Model Output Discussion 18th Nov.2013-12z onwards.

[Gavin Hannah]

The PV is having a tough time of it lately. The charts posted by S.S above resemble something more akin to mushed up jelly beans lol.

[BLAST FROM THE PAST]

The pattern we've had and look like getting is displaying a jet far more meridonal/loopy than one would expect with such a PV and strat signal.  Serious arctic air invading way south in the US, and if day 8-10 comes off here which models are currently showing....that would be quite a bonus.  Will it be that amplified though???

Although nothing really to write home about yet pM air IMO is much more palatable than tM air which one could easily expect with PV and strat being so cold....but we're out of the 90s and early 00s....

 

I would post an image but for some reason I cannot do that so I'll try and explain my thoughts.  Crucial period I'm looking at for the amplification to verify or not is around t160 mark.  HP moves across UK and another is in mid Atlantic.  There is a little trough in between which acts to flatten the HP SE wards and the LP to our NNW then moves SE ward and the HP in Atlantic ridges north.  If the HP over us doesn't sink/flatten SE'ward the amplification won't occur and we'll be in W'ly flow and not NW'ly to N'ly.  It is all FI but there is support from numerous models for day 8-10 with similar outcome presently shown.

 

BFTP

Edited November 26, 2013 by BLAST FROM THE PAST

[bluearmy]

 

I remember captain shortwave saying at the weekend

"I do wonder whether the models will toy with developing a deep Atlantic trough in week 2 which consequently would push the Azores/Atlantic high north east through the UK"

....and this did have support from the Korean Met, which had this evolution by mid december

Now, this has support from the ext ecm ensembles, which is showing an Atlantic trough, with heights pushing NE by day 15

 

looking at naefs, i wouldnt discount it. so many options on the table once the trough pushes through and drops south. (none of them look to be higher heights in the greenland locale)

[Yarmy]

Once again the GFS gives us something tantaslingly close to special:

 

 

But then the high just drifts east across the Atlantic. Not quite enough oomph (technical term) in the ridging on both sides of the pole to join together in glorious matrimony over Greenland.

[Catacol]

Iv tried to find this but can't. Can you give me a link please

 

http://www.metoffice.gov.uk/publicsector/contingency-planners

[nick sussex]

No change today with the overall model trend out to day 10, high pressure displacing further to the west and nw.

Unfortunately theres no sign of any prolonged pressure rise over Greenland so this has to lower expectations to what can be achieved given no HLB.

A chance of a northerly with some snow but even this is reliant on the upstream pattern remaining sufficiently amplified at the key timeframe.

Theres little to suggest a major pattern change within 240hrs or what many would like to see which is ice days and a prolonged colder spell.

In the context of some recent cold spells people might be a little underwhelmed but things could be alot worse so its neither bad or great. If we can squeeze a few northerly topplers until the NH pattern becomes more favourable then thats really okay IMO.

[Tim Bland]

Maybe I'm viewing the output incorrectly but I see the potential of another January 1984 developing from around the first week of December, maybe not the longevity of that spell which around these parts gave us over two weeks of cold and snow. 

 

Im afraid your either viewing it incorrectly or through rose tinted glasses. I can't see any evidence for a sustained cold spell at the moment. I think a repeating pattern including occasional Northerly topplers is the best we can expect in the next few weeks.

[Summer Sun]

Iv tried to find this but can't. Can you give me a link please

 

The latest one for all of winter can be found at the link below, they are updated monthly

 

http://forum.netweather.tv/topic/75389-met-office-contingency-planners-forecasts/?p=2845038

[Catacol]

 

I noticed this the other day. May just be noise as it's difficult to say why a model that is worse at T144 would be better at T240. However, I suppose if the GFS takes better account of snow cover/albedo/surface temps/whatever as the run evolves you could see how it might be better later on.

