Winter Model Discussion - The Hunt For Cold -12z 14/12/12

[Methuselah]

Would'nt gibby's excellant anylasis be better suited to a specific thread (members forecast thread) instead of being lost in the fast paced model discussion thread ?

As this thread is dedicated to the model-output, it seems sensible for Gibby's summaries to be included. The fact that there might be one, two, even three colder-than-average ensemble members doesn't really detract from what he's saying IMO...

The models are not the weather...the weather does not have multiple runs.

[chris55]

ECM mean at 168,

[Duane S.]

Well some slightly more encouraging signs from the MJO, with both the ECM and GFS suites moving things towards phase 3 - which at least raises heights out in the atlantic (Should be read - potential for reduction of atlantic energy), and also suggests the height anomaly over Siberia would ridge westwards

How much of a driver is the MJO at present? Well the currently progged transition into phase 2 corresponds well to the impending pattern:

SK

I suspect MJO has been a big hinderance at best, a primary driver at worst, so the sooner out of phase 2 the better I would say.

The op when compared to the ens give us more optimism

[Paul T]

LOL the gfs is all over the place showing wildly different outcomes every run, for consistancy, the ecm is more solid and that's not because it shows a possible colder trend, gfs is very unreliable.

Appreciate your perspective. More hopeful than accurate in my view.

I would love to see cold opportunities within 168 to 192, but I can not see it happening. More than happy to have egg on my face!

[Summer Sun]

They are usually copied in the Summaries thread here suxer.

http://forum.netweat.../page__st__1840

i will paste his latest one in there.

That link doesn't work all I get is Sorry, we couldn't find that!

[chris55]

Control goes sub zero around Christmas!!! Still plenty of scatter and the colder options are away from the main cluster, but some hope in there for a seasonal weather type for the holiday period!

Also remember these are for Holland which is quite a way south for the colder air to get if it's an undercut easterly we are looking for, will need to see the postage stamps to get an idea of synoptics associated. Renders the mean at day 8/9/10 a little pointless as well with such a spread.

Edited December 14, 2012 by chris55

[bobbydog]

LOL the gfs is all over the place showing wildly different outcomes every run, for consistancy, the ecm is more solid and that's not because it shows a possible colder trend, gfs is very unreliable.

is it though?...... (something you should already know but...) the GFS is run four times a day with a slightly different data set each time, therefore it will come out with a different outcome each time. if the variances of each data set are small and the weather patterns are less chaotic then the outcomes will be more consistent. also the GFS has a longer range than the other "reliable" models therefore the outcomes at the end will be further apart. (looking at the ensembles demonstrates this well) don't forget, each run shows a possible outcome, none are impossible (some less likely than others but still possible)

it doesn't matter how "reliable" we think a model is, it's only as good as the input data at the time and as has been said a million times- the weather itself can change at very short notice and even a slight early change can have massive implications further down the line. more so when the setup is as complicated as it is right now and these frequent changes are fed into the computers with each run- hence the wild variation.

as has also been said a million times before, the models don't guide the weather, the weather guides the models.

[phil nw.]

That link doesn't work all I get is Sorry, we couldn't find that!

It seemed ok when i just clicked Gavin.Post 1843 on last page.

http://forum.netweat...40#entry2447801

Here try again see if this works for you.

[OldMetMan]

Today's output continues to be irritating with its dithering!

There are still basically 2 scenarios across the models in the medium to long term; one is the cold air E and N of us puts a brake on the Atlantic systems and two, the Atlantic systems just keep on coming. No one model seems to favour either particular outcome.

Once again, let's look at what evidence we have at the moment as to which way it will go.

The 500mb flow is quite revealing:

First thing to note is that, whilst LP has pushed in for the moment, we still have an upper high over Russia that's been there quite a while now but, interestingly, we have a new 500mb high over Greenland that's been developing these past 2 -3 days. This should, at least for now, keep any LPs further south than they might otherwise go. I also think that this is one point in favour of us getting an easterly.

There is still a lot of energy heading SE in the E Pacific into the US and, whilst the situation there is fairly mobile, I would suggest at some point, as I mentioned yesterday, a more slow moving vortex will develop, possibly over the E of the US. The LP shown by most of the models emerging from the US around T120 could well be the key to this development by deepening and slowing down, again as I talked about yesterday. Given that we already have a 500mb over Greenland at the moment, this deepening LP could assist in maintaining this.

However, the models have other ideas and simply keep moving systems along across the Atlantic towards us and I do not believe that the essentially blocked pattern over the N Atlantic and Greenland is conducive to this, hence I believe we will see LP sliding away off the block,

This is a pattern that is probably one of the most difficult for the models to get to grips with but I think there should be a bit more certainty within a day or two - maybe!!

[Summer Sun]

It seemed ok when i just clicked Gavin.Post 1843 on last page.

http://forum.netweat...40#entry2447801

Here try again see if this works for you.

