Model Output Discussion 1200 hrs 15/11/14

[Cloud 10]

But what if, as is often the case, winds do not blow across the North Sea? I see nothing - as yet - to suggest an imminent Snowmageddon...

 

How about now? 

 

[Yarmy]

Hilarious how it goes so wrong....

and then goes so right 

 

Lets see what tomorrows model output brings

Great example though of how it's possible for the UK to be cold even with a +NAO and neutral/+AO. A rare beast, I'd imagine. It's a Lego high (a Scandinavian block :-) ).

[Snowy L]

Some crazily good agreement between the GFS op GFS Para and ECM tonight at pretty much the exact same timeframes. All 3 going for the Atlantic ridge pushing North towards Iceland between the T192-T240 time. Normally I would dismiss this, but this is 3 models going for pretty much the exact same thing at pretty much the exact same time.

[seabreeze86]

The GFS (p) has gone mental in La La land but still is special to look at.

 

http://modeles.meteociel.fr/modeles/gfsp/runs/2014111518/gfs-0-324.png?18

 

 

Probably gone by the morning but im going to buy a snow shovel on the off chance its right

[A.J]

Well looky looky hellooo winter!!

 

Hat's off to Steve "mystic"Murr !!. Even if this does'nt come off,what a call predicting this chart from the charts that were showing day's ago. 

not forgetting the other posters who've made similar predictions, it's not a one horse show 

bare in mind though, that if these synoptics do not transpire, then it's not a good call, if you think about......just saying 

 

Still, an 'interesting' pub run to be sure, with the parallel run's booked the lock in I think! that's a solid block with LP's diving under into the mediterranean basin reinforcing the easterly flow......let's hope that tomorrow's output show some consistency with today's, at least then we have a trend to go on

[knocker]

Intriguing difference between the GFS and the 1534

 

 

[Nick F]

Broad similarties between 12z ECM and 18z GFS looking at the upper pattern just before the jigsaw pieces fall into place for a northerly, then northeasterly and eventually easterly on GFS, though the peices fall into place post t+192.  But it does increase the excitment levels when both the ECM, GFS and GFS P are all singing from the same hymn sheet!

 

The trigger initially appears to be a shortwave 500mb trough coming out of NE Canada circa t+168, which then sharpens deeply thereafter as it enters the far NW Atlantic/southern tip of Greenland - with an intense surface low aiding the amplification of a downstream ridge towards Iceland. The flow then becomes increasingly convoluted over NE Altantic and northern Europe, with the ridge amplifying north into the GIN corridor, whilst further east a trough digs south into central/eastern Europe, GFS goes on to show the flow further buckling to allow a Scandi high. ECM doesn't get that far or so buckled, with a northerly. But often the northerly can be a precursor to a northeasterly or easterly as the cold pool sinks south into central Europe and heights build in across Scandi - as per GFS.

 

Even if the jigsaw pieces don't quite fall into place first time if the flow buckles over Europe in response to the trough digging down across the NW Atlantic, further waves of warm tropospheric air pushing up towards the arctic between Greenland and Scandi will help put further pressure on the Polar Vortex and help with wintry propsects for the winter to come.

Edited November 15, 2014 by Nick F

[knocker]

Broad similarties between 12z ECM and 18z GFS looking at the upper pattern just before the jigsaw pieces fall into place for a northerly, then northeasterly and eventually easterly on GFS, though the peices fall into place post t+192.  But it does increase the excitment levels when both the ECM, GFS and GFS P are all singing from the same hymn sheet!

 

The trigger initially appears to be a shortwave 500mb trough coming out of NE Canada circa t+168, which then sharpens deeply thereafter as it enters the far NW Atlantic/southern tip of Greenland - with an intense surface low aiding the amplification of a downstream ridge towards Iceland. The flow then becomes increasingly convoluted over NE Altantic and northern Europe, with the ridge amplifying north into the GIN corridor, whilst further east a trough digs south into central/eastern Europe, GFS goes on to show the flow further buckling to allow a Scandi high. ECM doesn't get that far or so buckled, with a northerly. But often the northerly can be a precursor to a northeasterly or easterly as the cold pool sinks south into central Europe and heights build in across Scandi - as per GFS.

