Model output discussion - 5th December 2016 - Into Winter we go

[Ali1977]

6 minutes ago, Johnp said:

Definitely seems to have taken a step back this morning on all models.

Christmas not looking as cold + longer term promise seems to have vanished.

 

I'm abroad 1st week of Jan, it's always snows when I'm not here so winter isn't far away. The METO are seeing signs of a colder looking Jan so personally I'm quite confident, even though Dec has come to nothing.

[knocker]

9 minutes ago, Johnp said:

Definitely seems to have taken a step back this morning on all models.

Christmas not looking as cold + longer term promise seems to have vanished.

 

I'm not sure what you base that on as the GEFS anomaly is still indicating retrogression of the vortex lobe over Greenland to Canada the movement west of positive anomalies to the east of the UK ( albeit nothing mind boggling) and the EPS isn't out yet.

Of course I could be making an unwarranted assumption of what you mean by promise.

Edited December 17, 2016 by knocker

[northwestsnow]

2 minutes ago, karlos1983 said:

One thing I've noticed this morning is the distinct lack of deep cold modelled at D10. 

Wouldn't it be fitting if we were to get an easterly when the uppers aren't great. 

North westerly toppler 

[Banbury]

32 minutes ago, Johnp said:

Definitely seems to have taken a step back this morning on all models.

Christmas not looking as cold + longer term promise seems to have vanished.

 

I would disagree with that in a nice way of course

The control is on the high side of the ENS but the chart I have posted shows so much promise , I wouldn't be too downbeat if I was you

EDIT What I will say is there is still no sign of model agreement on cold , all I see is lower temps from an HP  close by. To be fair nothing has been shown all December ( for wintry conditions ) . But a high sat to our East such as the control ive posted will give chilly dry conditions

Edited December 17, 2016 by Banbury

[IDO]

Yes it is amazing that there has been some requests for a return to cool zonal wet and windy weather. For the S/SE/SW it is the most miserable of setups a Winter can spawn. 

The latest trend for the GEFS in FI is the Euro high to sink further south allowing the UK to be a stop on the zonal train. With the colder air running off what remains a disorganised PV there will be opportunity for PM air to cross, modified probably, giving cold rain to the majority and fleeting as likely a mini ridge follows in the wake. 

I am however far from convinced of the GFS op this morning and hope it is not the trend going forward; it is possible the heights from the Atlantic/Azores are being underestimated and the jet will be further north (favouring the SE for less unsettled), though with the PV's ongoing growth the potential for the Azores ridge pattern dampens.

What is clear is that the background signals look diluted as there is currently no strong signs of Pacific forcing showing up as we enter January. That leaves little hope of a strong block building, just heights moving with the flow. No sign of a shift long term of the Euro heights, so very little hope of cold to S/SE UK in the medium term, as the GEFS highlight:

Two weeks more of Winter wiped if these are close to reality.

[Seasonality]

Why does the 18z so often appear to do colder uppers that get taken away by the 00z? I know this must be in my imagination somewhat! So frustrating.

[jvenge]

5 minutes ago, Seasonality said:

Why does the 18z so often appear to do colder uppers that get taken away by the 00z? I know this must be in my imagination somewhat! So frustrating.

ECM giving you a dusting on Christmas day, but drenches you in rain a few days later.

 

[Frosty.]

Nice cold end to the Ecm 00z with wintry showers and even before that there is some cold zonality, especially across the north.

[Iceaxecrampon]

Fair bit of gloom on here following the 00z but Christmas Day looking good at altitude for those seeking a festive escape to Scafell Pike or Helvellyn. 

[Summer Sun]

Looking at ECM this morning it's delaying the low later in the week

12z

00z

UKMO 00z

Note the differences between the two in the Atlantic ECM has a sub 970mb low whereas UKMO doesn't

[bluearmy]

aleutian ridge looking more influential on the eps. 

the sceuro ridge less of a mean upper feature as the run progresses  but that is to be expected as the Pacific feature likely to have less spread. The anomolies indicate a sceuro ridge persisting.   So that would mean wave 2 pressure upcoming from the trop as we head towards the end the year. 

 

[karyo]

It is Saturday but the models are not in the mood to party!

A thoroughly uninspiring model output from all the main models. As often happens in Atlantic dominated set ups, the models show a bit of promise with southerly tracking jet and some polar air making it to the UK but as we approach the t0 those disappear or correct further north so we just get nothing.

The ECM in particular has taken several steps back this morning by not taking any of the jet south while yesterday it was showing a half promising set up with some energy entering the Med.

