Model Output Discussion - 05/01/2016 18z onwards

[Midlands Ice Age]

6 minutes ago, radiohead said:

12Z GEM with a different take on things at T174

This is what would happen if the Arctic high and the Geenie high link up together.

It  certainly shows the route to cold.

It is possible.

 

Edited January 8, 2016 by Midlands Ice Age

[radiohead]

Just now, Earnest Easterly* said:

The UKMO has most definitely not drifted alongside GFS!!

It certainly moved towards the GFS solution at T96 and T120 in comparison to it's previous runs. It's a bit different to the GFS at T144 but it's almost like it's catching up on what the GFS showed 3 runs ago at this stage.

 

[Polar Maritime]

Sensible 'model output discussion' please, There is a moan/winter thread open, Ta

[coldcomfort]

18 minutes ago, karlos1983 said:

oh dear, backtrack central from the UKMO @120

Indeed....whatever way you try to slice it that UKMO 120 is a proper kick in the nads. The fact that it get's a bit more 'on message' again at 144 is neither here nor there imo, it's like dropping a tenner and finding a fiver.

 

 

Edited January 8, 2016 by coldcomfort

[slinky1989]

Does anyone have the model discussion threads from 2009/2010 archived?

 

I remember it being exactly like this with lots of upgrades until 5 daysish before the start of the cold, then lots of downgrades, then lots of confusion and mentions of shannon entropy, and then lots of upgrades again just as the main event started.

 

Would be interesting to compare then to now!

[Paul_1978]

12 minutes ago, Mucka said:

GFS was doomed to cool/cold snap by 120h as energy was already creeping through from the Atlantic due to the erosion of the ridge from Icelandic shortwave activity and the trough being too far West. Another fly in the ointment is that the models want to develop more shortwave energy on the Western flank at the base of the initial low just SW of Greenland. It is as though the weather Gods flicked a switch and have thrown every possible negative at our cold spell.

UKMO doesn't attack so much with the Icelandic shortwave and is better than GFS but it does still wants to put pressure on the ridge from both flanks and is downgrading from prior output. Seems to be good support for the Atlantic to break through in operational output but not conclusively. 

That means there will be scope for it to stay cold for a few days more but 6 or 7 days is starting to look like the best we can do and we will need UKMO type output to be correct rather than GFS which is now offering a very ordinary 3 day cooler spell.

 

Still time for a change for the better but it is very rare the models Uturn again once they have started to degrade a cold spell.

If they do though we then look to the SW and the Azores low but for now I will be concentrating on the crucial developments out to 120 and hoping ECM is more in line with UKMO because frankly what the GFS is offering is a kick in the teeth given the potential we had.

 

The key thing form your screen grabs is the lack of a formed Polar Vortex. During Dec, everyone was banging on about losing this and as it stands it's not reformed by any means.

Therefore what we have now is a variation on a theme, and whilst the model output is not looking pretty, we are in a much better state overall than we were a couple of weeks ago.

Unless I'm talking out of my back end, I can't see a return to raging south-westerlies anyway, and some colder outcomes have got to be possible with the North Hemisphere like this. And also remember it's only the 8th January - there's a helluva lot of winter left yet.

Edited January 8, 2016 by Paul_1978
Spelling mistake

[Mucka]

God bless GEM

 

 

Edit @Paul_1978 (post above) 

I say nothing about future prospects, I'm only discussing current synoptic 4 to 10 days.

We are on the cusp of our first wintry spell of weather and I am focusing on that for now.

 

Edited January 8, 2016 by Mucka

[snowray]

19 minutes ago, mountain shadow said:

Rather embarrassing for the met man who draws the Faxes.  Who would have thought the GFS would smash the UKMET model.

Who would have thought that it was the GFS 18z from two nights ago that first spotted this trend, I will never take the P out of the pub run again after this lot!

[karlos1983]

Don't worry everyone, GEM pulls it out of the bag with a BOOM chart

 

Ha Mucka, your turn to beat me to it. I'm going to bed on that chart.

Edited January 8, 2016 by karlos1983

[tight isobar]

Not long for the 12z Ecm.If aanything im even less convinced' far to much eratic energy from the eastern seaboard and differentiation' on the ridge and occupation @greenland...so many dynamics its not a wonder of the 12z.. so far..eyes on ecm.

[blitzen]

Isn't the GEM model the only one that Joe B has insisted has had this future cold spell nailed correctly from the beginning?   Other forecasters' on his twitter feed the other day were calling their own model  an embarrassment.   Time will tell I suppose.

[IDO]

1 minute ago, Earnest Easterly* said:

The UKMO has most definitely not drifted alongside GFS!!

UKMO T144 charts have proved worthless over the last couple of weeks when a bit of entropy is thrown in the mix, see my earlier post on how yesterday's T144 chart was totally wrong. Taking that D6 chart serious is really pointless after recent efforts.