 

Interesting. I think that some of us who have scrutinised charts for years would say that observationally the GFS has a habit of picking up trends at long range. At the start of november 3 GFS runs in a row picked up the high pressure that got everyone excited this month and it did so at 300h plus. So long range GFS is always worth a look just in case a trend starts to develop from the op runs. The big problem I guess is that joe public doesnt get access to ECM out past 240, so hard to compare what ECM would be like at the 300h range in picking up trends. But certainly I rank ECM well above GFS for its accuracy at 72 - 168 but out at 192 and beyond I tend to start looking at GFS once again because of its habit of being a trend setter.

 

Backs up the data, or vice versa, I guess.

Edited November 26, 2013 by Catacol_Highlander

[UV-RAY]

Im afraid your either viewing it incorrectly or through rose tinted glasses. I can't see any evidence for a sustained cold spell at the moment. I think a repeating pattern including occasional Northerly topplers is the best we can expect in the next few weeks.

Read it again as I didn't suggest a sustained cold spell, merely a watered down version of January 84.

[IDO]

This end of week toppler is flattening out as we hit the hi-res. Latest GFS 06z: 

 

  A 24 hour drop in uppers in the south (London).

 

This morning's ECM extended temp. mean tells us nothing due to the split amongst its ens. The cold ones suggest High Pressure close to the UK:  That is, the GFS FI current output.

 

The GFS T240 06z mean:  Seemingly downplaying the D10 2-3 day toppler.

 

The control highlights this: 

 

I suspect the models will meander about till the projected amplification is resolved.

Edited November 26, 2013 by i'm dreaming of...

[Captain Shortwave]

No change today with the overall model trend out to day 10, high pressure displacing further to the west and nw.Unfortunately theres no sign of any prolonged pressure rise over Greenland so this has to lower expectations to what can be achieved given no HLB.A chance of a northerly with some snow but even this is reliant on the upstream pattern remaining sufficiently amplified at the key timeframe.Theres little to suggest a major pattern change within 240hrs or what many would like to see which is ice days and a prolonged colder spell.In the context of some recent cold spells people might be a little underwhelmed but things could be alot worse so its neither bad or great. If we can squeeze a few northerly topplers until the NH pattern becomes more favourable then thats really okay IMO.

I think we will need to wait to beyond Christmas before we realistically have a chance of something special developing. There is good support for the Aleutian ridge to continue to plug away at the polar vortex throughout the next month or so, so it might just be a matter of patience. I expect we will see some signals for blocking developing after new year probably. Before then there is no reason to think that we won't get any opportunity for snow. Most likely the high to tend to drift around close to the UK and most likely west of the UK throughout the month. Interestingly if this were to be the case, then my prediction for December  I made a couple of months back might be close to being spot on.

Edited November 26, 2013 by Captain shortwave

[Summer Sun]

GFS temperature charts for the next 8 days continue to show most places becoming less cold

 

8 day anomaly

 

 

Expected temperatures

 

 

Normal temperatures for the time of year

 

[Joe Levy]

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=189&y=177 (South-West England)

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=244&y=6 (Northern England)

Not quite as cold ens as the 0z, but fluctuations are to be expected as the models grapple with varying degrees of amplification. It is also worth bearing in mind that all the GEFS sets were cold yesterday, so this could be an anomaly, however it's probably just within the natural variation that the models are showing at the moment.

[Newberryone]

Overall nothing very special about these charts in terms of cold but at least when one compares the opening frames with the last, subtle differences certainly emerge. Trending a lot cooler as we progress through next week although the Azores high never too far from view as highlighted on Dec 6th 

[EML Network]

The 06z control run has to be the least inspiring run in the entire history of GFS'.

 

it takes 17 days to go from this...

 

 

to this... (Someone wake me up in 2k14  )

 

Edited November 26, 2013 by EML Network

[IDO]

Pertaining to the FWIW:

 

  MattHugo81
Some support from the CFSv2 but latest EC32 back on the high pressure trail, with a particularly settled/high pressure outlook well into Dec
26/11/2013 11:42

 

___________________

 

Certainly ties in with the hints coming from the GFS.