That link isn't working either managed to find it though -

[Frosty.]

is it though?...... (something you should already know but...) the GFS is run four times a day with a slightly different data set each time, therefore it will come out with a different outcome each time. if the variances of each data set are small and the weather patterns are less chaotic then the outcomes will be more consistent. also the GFS has a longer range than the other "reliable" models therefore the outcomes at the end will be further apart. (looking at the ensembles demonstrates this well) don't forget, each run shows a possible outcome, none are impossible (some less likely than others but still possible)

it doesn't matter how "reliable" we think a model is, it's only as good as the input data at the time and as has been said a million times- the weather itself can change at very short notice and even a slight early change can have massive implications further down the line. more so when the setup is as complicated as it is right now and these frequent changes are fed into the computers with each run- hence the wild variation.

as has also been said a million times before, the models don't guide the weather, the weather guides the models.

True but I still feel more optimistic because it could go either way, some encouraging output and a few rank mild outliers in the mix. All to play for in my opinion but even by the end of the weekend, the outlook may not be resolved due to the increased complexity of the situation.

[welshwizard]

LOL the gfs is all over the place showing wildly different outcomes every run, for consistancy, the ecm is more solid and that's not because it shows a possible colder trend, gfs is very unreliable.

they are all very unreliable lol

[bobbydog]

True but I still feel more optimistic because it could go either way, some encouraging output and a few rank mild outliers in the mix. All to play for in my opinion but even by the end of the weekend, the outlook may not be resolved due to the increased complexity of the situation.

exactly my point. the complexity and uncertainty makes model watching much more interesting!

[Cheshire Freeze]

I disagree with the sentiment that the models are undecided. At this juncture the overwhelming majority of the evidence available to us from the NWP is suggestive of LP domination for some time to come.

216 hr ECM...

216 hr GFS

At this juncture, I'm not interested in a few ensemble members which show cold as there are far more members showing mild!

For the life of me I cannot understand why there seems so much straw clutching RE weather for the rest of this month. The ECM doesn't look great this evening and the GFS 12z is a shocker. Even in the 00's winters we had points of excitement and interest in the synoptics such as...

We're rarely seeing such charts turning up even in FI at the minute but if we did we'd be biting the hands of the models off for such scenarios. Which just goes to show what a grim pattern we're in/facing at the minute!

Let's see what the week after Christmas brings!

Edited December 14, 2012 by CreweCold

[nick sussex]

Well after the rather underwhelming ECM operational run at least the ensembles show some more interesting options.

Interestingly the control and operational run look very similar over Europe at 168hrs but obviously have different upstream patterns at that point which lead to different outcomes.

Unfortunately with the ECM postage stamps we don't get a full view of the pattern which is a shame:

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2012121412!!/

[Duane S.]

Interesting comments tonight from the CPC folk leaning towards the ECM (mean, not op) of yesterday...

TODAY'S OFFICIAL 500-HPA BLEND CONSISTS OF 25 PERCENT OF TODAY'S 0Z GFS

ENSEMBLE MEAN CENTERED ON DAY 8...25 PERCENT OF TODAY'S 6Z GFS ENSEMBLE MEAN

CENTERED ON DAY 8...AND 50 PERCENT OF YESTERDAY'S 12Z EUROPEAN ENSEMBLE MEAN

CENTERED ON DAY 7.

MODEL OF THE DAY: YESTERDAYS 12Z ECMWF ENSEMBLE MEAN.

TODAYS 0/6Z GFS ENSEMBLE MEANS AND YESTERDAYS 12Z ECMWF ENSEMBLE MEAN DIVERGE

ON THE LOCATION OF A TROUGH AXIS NEAR THE EAST COAST DURING WEEK-2. TODAYS 0/6Z GFS ENSEMBLE MEANS FAVOR A PROGRESSIVE TROUGH WELL OFFSHORE THE EAST COAST, WHILE YESTERDAYS 12Z ECMWF ENSEMBLE MEAN MAINTAINS A TROUGH ACROSS THE EASTERN CONUS

Why do they HAVE TO USE CAPS though??

[suxer]

As this thread is dedicated to the model-output, it seems sensible for Gibby's summaries to be included. The fact that there might be one, two, even three colder-than-average ensemble members doesn't really detract from what he's saying IMO...

The models are not the weather...the weather does not have multiple runs.

Dont quite get that answer , just saying for a reasoned analysis if there was a thread for a summary as gibbys would n,t that be good ....?

[Severe Siberian icy blast]

I disagree with the sentiment that the models are undecided. At this juncture the overwhelming majority of the evidence available to us from the NWP is suggestive of LP domination for some time to come.

216 hr ECM...

216 hr GFS

At this juncture, I'm not interested in a few ensemble members which show cold as there are far more members showing mild!

For the life of me I cannot understand why there seems so much straw clutching RE weather for the rest of this month. The ECM doesn't look great this evening and the GFS 12z is a shocker. Even in the 00's winters we had points of excitement and interest in the synoptics such as...

