Model output discussion - 1st December onwards

[knocker]

Well the ecm isn't any better regarding systems traversing the UK in the next ten days bringing more rain and windy interludes unless you are looking at different charts to me.

Edited December 30, 2015 by knocker

[northwestsnow]

8 minutes ago, shaky said:

Woke up looking ath the posts here and youd think the atlantic has barrelled through and the scandi high has been blown apart!!absolutely ridiculous!!!so i thought i would check the models and to my eyes ecm looks better than it did yesterday same time and ukmo is not bad either!!gfs is obviously known to go crazy with deep lows so that 144 hour chart will probably not look like that come closer to the time!!heights look better to our north this morning aswell!!

Morning shaky - i really enjoy your posts and like you i try to be positive but really is there much to be positive about this morning?

All 3 show the Atlantic in charge and a lot of wet and windy to come, i can't see anything else hand on heart.

[Liam J]

As Weather History said it's not really a Scandi high as the core of heights are always too far east, and looking at the ECM T96 onwards heights retreat further away leaving the door open for the Atlantic with no real let up in the unsettled conditions as Knocker says above. 

Edited December 30, 2015 by *Sub*Zero*

[Interitus]

52 minutes ago, kumquat said:

If there's anything to strawclutch (I know you're not doing this mucka) the crazy warm winds tonight moving south to north. One would expect to pump up the Scandi High. This just isn't usual behaviour. There's something a bit alien about this.

Longyearbyen airport on Svalbard at 78°N just last 'night' recorded their highest December temperature on record with 8.1°C (may be higher when confirmed at the end of the recording period) beating the previous high of 7.2°C from 1995. It's also higher than the November and April records of 7.5°C.

[cyclonic happiness]

3 minutes ago, Interitus said:

Longyearbyen airport on Svalbard at 78°N just last 'night' recorded their highest December temperature on record with 8.1°C (may be higher when confirmed at the end of the recording period) beating the previous high of 7.2°C from 1995. It's also higher than the November and April records of 7.5°C.

So where is all the cold air being displaced to? Or is it just not there to begin with?  We're either going to get record breaking cold or war out of this set up, I can't see the models being able to handle such an unprecedented setup.

It's both extremely frustrating and yet fascinating.

 

(makes me feel better that even the Arctic can't get below freezing )

[Weather-history]

17 minutes ago, *Sub*Zero* said:

As Weather History said it's not really a Scandi high as the core of heights are always too far east, and looking at the ECM T96 onwards heights retreat further away leaving the door open for the Atlantic with no real let up in the unsettled conditions as Knocker says above. 

Some may seem this as being pedantic, a technicality but actually this is the problem.

This is a Scandi high

[northwestsnow]

3 minutes ago, Weather-history said:

Some may seem this as being pedantic, a technicality but actually this is the problem.

This is a Scandi high

Yes i think your spot on WH.

The core of the blocking to the NE is just a little too far away to force the jet as far south as we need it.

If this high is not going to produce i think i would rather it buggered off as its going to do nothing but slow down Atlantic systems pretty much across our soggy depressed shores.

[Gustywind]

Didn't we have a similar issue with a large scrussian high a couple of years ago - 2013/14?? It teased and tantalised us during Jan and Feb but delivered nothing to us in the end other than helping to deflect the Atlantic over the south UK contributing to all the flooding and non stop rain we saw that winter?

I recall Weather History making similar comments back then that the core of the heights was too far north east.

Not 100% on the year though just know it wasn't last winter.

[West is Best]

1 minute ago, Gustywind said:

 scrussian high

Love this.

I'm still not sure that I see the reasons for pessimism in, for instance, the ECM nor UKMO. 

Back in the day I'd always advocate that we look upstream not downstream: to the jet strength and pattern coming off the eastern seaboard. If you follow the NW jet stream links this is where I think the problem lies. It's fast, flat and furious.

[IDO]

Our main hope was that the Atlantic would not push the block east so that we could get a cold disruptive trough over the UK.  At the moment it looks like the vortex lobe over the NW is just too strong and will push the pattern east so any benefit from the undercut for cold will miss the UK.