The 30hpa stratospheric charts from the gfs show the vortex centred in the Arctic with very little ridging and that takes us to the 2nd January. So unlikely to see any help from the stratosphere any time soon.

Karyo

[carinthian]

7 minutes ago, karyo said:

It is Saturday but the models are not in the mood to party!

A thoroughly uninspiring model output from all the main models. As often happens in Atlantic dominated set ups, the models show a bit of promise with southerly tracking jet and some polar air making it to the UK but as we approach the t0 those disappear or correct further north so we just get nothing.

The ECM in particular has taken several steps back this morning by not taking any of the jet south while yesterday it was showing a half promising set up with some energy entering the Med.

The 30hpa stratospheric charts from the gfs show the vortex centred in the Arctic with very little ridging and that takes us to the 2nd January. So unlikely to see any help from the stratosphere any time soon.

Karyo

Yep, the UKMO picture does not show unsettled weather sweeping south at 144h, only a rise of pressure from the Azores and pushes the fronts back . Maybe the next wave out in Mid -Atlantic could sweep through as indicated on their N Atlantic chart at 168t.  Still not sure if this change is set in stone yet.

 C

[karyo]

4 minutes ago, carinthian said:

Yep, the UKMO picture does not show unsettled weather sweeping south at 144h, only a rise of pressure from the Azores and pushes the fronts back . Maybe the next wave out in Mid -Atlantic could sweep through as indicated on their N Atlantic chart at 168t.  Still not sure if this change is set in stone yet.

 C

That little low in Southern Italy needs some reinforcement but the Atlantic lows keep spinning around Greenland.

I wish the Azores would pull west for once to allow a northwesterly but we are stuck in this pattern.

[carinthian]

8 minutes ago, karyo said:

That little low in Southern Italy needs some reinforcement but the Atlantic lows keep spinning around Greenland.

I wish the Azores would pull west for once to allow a northwesterly but we are stuck in this pattern.

Yes KARYO, Look at the extent of the Northern Hemisphere mid - latitude blocking, even the USA looks like having limited amplification. It will take something to break this mode. We just have to sit and see it through. Plenty of time yet.

 C

[daz_4]

Once again, models found a way to downgrade already poor setup.

 

[carinthian]

OK, best leave it here at 144t, almost in the reliable time span. The end of next week still looks settled across much of Southern Britain, probably with fairly low temps. The far north a bit more unsettled. The Christmas weekend I think still not decided, it all depends if we can get enough amplfication in the flow to drive the fronts into the block. Not sure this is going to happen.

 C

[Summer Sun]

GFS backing away from the Christmas storm on this run still unsettled but nothing major

[Seasonality]

A southern scandi  block building in FI this time. Need it to push a bit further north but it is a strong one! 

[Summer Sun]

Anyone with a bet on Glasgow and maybe Edinburgh will be hoping GFS 06z is on the money

[blizzard81]

2 minutes ago, Seasonality said:

A southern scandi  block building in FI this time. Need it to push a bit further north but it is a strong one! 

Indeed but is the gfs 06z going off on one again or will this be replicated on future runs? As ever, more runs needed.

[karlos1983]

Would certainly feel more seasonal on the big day if the 06z were to verify. For me the form horse now is a North westerly flow on or around Christmas Day. It's been shown a number of times in recent runs. 

Certainly wouldn't feel very mild, and a fair  few would get pretty luck with this setup.

 

Edited December 17, 2016 by karlos1983

[Seasonality]

3 minutes ago, blizzard81 said:

Indeed but is the gfs 06z going off on one again or will this be replicated on future runs? As ever, more runs needed.

I know, the sceptical voice in the back of my head is saying the same thing. Also it ends up as another UK high, deja vu anyone?

[blizzard81]

Wouldn't it be great if the ops started to pick up a trend whereby the block to the east locates further north and lows start to undercut from the atlantic. I wouldn't be surprised to see some operationals like that in the next couple of days. Maybe wishful thinking of course

Edited December 17, 2016 by blizzard81

[legritter]

Morning gang ,yes plenty of synoptic possibilitys have shown themselves over the past day or so ,lets hope the cold ones win out . untill though this euro block shows its hand we cannot realy see which way we are heading ,a couple of days ago it looked like low after low was going to give us a bit of everything ,but now we have high pressure increasingly controlling from the east ,so as usual gang patience is the key ,right, up in the loft for decs ,And STellas on ice for later ,cheers