We're rarely seeing such charts turning up even in FI at the minute but if we did we'd be biting the hands of the models off for such scenarios. Which just goes to show what a grim pattern we're in/facing at the minute!

Let's see what the week after Christmas brings!

You say things to wind people up, if you trust charts that's that far away then you must be very naive , we have changes much closer to the t100 mark which in turn changes the whole outlook ,

Very sad I'm afraid of you.

[Cheshire Freeze]

You say things to wind people up, if you trust charts that's that far away then you must be very naive , we have changes much closer to the t100 mark which in turn changes the whole outlook ,

Very sad I'm afraid of you.

Sorry mate I'm not saying anything to wind anyone up. I've summarised what the models are showing in a couple of sentences. No different to Gibby (Martin) and his diagnosis of today's models (which was an equally grim read into FI). If it makes it easier for you to think I'm on the wind up then crack on. Though guessing you haven't been on the forum as long as some people who will quite happily testify that I don't look for a reaction......I say things as I see them.

Also I'd go as far to say that 'sad' is rather more epitomised by the willingness of people to let their bias in weather preferences cloud their analytical capabilities (that's provided they have any in the first place!)

Edited December 14, 2012 by CreweCold

[Frosty.]

The cold block remains in place over to the NorthEast of the Uk. The gfs "tries" to blow that block away and the the ecm Quivvers with the idea of the cold affecting the Uk. I remain confident that this week we will see a turn around in the models and show a colder outlook for xmas ,almost so, that I feel I may have a White Christmas Bet.....!

I share your optimistic view, I was quite negative before the ecm 12z last night but there have been significant improvements in certain areas for at least the potential for cold air to make a comeback next week.

[Severe Siberian icy blast]

Sorry mate I'm not saying anything to wind anyone up. I've summarised what the models are showing in a couple of sentences. No different to Gibby (Martin) and his diagnosis of today's models (which was an equally grim read into FI). If it makes it easier for you to think I'm on the wind up then crack on. Though guessing you haven't been on the forum as long as some people who will quite happily testify that I don't look for a reaction......I say things as I see them.

Well iv been on the forum for 4 years now ( granted not been active much until more recently) but I feel as though you are always negative about things, you may say things as you see them but You do seem to over look trends and appear to state things from a glass half empty pov , everyone's different I suppose but looking at the models these last few days one can't deny the trend to something different , at least a battle rather than a zonal express.

Edited December 14, 2012 by Severe Siberian icy blast

[nick sussex]

Some strawclutching by myself but here goes. The latest 18hrs NAM for the USA makes less of that nuisance shortwave to the nw of the UK than the GFS 12hrs, so lets hope thats a sign for the GFS to get back into festive mode.

[Cheshire Freeze]

Well iv been on the forum for 4 years now ( granted not been active much until more recently) but I feel as though you are always negative about things, you may say things as you see them but You do seem to over look trends and appear to state things from a glass half empty pov , everyone's different I suppose but looking at the models these last few days one can't deny the trend to something different , at least a battle rather than a zonal express.

The thing is no amount of positivity or wishful thinking will change the situation. The weather isn't sentient. Take a far more realistic approach (expect nothing) and you won't end up crushed time and time again when things (almost inevitably) go wrong!

I've learned the hard way over the years!

Edited December 14, 2012 by CreweCold

[chionomaniac]

I disagree with the sentiment that the models are undecided. At this juncture the overwhelming majority of the evidence available to us from the NWP is suggestive of LP domination for some time to come.

216 hr ECM...

216 hr GFS

At this juncture, I'm not interested in a few ensemble members which show cold as there are far more members showing mild!

For the life of me I cannot understand why there seems so much straw clutching RE weather for the rest of this month. The ECM doesn't look great this evening and the GFS 12z is a shocker. Even in the 00's winters we had points of excitement and interest in the synoptics such as...

We're rarely seeing such charts turning up even in FI at the minute but if we did we'd be biting the hands of the models off for such scenarios. Which just goes to show what a grim pattern we're in/facing at the minute!

Let's see what the week after Christmas brings!

Ha, nothing like choosing a chart that the day before looks so similar to the one that you are trying to portray as grim that it makes the point that you are trying to make fall flat on its face!!!

Dec 28th 2000

ECM T+216

The only difference being is that the ECM T+216 has more amplification and therefore could be described as better.

Very very funny!

Edit - that is before we point out that you are comparing FI charts!

Edited December 14, 2012 by chionomaniac

[PolarWarsaw]

He's negative because the output for cold is around a 2/10 mark at the moment. The ENS, the teleconnections and all bar 1 or 2 ECM frames at a long distance out show absolute Atlantic and LP dominated conditions.

I'm willing to bet I want an outcome similar to most In this thread, but some of the straw clutching is unreal over the last couple of days. It feels like people are searching the 'chart stack' for a cold needle.

Bar Nick, are any of the major collies contributing to this thread? That alone, tells you enough.