The LR models have been consistent as have the means and the CFS for week 3 and 4 suggests that the UK will be the target for the Atlantic with the change in pattern being the opposite to what we wanted, now a zonal PM and TM:

w1 & w2: w3 & w4: 

We can only hope that this will bring a better "big picture" response, as early-mid January doesn't look very promising at the moment.

There is still a chance that the models are underestimating the block or over doing the Atlantic, as GEM shows with the UK at the centre of an east and west battle. It stalls and fills the upper low in the Atlantic rather than over the UK (as per GFS):

GEM At D10:  GFS 10 day rain totals: 

I suspect, as usual the GFS is too progressive and the 0z OP run over does the Atlantic, but this is just dampening the wet outlook, as even the most optimistic cannot turn the current charts into anything  long term cold, just how wet it will be and whether it is cool rain (snow high ground possible). Looking at the GEFS and the majority do not ramp up the Atlantic as much as the op. Somewhere in the middle of the models is usually the best call at this range, so the ECM at D10 (for a change) may be nearer the mark.

 

 

 

Edited December 30, 2015 by IDO

[knocker]

To digress a little. GFS temp animation of the Arctic

http://cci-reanalyzer.org/Forecasts/

[Duane S.]

Poor charts this morning but expect them to be all over the place in the next week or so. Nothing has changed, a quick route to cold following the impressive WAA surge in towards the Pole over to our East was always going to be a long shot and so it still seems. There is a window at D5 but the jet puts pay to that, slamming it firmly shut.  Mid Jan still for me, let's get a -AO in first and see where it takes us. 

[Polar Maritime]

Some very nearly record breaking temps being pushed up into the Arctic by storm Fred Knocks.

 

Edited December 30, 2015 by Polar Maritime

[johnholmes]

My attempt to sum up using as a start point the anomaly charts but also having looked in some detail at other outputs.

I have been without any internet access other than a mobile phone for 2 days so it is not easy to pick up how any model of whatever length from T+00 has been showing.

Using what is available today and comparing with my files of 2 days ago.

Noaa

 

6-10 and it looks much as one above in most aspects, so a trough 50-60N and a ridge n of this from nw of Alaska through Greenland into northern Norway.

 

So what will this mean at the surface=hard to be sure

 

Generally at 500mb an atlantic flow across from the eastern seaboard, decreasing strengths as it nears the uk (especially the northern half), well really all parts other than the extreme south., ridging at 500mb north of 60N across much of northern hemisphere. This leaves me wondering just where any surface high will set up, nw of uk, n or ne? I am again far from sure where. The –ve anomaly suggests a low at 500mb and probably a surface feature beneath it sitting about 20west. Not really giving any deep cold air for the greater part of the uk. Heights over the far south shown as about 546dm, neither warm nor cold really for this time of the year, originating over southern Alaska so not really deep cold sourced.

 

Summing up I would suggest, nothing like as mild as have had for many days. No deep cold other than fairly briefly behind surface lows that seem likely to run across the Atlantic and turn NE towards northern Scotland. Maybe another 2-3 days will make things clearer, both for the upper air pattern and where the major surface features will be?

 

links below to anomaly charts and UK Met basic model 144h etc

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.weathercharts.org/ukmomslp.htm

other links to look at MJO

was as far as I got last night, so the links will update so not sure what they are showing now, unable to do more links.

Still think my summary is about right from what we have available

 

Tue 29dec   

Edited December 30, 2015 by johnholmes

[bobbydog]

2 hours ago, Timmytour said:

 I think the day of joy and day of gloom cycle is a common theme in these kind of situations.  i imagine many good spells in the past would have been preceded by such spells in the past with such close scrutiny of every run of every model. In fact it's a sense of being in this cycle that gives me cause for optimism that the cold weather will eventually prevail, and I fully expect the hunt for cold to be re-invigorated as the day wears on

However  at the same time I take my hat off to chief" cold hunt saboteur" Knocker.... he's been mostly relentless in his view, taken from his reading of the models than his preference imo, that the cold is not coming, sometimes flying in the face of some resounding optimistic readings of model runs.  I sometimes think that, much as it can be easy to criticise the ability of anomaly charts to pick up on changing trends, anyone with a particular interest in calling what the weather will be, invariably will have a higher rate of success in predicting it by using them.

