parallel run once again takes that low pressure further inland in the usa and therefore we got more of a stronger ridge in the Atlantic and maybe a more potent northerly!!models cant seem to make their mind up on that low!!!

[knocker]

Yes they have been struggling with it although they more or less in agreement on the 00z  The GFS was just a tad east of the ECM

Edited October 30, 2014 by knocker

[legritter]

Morning all ,as others have pointed out nothing too cold on the horizon but next week will become more mobile and more like autumn proper .But looking at 10 day charts today it would only need pressure to our south to fall more than currently projected and it could very well be rain rain and gales .it will also be interesting to see how the polar vortex starts to settle down and begins its period of growth .If mother nature balances the books to finish off the year we could see some interesting Model discussion and with plenty of prime time ahead Who knows whats around the next corner ,Early last December [Little did we know ]what was lurking around the corner ,bring it on STellas all round   , New GFS another tool in our armoury ,cheers gang .

[Frosty.]

One thing I will say about the Gfs 06z op run, for those enjoying the balmy 18-20c temperatures, make the most of it because the temps next week onwards look much closer to average, and with this being such a warm autumn so far, average will feel rather cold in comparison to what has gone before.

[Polar Maritime]

Just deleted a post, Madman is best kept out of the Model Thread.

Many Thanks, PM.

[IDO]

I know stratospheric warming is ongoing so I assume that this will mean the models are less reliable than usual. So the flip flopping may go on for a while. Certainly I see no clarity to the PV position(s) amongst the GEFS and run to run, and with the PV now one of the main drivers, then it is difficult to base forecasts on one suite from any model. The overall consensus from recent output is a slacker than usual westerly Atlantic flow bringing in LP systems from the NW/W. We may get temporary ridges and a bit of a PM flow on the back edge of an exiting LP system but nothing remotely indicating a pattern change to a winter synoptic (yet).

 

The 06z mean st D10:   D16: 

 

The JMA is just out and Week 2 ties in with the GEFS mean: 

 

Week 3-4 anomaly suggests a continuation of this theme with heights over Europe and lower pressure over the Atlantic: 

 

The uppers suggest an above average flow so nothing cold. So no real change from the long range models from last week; a period of more seasonal weather as the NH pattern establishes itself.

Edited October 30, 2014 by i'm dreaming of...

[IDO]

As it the life of model watching, the 7 day forecast of a northerly is at D6:

 

 

 

The Parallel is similar but the uppers are slightly cooler: 

 

In a stable upper flow it should be relatively dry inland with coastal showers. The weekend still showing two Atlantic fronts moving east. Again the first one should fizzle out the time it arrives in the SE. But Sunday's looks like pepping up as it stalls in the south. So not looking at all too bad for the next 7 days; fairly dry with average temps for the south. Next Thursday looks like heralding a warm front preceding the next Atlantic LP system, bringing a slight rise in temps.,,

 

...and not forgetting tomorrows very warm temps. Could exceed 21c in places.

Edited October 30, 2014 by i'm dreaming of...

[Mucka]

I think I would disregard the GFS 12z op for now t96+, looks like it has gone off on one with more of a closed low than a trough over the UK.

GFS Parallel and UKMO are not that far apart and both build heights through Scandi as expected 144.

Edited October 30, 2014 by Mucka

[Barry12]

Never mind the details, this is what we want to see happen. A propensisty to drop energy down through us into Europe via a NW - SE jet to our W. If this is a sign of things to come this winter, it's going to be a good one!

 

Rtavn1441.gif

 

UKMO at day 6

 

Is this the same thing?

[knocker]

I think I would disregard the GFS 12z op for now t96+, looks like it has gone off on one with more of a closed low than a trough over the UK.

GFS Parallel and UKMO are not that far apart and both build heights through Scandi as expected 144.

 

Am I looking at the same charts with the GFS as it looks like a transitory Azores ridge to me?

[SomeLikeItHot]

Am I looking at the same charts with the GFS as it looks like a transitory Azores ridge to me?

 

Current GFS is a transitory azores ridge, but the parrallel GFS (I think this is the upgrade being tested) is much more similar to the UKMO which is what he was saying. 

[Mucka]

Am I looking at the same charts with the GFS as it looks like a transitory Azores ridge to me?

 

It is but because the trough in central Europe is "propped up" on UKMO and GFS parallel which pushes heights into Scandinavia around 144+ as one would expect.

The GFS Op does not because of its modelling of the trough. See comparison charts GFS(p), UKMO, GFS op (note the angle of the jet)

 

 

 

Hence the difference in evidence by the 168 charts over Scandinavia (GFS (p), GFS op

 

Edited October 30, 2014 by Mucka

[IDO]

I think I would disregard the GFS 12z op for now t96+, looks like it has gone off on one with more of a closed low than a trough over the UK.

GFS Parallel and UKMO are not that far apart and both build heights through Scandi as expected 144.

 

 

Though GEM is a lot closer to GFS than to UKMO:

 

  

Edited October 30, 2014 by i'm dreaming of...

[Mucka]

Though GEM is a lot closer to GFS than to UKMO:

 

gem-0-120-2.png  gfs-0-120-4.png

 

It is. Where is your money though,  GEM and GFS or UKMO and GFS (p) 

 

I know no output should be disregarded completely but for now I think that solution is unlikely and expect ECM to be more in line with UKMO and GFS (p).

Edited October 30, 2014 by Mucka

[phil nw.]

A colder outlook for early next week continues to show on the 12s so far but nothing out of the ordinary by the looks.

We lose the current warmth by day 4 as the next low sweeps east across bringing a brief northerly and a drop in temperature for all

http://www.meteociel.fr/ukmo/runs/2014103012/UW120-21.GIF?30-17

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=120&mode=1&runpara=1

Thereafter it looks like we see temperatures closer to normal with the westerly flow bringing air sourced from the north Atlantic much of the time.

Those dark b!ues and purples(low heights)are becoming more extensive across the north which is the usual progression of the polar profile for November.They promise to dictate the Atlantic outlook for time being with a mobile setup. .

[Captain Shortwave]

It looks like we will potentially see the warmest Halloween on record. Temperatures going by the GFS

19/20C widely across England, perhaps a 21 or even 22C in any lucky spots. In fact we hit 20C in parts of London today so this week has been quite exceptional for the time of year.

 

Beyond that, no real sign on anything other than normal Autumn conditions with temperatures varying around the average mark.

Edited October 30, 2014 by Captain shortwave

[Duane S.]

UKMO at day 6

 

Is this the same thing?

 

If anything it is better as the jet is even more meridional