 

Even if the jigsaw pieces don't quite fall into place first time if the flow buckles over Europe in response to the trough digging down across the NW Atlantic, further waves of warm tropospheric air pushing up towards the arctic between Greenland and Scandi will help put further pressure on the Polar Vortex and help with wintry propsects for the winter to come.

 

Sorry Nick I'm lost here how are the ops GFS and the 1534 singing from the same hymn sheet at T240?

[Cleeve Hill]

El Niño is about to being moderate (according to Michael ventrice @mjventrice on Twitter). He seems to know his stuff.

There appears to be a lot of things about to happen which should change our fortunes if you are looking for something a bit colder.

[Jason M]

Control at day 10 looks consistent. Not as cold, but the basic pattern is the same.

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=240&mode=0&carte=0

It may well look different tomorrow but the signal is strong enough that it cant be just disregarded as a pub run special.

[Nick F]

Sorry Nick I'm lost here how are the ops GFS and the 1534 singing from the same hymn sheet at T240?

 

I'm lost with your question, the ops GFS and what?

[BlueHedgehog074]

Tonight's NOAA 500mb 8 to 14 Day Anomaly chart is quite consistent with what it was showing yesterday (mind you these charts don't tend to change much) - an area of lower than average heights to our West (blue dashed lines) with a dip in the 500mb flow (green line) suggesting the idea of an Atlantic trough in that area. It does show a stronger signal for higher than average heights to our East over Europe than compared to yesterday's chart, although both show a bump in the green line which would still suggest a ridge to our East/North-East.

 

Yesterday's NOAA anomaly chart

 

Today's NOAA anomaly chart

 

 

Both also show some higher than average heights extending towards the Pole area, although when looking at tonight's chart, the positive anomalies in that area aren't quite as strong in relation to the stronger positive anomalies to our East. However, if Lows out West align favourably against blocking to our East and North-East, then we could see continued warm air getting pumped up towards Eastern Greenland, which may help to keep the Vortex and its Low Pressure making machine away from the UK. It's probably fair to say that with the slight Westward shift of the higher than average heights to our East on tonight's chart, their's a seemingly small decrease in the Atlantic influence, and would increase the chances of the UK seeing mostly settled conditions. It also mirrors the idea of some of the operational charts showing blocking over, or to the East/North East, of the UK with a flow possible between the South-West or South-East. And maybe possibly East if the block can push itself further West at times. Also, with the troughing in the Atlantic looking stretched on the anomaly chart (especially with the way it's sandwiched in between those positive anomalies to our East and the weakish positive anomaly over the Eastern Northern American coast), then it suggest things looking quite amplified in that area and it perhaps wouldn't be infeasible to see some of those low heights drop underneath the block to the East. Another aspect that could help prop up the blocking high and perhaps get it to back further West. Although this is not certain, and I suppose as some have said earlier on, you would have to be careful that the Lows out West don't start piling over the top of the blocking High Pressure to the East of the UK as it could make it harder for the High Pressure to retrogress to our West or North-West.

 

One thing this chart doesn't show is higher than average heights to our North-West. So either charts like the ECMWF 12Z and the GFS 18Z Parallel are just overdoing the build-up of strong heights to our West and North-West, or that it's something that the NOAA anomaly chart may start picking up on in future. Charts, such as the 18Z GFS, does show that even if the blocking to the East fails to provide proper cold, then an amplified High to the West could be the answer the cold and snow fans need.

 

I think if future model runs start showing what the ECMWF and GFS show tonight with carrot-dangling outcomes, then I may start paying more attention to it. Otherwise, considering it was only a few days ago that charts were showing the Atlantic trying to bust back through, then I feel tempted to stick to the sort-of-middle-ground solution the NOAA shows with blocking mostly concentrated to the East/North-East. One aspect that seems apparent anyway, is that no powerful, zonal, Atlantic flow seems likely at present.

 

(PS: Secretly hope the GFS Parallel is onto something. Such an epic FI chart.  )

Edited November 15, 2014 by DiagonalRedLine

[Yarmy]

Knocker, what *is* the 1534? Honestly, I don't know. Is it an NCEP product?

[Nouska]

What are the odds of synoptics, rare as rocking horse pooh, turning up twice in four years on the exact same day?

 

 

 

Probably no chance of winning that bet but there is something in the current atmosphere state that must be conducive to such an extreme possibility - charts like these require a very special set of circumstances.

[knocker]

Knocker, what *is* the 1534? Honestly, I don't know. Is it an NCEP product?

