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

[Zakos]

 UKMO +144

 

GFS +144

Excellent UKMO

Siberian High is much stronger on the UKMO throughout the run than on the GFS, causing a more negative AO.

On the GFS in the later frames we see the Russian high strengthen, enlarge and start to back west towards the UK. 

Heights begin to rise over Scandinavia but are scuppered by the Atlantic.

 

GFS +196

Assuming the UKMO is accurate in maintaining the Atlantic ridge, if the Russian high is set to back west, could we potentially be looking at Atlantic High - Russian high link up?  possibly forming a Scandi High?

[karlos1983]

if we go back to yesterdays 12z from the GFS at +96 and compare it to the 12z from today at the same time frame, so 13:00 on Friday, you can already see the difference in the Atlantic, Heights are stronger further north and the features coming of the East coast of N America have a more negative tilt to them today.

This to me is a clear sign that the GFS was over progressive, I'm *not going to say it will swing to the UKMO completely, but it is moving towards it, no question about it. 

 

 

Edited January 12, 2016 by karlos1983

[doctor32]

ukmo @120, found some support for meto from gfs essembles  

 

some others too

Edited January 12, 2016 by doctor32

[warrenb]

I see around 6 maybe 7 that support the UKMO at 120 in the GEFS

[doctor32]

  perb 6 is good for an easterly

[Mucka]

Slowly, slowly...

GFS ensembles.

Ever so slowly more members getting on board with some form of undercut.

[weather eater]

2 hours ago, Midlands Ice Age said:

 

I do not understand many of the preceeding posts discussion....

 GFS is the one that has overstated the Greenland high. Not the other way round.

It was forecasting a high of 1055MB for the Greenie.

Both the ECM and MO had it at 1040.  The ECM was a very flabby affair -  The result was 1045mb.

So the Euros were better at predicting the lower pressure at that stage.

How can you  claim that it is better at not overcooking northern blocking as per the Euros? (from that chart)?

Looking further afield it has the main Euro trough centered over Poland.... Result - it is over The North Sea.

Admittedly it did show a superficial split low - but so did the ECM, and the ECM correctly forecast that the low over Scotland would be the main centre and not the GFS..

None of them spotted the remaining low pressure to the south of Greenland.

My verdict is the Euro's looks better with the overall pattern.

Am I  wrong or simply mis-reading?

 

 

Hi MIA Miss-reading, sorry if I was not clear enough. II was not referring to pressure but that the Euros are more prone to trying to stick with blocking patterns after the GFS has dropped the idea and we have seen that in both the last two winters. The GFS proving to be right. In the same way that the GFS has a tendency to be too progressive with the Atlantic the Euros are too progressive with blocks, slow to drop the idea as well. I simply cannot remember the Euros sticking with a block and the GFS caving in. Still there is always a first time and the UKMO is not backing down, an interesting ECM coming up I feel.

[Nick L]

Folks, several posts regarding the timing of snowfall have been moved to the cold spell thread. Please keep this model related. 

Thanks.

[captaincroc]

40 minutes ago, ukpaul said:

Support for UKMO from the short range Arpege model.

 

 

This for me is very important. The MO see this up there with one of the best. If this is on board then it's only a good thing.

[coldcomfort]

UKMO 144hr is proper eye candy this evening, but without some sort of support from ECM I'm not sure it can be taken too literally. As for the 12 GFS it is again nice to see a move towards an undercut, but unfortunately it does nothing other than delay the onset of milder southwesterlies, which I really can't get too enthused over at this stage. As ever more runs needed, starting with 12 ECM in half an hours time, but if it drifts too far from it's 00 counterpart I will be surprised.....pleasantly so however

 

[Weather Observer]

It was only 2 days ago that this thread became downbeat and some posters wondered winter might be over. Winter is never over on the 10th of January. I think one explanation for such pessimism is that recent Winters have been all or nothing. At some periods in this past they seemed more blended. Almost no snow before January, but then a good cold spell with some snow and often again in February. They may have been El Niño years, no one ever told us.

With the latest UKMO charts and GFS sniffing some snow in the wind, the dream lives on.

[Snowyowl9]

UKMO gets better every time I see it.

[Geordiesnow]

I think the important bit for this upcoming ECM run is whether it will side with the UKMO on decent ridging at 96 hours, it has moved towards it but still showing the potential of the Atlantic coming into play with a strengthening PV if albeit in FI whereas all the cold is at/near the start which makes a nice change. 

I would not be too surprised/disheartened if the ECM still stick to it previous outputs but hopefully we will see it trending towards the UKMO more with its stronger ridging like this mornings run did. 

Trend I can see is that the weather WILL turn colder through this week but as we approach the weekend, the cold looks a bit stronger however it should be drier so whilst snowfall looks quite limited/non existant this weekend, we should see some harsh night time frosts and lingering fog.

[nick sussex]

Lovely UKMO run and nice to see the GFS inching further west with each run today.