What's driving my current optimism is only a gut feel about my perception of the current volatility in the day to day model runs.  But tbh if i wanted a reputation for being accurate rather than wanting my wishes to come true, I know i could do worse than follow Knocker!

therefore, in fairness, Knocker should be the new 'Chosen One'...

[Polar Maritime]

Lets please stick to sensible discussion around the model outputs in here, There is a banter thread open 

Thanks.

Edited December 30, 2015 by Polar Maritime

[tight isobar]

57 minutes ago, Polar Maritime said:

S nme very nearly record breaking temps being pushed up into the Arctic by storm Fred Knocks.

 

Some bizzare weather atm.

With such sure of warmth being pumped INto the arctIc

Will only cause more model data/output' confuse

[forecaster]

11 hours ago, Singularity said:

 

 

Why does an increase in AAM help disrupt the polar vortex?

[Ali1977]

 I expect to see some big differences between runs, especially in FI. I think the chance of any easterly influence has gone, things defo look at becoming more stormy next week, not cold but not as warm as of late. 2nd week of Jan I anything could happen, interesting model watching ahead and look out for quick changes in pattern.

[Polar Maritime]

52 minutes ago, forecaster said:

Why does an increase in AAM help disrupt the polar vortex?

It aids to push the PV to lower latitudes and disrupts it's normal momentum by splitting the Jet. As we have seen in recent days this is were the models struggle as to where and how much effect this has creating wild swings in the outputs.

Edited December 30, 2015 by Polar Maritime

[Harsh Climate]

1 hour ago, Snowmut said:

In summary :-

ECM =           GFS =     

 

UKMO=  best of a bad bunch!  (couldn't get image,you'll have to use your imagination)

Overall =         ( Gibby eat your heart out) 

 

Excellent summary :D. Quite awful charts this morning! Just seems like the winter of discontent for all cold lovers and people fed up of their property getting flooded..

As ever though one week from now things could look very different and the charts could be showing the beast from the east at 144h+, I think when big cold spells do crop up it's literally overnight a stellar run is produced, backed up by further runs, then in the space of 48 hours you have a complete change around. 

Looking at the upstream signals and all this mild air heading into northern lattitudes I think somethings got to give and we will see this big change, in a couple of weeks or so as down stream responds if you will to the upstream. My bet is to write off the next couple of weeks off and look out for end of january/early februrary for things to become interesting with real cold/snow becoming a reality.

Edited December 30, 2015 by Harsh Climate

[knocker]

The ext ecm this morning is showing the expected pattern change upstream with a trough down the eastern side of N. America, And height rises in the eastern Atlantic over the UK which are well established by the 14th. A signal that was supported by the GEFS this morning so certainly hope for some more settled weather. I couldn't give a toss whether it's warm, cold or indifferent.

Regarding calls for my beatification..............alas I've already been defrocked.

Edited December 30, 2015 by knocker

[Shuga ice]

Too many posts claiming poor charts for cold lovers.  Nothing has changed over the past few days, it's just the charts playing out different scenarios.  One day the easterly is on then the next day the easterly is off.  Which chart is correct?  In my experience, easterlies pop up at short notice so the charts a few days ago showing easterlies in 10 days time could be correct.  Time will tell.

[karlos1983]

I agree if it's instant cold you are after then this mornings models aren't for you. But I think a few are getting a bit hung up by each and every run. If we look at December when we were are all wondering how this winter can be recovered, but the pattern is definitely on the change. 

The easterly, whilst it would have been nice, was always going to be difficult to get to these shores. 

But looking at the main 3 ECM, UKMO & GFS at 144 hrs, just cast your mind back a couple of weeks when all looked completely hopeless.

PV all over the place, height rises in the pole vacinity, all to play for!

The next couple of weeks looks set to be a really interesting period of model watching, and I like others think mid Jan onwards is when the fun starts in terms of cold.

Edited December 30, 2015 by karlos1983

[shaky]

As if by magic the deep low is gone on the gfs!!!colder air slightly further west on this run?