 

Just the GFS(P)

[ukpaul]

I think the 1534 is what the Yanks are calling the GFS upgrade.

 

I asked earlier but it got swamped. Does anyone know the problems with the upgrade that have resulted in its takeover being postponed? 

[Yarmy]

Just the GFS(P)

Ah right, cheers.

[knocker]

I'm lost with your question, the ops GFS and what?

 

The GFS upgrade. These are the relevant charts.

[Yarmy]

I think the 1534 is what the Yanks are calling the GFS upgrade.

 

I asked earlier but it got swamped. Does anyone know the problems with the upgrade that have resulted in its takeover being postponed?

Someone posted yesterday that they found a few bugs (unsurprising in what I presume is still a Fortran codebase of several million lines) and would restart the parallel run when they were fixed.

[reef]

Just a polite reminder that if you find your post disappear then its probably in here:

 

https://forum.netweather.tv/topic/81281-model-banter-moans-and-ramps-autumnwinter-2014/

 

The aim is to keep this thread on-topic with a good level of discussion. Its especially important as the charts get interesting and the volume of posts increase.

 

Please think whether you're posting in the right thread. Generally if your post contains charts and relevant discussion its in here. If its a one-line comment, moan or ramp about the output its in the other thread.

[bluearmy]

Back to last night and knicker, nick was not referring to specific agreement on timings but agreement on broad long wave pattern in week 2. ie - all three models were getting to a similar place despite different evolutions to get there.

Anyway, to the here and now - anyone waking up and hoping that today's runs would bring a '2010 type countdown to cold' will be somewhat disappointed. (Remember that once the pattern was picked up by gfs fi, it counted down in the same fashion, run after run and pretty well across all the models without too much stress for us watching).

there are enough similarities in the evolutions this morning for us to retain encouragement that we could see winter before months end although pretty well all solutions remain feasible from warm sou'westers to frigid noreasters and everything Inbetween.

[tinybill]

morning all i know its a long way off in fantasy world if this comes off this place could melt down!!!

[Polar Maritime]

Back to last night and knicker, nick was not referring to specific agreement on timings but agreement on broad long wave pattern in week 2. ie - all three models were getting to a similar place despite different evolutions to get there.

Anyway, to the here and now - anyone waking up and hoping that today's runs would bring a '2010 type countdown to cold' will be somewhat disappointed. (Remember that once the pattern was picked up by gfs fi, it counted down in the same fashion, run after run and pretty well across all the models without too much stress for us watching).

there are enough similarities in the evolutions this morning for us to retain encouragement that we could see winter before months end although pretty well all solutions remain feasible from warm sou'westers to frigid noreasters and everything Inbetween.

 

Yes wise words there BA.. The GFSP continues on a very interesting theme this morning, Another variation of hopefully many more to come. Very interesting Model watching. One thing that stands out is that by the turn of the Month we could well be into a much colder pattern, Lot's to be resolved.

 

 

[Jason M]

Yep, BA is spot on. Looking through the output this morning as well as the ensemble runs nothing much has changed from last night in my view.

It doesn't matter that the eye candy has gone as this was expected. All that matters is that the general pattern remains the same. Things may well get more interesting over the next few days as the time periods in question move into high res range. It may well be that last nights cobra runs were a bit too quick. This would be no bad thing though as any delay simply means we move closer to December and hopefully easier access to cold 850s

I suspect zonal is off the table for the time being, but a deep southerly is certainly a realistic alternative to an easterly, so caution needed as always.

[IDO]

The growing trend for HP to take over is now a clear signal and the models have just got its locality, movement and orientation to resolve. As others have said don't rule anything in or out. The 12z ECM temps for London and this morning's GEFS show split clusters. Mild or cold and some in between:

 

 

 

GEM for instance continues with it's mild take on things:  

 

Support for that in the GFS op: 

 

Looking at the GEFS at D11 about 50% still have the Atlantic more prevalent than a MLB so although heights over the UK for around week 2 looking a very strong synoptic, longevity is still fluid: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=264

 

All this talk of cold in November and we forget it is a very mild month, CET now +1.8c and by the end of the week, depending on the low cloud, that could be very close to the highest above CET month (+2.4) of the year.

 

Could take a few days to resolve.

Edited November 16, 2014 by i'm dreaming of...