As for the upstream pattern NCEP have had criticisms for both the GFS/GEFS and ECM. In terms of the ECM they think its 00hrs run was too fast over the eastern USA on days 6 and 7.

 

[TSNWK]

definite trend in the right direction for cold from the GFS. I was just wondering how's today's UKMET 120 was looking against yesterday's 144.. 

 

Many thanks

[gottolovethisweather]

25 minutes ago, Mucka said:

Slowly, slowly...

GFS ensembles.

Ever so slowly more members getting on board with some form of undercut.

At what timeframe is this so-called undercut mucka, where should my eyes be drawn to it on the charts?

[Midlands Ice Age]

59 minutes ago, weather eater said:

Hi MIA Miss-reading, sorry if I was not clear enough. II was not referring to pressure but that the Euros are more prone to trying to stick with blocking patterns after the GFS has dropped the idea and we have seen that in both the last two winters. The GFS proving to be right. In the same way that the GFS has a tendency to be too progressive with the Atlantic the Euros are too progressive with blocks, slow to drop the idea as well. I simply cannot remember the Euros sticking with a block and the GFS caving in. Still there is always a first time and the UKMO is not backing down, an interesting ECM coming up I feel.

 

Thanks for the reply weather eater.

It was not aimed directly at your post, but at the whole lot of posts using the series of charts to claim that the GFS had outperformed the Euros. I just could not see it from that series of charts.

Anyway enough now ..... lets get on with the fireworks and pray that the ECM changes  to start to show an undercut.

If it does for me its getting close to game over

Edited January 12, 2016 by Midlands Ice Age

[Nick L]

1 minute ago, Midlands Ice Age said:

 

 

Sorry how do we get rid of the extra quotes above?

Thanks for the reply weather eater.

It was not aimed directly at your post, but at the whole lot of posts using the series of charts to claim that the GFS had outperformed the Euros. I just could not see it from that series of charts.

Anyway enough now ..... lets get on with the fireworks and pray that the ECM changes  to start to show an undercut.

If it does for me its getting close to game over

To get rid of quotes, click the top of the quote box in the editor (where you see how long ago the post was and who by) and hit delete on your keyboard.

[feb1991blizzard]

4 minutes ago, TSNWK said:

definite trend in the right direction for cold from the GFS. I was just wondering how's today's UKMET 120 was looking against yesterday's 144.. 

 

Many thanks

Edited January 12, 2016 by feb1991blizzard

[karlos1983]

3 minutes ago, gottolovethisweather said:

At what timeframe is this so-called undercut mucka, where should my eyes be drawn to it on the charts?

from about +96 @gottolovethisweather 

example of attempt Purb

Edited January 12, 2016 by karlos1983

[nick sussex]

The GFS seems to be living off one right call re the Icelandic shortwave and is like one of those awful Z list celebrities who desperately try and milk one moment in the sun!

Hopefully the ECM will slow down upstream and theres a good chance of that given comments from NCEP. Although there might be some middle ground solution eventually it certainly won't be looking like what the GFS had been proposing all day yesterday.

 

[fromey]

Well to put it out there Matt Hugo seems to think the overall signal is a return to swlys and the meto is playing catch up!!

answers on a post card!!

[TSNWK]

2 minutes ago, feb1991blizzard said:

Many thanks.. So another good trend for tonight in my view is that tonight's UkMet 120 is even better than last nights 144.

stronger heights to the northwest but a significant difference and increase in the amount of energy heading Canada..so on one hand good with the heights, on the other.. Well I'm not actually too sure..

[Kentish Snowman in Yorks]

58 minutes ago, Weather Boy said:

Maybe old age is playing tricks with my memory, but I thought that it was UKMO that was the most determined to bring the easterly in and GFS was the first to sniff that it was not going to happen.

Very happy to be corrected.

It will be a major embarrassment for the GFS with all its ensembles against UKMO if it is wrong.  However, for that very same reason, I would tip GFS rather than UKMO.

But are you tipping the GFS output from yesterday or today?

The GFS is slowly but surely backtracking with regard to the Eastwards progress of the low but the UKMO has been rock solid in its modelling of the situation.

I know where my money is!

[Captain Shortwave]

It is all about the strength and angle of that ridge near the UK at day 4.

UKMO

Very good, you can see the hallmarks of a cut off high developing north/north west of the UK at this point as the high over the UK collapses away with low pressure cutting in underneath the remaining heights to our north.

GFS

Weaker with this and a much deeper low south of Greenland, no surprise to see a much more westerly based solution albeit it takes two attempts to push mild air in. The first attempt would bring snow to areas along the battleground.

GEM

Again a weaker effort than the UKMO, more north rather than north west on that ridge too.

We might as well include this model. The Arpege

Not far off the UKMO solution at this time with T114 showing the undercut beginning with the ridge sheering away allowing low heights to drive underneath.

 

So all up for grabs still I feel. The ECM will decide of course what outcome we should favour for now.