Edited November 26, 2013 by i'm dreaming of...

[legritter]

Yes i tend to use Gfs as a trend setter ,but of course at the 10/15 day range its usually a different synoptic situation every run .on the face of it in this moment in time looking at current models and Data it looks like a cold plunge Friday and Saturday then high pressure again and later next week something with a bit more meat on the bones ,and very tantalising but at 9/10 days many eventual outcomes are yet possible .

[johnholmes]

Here goes:http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

 

thanks for that I will book mark the link

[Mucka]

Well GFS 06z was complete guff but then it often is. I certainly wouldn't want the cold signal to look so suppressed in the 12z (actually pretty much wiped out)

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=255&y=90

 

No doubt, for whatever reason the 06z run is almost always the flattest and therefore mildest of the 4 daily runs where there is some potential blocking around.

 

ECM 00z hardly encouraging either with a brief toppler programmed for day 11. At least it shows up as comfortably one of the milder solutions among its ensembles and chances are it will at least look a little better this evening. (no guarantee though).

 

 

It is still early days as the much anticipated cold snap/spell is just coming into view and at this distance it is hard to see if it is a snowman or scarecrow. (such whimsy! )

 

The GFS 00z was largely encouraging but the est of the output including ensembles are quite mixed.

As others have mentioned we may do well to limit our expectations unless we see some much more encouraging signs for some HLB to take hold over the next two or three days.

Currently if we get anything more than a 1 day toppler it is still the Northwest that will be best placed to benefit. Personally I would bite your hand off if offered the GFS 00z Op run right now rather than gamble on the rather slim chance of something better.

 

Cautiously optimistic of at least seeing some snow falling here in the NW between the 5th and 9th of December, beyond that 

[Mark Neal.]

It seems like there is no sign of any HLB across much of the N Hemisphere, with the high over us staying closeby for much of model runs taking us into December. There seems a sound possibility that around 7-10 day range we will see some pressure on the vortex around Greenland and could see a push Eastward with signs of some kind of higher heights pushing closeby and core low heights of vortex heading further east. We then could see a push of colder air again southwards through a toppler but we will have to wait for further model runs and closer to the dates to see if this is likely to occur.

It does seem that any northerly toppler would be a brief affair and looks like we are trying to squeeze the best out of a poor outlook HLB wise, so not overley disheartning if you are looking for colder and wintry synoptics, though nothing substantial showing as yet! Plenty of winter to go, it ain't started yet

Edited November 26, 2013 by Mark N

[Summer Sun]

The 06z control run has to be the least inspiring run in the entire history of GFS'.

 

it takes 17 days to go from this...

 

 

to this... (Someone wake me up in 2k14  )

 

 

Its not quite high pressure all the way

 

[MR EXTREMES]

been watching the drama unfold again as you can see last nights delights where replaced by yet another deflated set of runs not a lot going to happen and its looking likely that up until mid December the general theme will be uneventful its getting rather boring to be honest even above average and gales would at least be a little more exciting.

 

but the models are even not sure on this.

 

I think jan will be a better month as I don't see no blocking to our ne or our nw until the vortex changes I think the drama will continue and emotional rollercoaster it certainly is.

[UV-RAY]

been watching the drama unfold again as you can see last nights delights where replaced by yet another deflated set of runs not a lot going to happen and its looking likely that up until mid December the general theme will be uneventful its getting rather boring to be honest even above average and gales would at least be a little more exciting.

 

but the models are even not sure on this.

 

I think jan will be a better month as I don't see no blocking to our ne or our nw until the vortex changes I think the drama will continue and emotional rollercoaster it certainly is.

Lets hope January delivers for you then as I fear for your sanity otherwise.

[Richie V]

I have never seen such a bland set of charts in the history of the gfs. I am going to make a strong point of viewing NO model output in the next 10 days. Hopefully more intrest by then.