I know some posters do not think that ex-tropical storm is the cause, but we saw with Storm Frank how such systems can effect the mid to high latitudes and this one has totally altered what looked a promising Atlantic Ridge. It has become the driver for the WAA and developed HP to its east and then has changed the whole Atlantic quadrant pattern:

Just another run and until we get ensemble and cross model agreement it remains that. Though it is a disappointing trend and I think at this range we would like the trend to be an improvement rather than downgrades. D10 and the NH profile looks rather bland:

[Duane S.]

It seems a lot if people are missing the point. While there is the sort of short term divergence such as is graphically displayed between the UKMO, GFS and GEM, how can we be sure if anything? Everything is far too messy to draw any conclusions. As for upgrades not being likely because of today's output. I don't buy it, with the current uncertainties, I see no reason why not.

[mb018538]

All eyes on ecm tonight.....I'm fully expecting the gfs 12z operational to be a mild outlier once more

[Man With Beard]

Not only has GFS lost the cold feed for the UK by T168, it has changed the entire northern hemispheric profile! Mad!!

[karlos1983]

Last one from me you'll be glad to hear until the ECM has rolled out. But I just don't buy the GFS, I don't know what it is, but this chart just looks so complex that it is putting real doubt in my mind. I could and am probably wrong. 

Perhaps an update on whether our Torpedo has launched, is airborne or has fell into the ocean and isn't transmitting a signal could help us.....

[phil nw.]

Different details again on the GFS and UKMO runs but we still get the cold coming through on the 12/13th which has always been depicted on the ens.

Maybe not perfection on the GFS but we retain the cold uppers until the end of the high resolution T192hrs.

UKMO would be cold too and the extended Euro trough into the Atlantic prevents the Euro ridge building this way.

Lot's to be resolved yet with continuing signs of vortex splitting so no need to be downbeat.

 

Edited January 8, 2016 by phil nw.

[Summer Sun]

The crucial thing from the models again is next week is looking a lot drier giving all the areas hit by flooding a welcome respite and chance to clean up

Next week is also looking much colder than we've experienced so far this winter with the coldest conditions probably coming towards the end of the week

Into the weekend milder air moves in from the west as per the 06z

So colder next week and drier though some wintry showers are likely at times then a change back to milder air is possible during the weekend

[Day 10]

The positive from all this is the uncertainty and as long as this remains the case then we still have snow chances not no chances.

Let's see what the ECM comes up with early on, it may be different again?

Edited January 8, 2016 by Minus 10

[radiohead]

JMA looks a little better than the GFS at T84. Not hugely different, but still better.

[Cheshire Freeze]

Looking at the output this evening, we've all been led up the garden path. I should have stuck to my guns about what I said the other night. GFS is grim, nothing else to say...a few wintry showers and a couple of frosts that you could get with any old toppler scenario. 

GFS wants us back amongst the plumes!

[Chris K]

Indeed SS, a good window for some places to dry out and I'm happy to see a few frosts after last month haha....

I'm just waiting to hear from our resident experts on whether this was expected at all and are things are still on course later this month & Feb for other potential opportunities for the cold/snow gang...? Just hoping it isn't scuppered each time with new small scale developments...

 

[Mucka]

13 minutes ago, s4lancia said:

It seems a lot if people are missing the point. While there is the sort of short term divergence such as is graphically displayed between the UKMO, GFS and GEM, how can we be sure if anything? Everything is far too messy to draw any conclusions. As for upgrades not being likely because of today's output. I don't buy it, with the current uncertainties, I see no reason why not.

It is just a matter of historically how things go, once the downgrades begin the models very rarely switch back to show the original promise.

Sure we can get much better output than this afternoons GFS which I think is a worse case scanario but is that an upgrade?

Depends how we see things but hard to believe w will see the great winter charts of 48 hours ago magically reappear in these time-frames and the 850's have also been downgraded in the run up to the colder spell. 

We were looking at this for around mid month

 

I don't think we can get back there but there is plenty of scope for the Atlantic incursion to be cool and messy and rather temporary so yes being optimistic we may just see a brief milder spell and a renewed blocking reestablish. I'm certainly not writing off anything for my part other than the models going back to the output the very cold output they were showing for the same timescales and I am happy to be proved wrong on that a la GEM type output from ECM this evening - please!

 

Edited January 8, 2016 by Mucka

[Alexis]

26 minutes ago, Earnest Easterly* said:

The UKMO has most definitely not drifted alongside GFS!!

Exactly. Ignore the UK for a second and imagine we're living in Iceland - quite different synoptics from the two models.

[mountain shadow]

I think what this highlights again is how a shortwave can scupper any cold promise from the long wave pattern.

Remember the NOAA  anomalies from yesterday which was projecting a long wave pattern with a massive Greenland height anomaly and subsequent Northerlies for the UK. In that same timeframe the GFS now offers a Southerly.

It's an argument I've had before with John Holmes,  but those anomaly charts have once again proven useless when a cold pattern is in the offing.