Model Output Discussion 1st January 2014-06z onwards.

[forecaster]

There is a link somewhere on the NOAA site posted on netweather within the archives which suggests fewer balloons are released during the weekend period, hence I'm a believer in weekend runs having more wobbles than would be otherwise anticipated. Whether a few less observations have enough impact on the entire GEFS suite for example, would be up for debate. Back to the model discussion we better go, otherwise both of us will be in trouble, John. PM me for a chat if you wish.

 

I am not sure if balloons are as massively important as they once were, due to the quality of satellite soundings available nowadays. A real sounding (balloon) is better, but it's only for one point (or assumed to be for one point, despite drift during flight), but inferred soundings from satellite can cover the entire globe. 

[Paul]

There is a link somewhere on the NOAA site posted on netweather within the archives which suggests fewer balloons are released during the weekend period, hence I'm a believer in weekend runs having more wobbles than would be otherwise anticipated. Whether a few less observations have enough impact on the entire GEFS suite for example, would be up for debate. Back to the model discussion we better go, otherwise both of us will be in trouble, John. PM me for a chat if you wish.

 

I must admit, I've never seen or heard of that being an issue tbh.

[gottolovethisweather]

I am not sure if balloons are as massively important as they once were, due to the quality of satellite soundings available nowadays. A real sounding (balloon) is better, but it's only for one point (or assumed to be for one point, despite drift during flight), but inferred soundings from satellite can cover the entire globe. 

 

Thanks forecaster, radiosondes are the ones I'm referring to.

[gottolovethisweather]

I must admit, I've never seen or heard of that being an issue tbh.

 

If I had full access to any back-dated archives I know I read something somewhere, but as forecaster suggested and JH alike would be soon tell me, perhaps their importance has diminished over recent years. A couple links I've found should anyone be interested are as follows, fascinating enough anyhow.

 

http://weather.uwyo.edu/upperair/sounding.html

 

http://www.ncdc.noaa.gov/data-access/weather-balloon-data

 

http://www.erh.noaa.gov/iln/UpperAir/UpperAir1.html

 

Even then the above doesn't seemingly answer my question. Onwards now then to what tonight's ECM has to offer us, will it be a continuation of the Atlantic onslaught, I hope not for all those affected by this rather nasty weather.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2014010412/ECH1-144.GIF?04-0

 

ECM 144 - can we get any energy going SE not NE!Maybe @ 168

 

S 

[Summer Sun]

Certainly a different pattern starting to emerge now and thankfully its a less stormy one though we do have tomorrow and Monday to get through first

 

 

Starting to become cooler as well

[Mucka]

JMA so close bite 1 but will it work out bite 2?

 

[lassie23]

The latest Korean model suggests a big freeze from the east for the UK come February, it's on its own but at least it is there.

[SMU]

Yep MUCKA JMA the run of the day & the most seemless looking one- ECM looking bizzare at 168-

 

Another day of frustration......

 

Come back Monday eve is my advice

 

S

[Summer Sun]

High pressure incoming

 

[I remember Atlantic 252]

High pressure incoming

 

 

Wanna see these sort of charts appearing on GFS, then I will believe much drier weather on the way, rather than just a bit drier

[Summer Sun]

Some very cold air building to our east at t216

 

[Ali1977]

Cold incoming from the East maybe!!!

Edited January 4, 2014 by Ali1977

[Grimsby Snow Lover]

Cold incoming from the East maybe!!!

Not from that chart, but quite possibly from the latter end of the run. Something seems to be brewing though doesn't it.

[Summer Sun]

Cool and crisp end to ECM, after all the rain we've had lately a settled spell with be greatly welcomed by many

 

[Great Plum]

High pressure over Scandinavia by day 9 - not quite the right shape to get the cold to us, but still pleasing (and if it came off, it would be a lot cooler and drier!)

http://www.wetterzentrale.de/pics/Recm2161.gif

[Captain Shortwave]

Rather chilly looking end to the ECM, it's a little better, mainly for developing a slightly better cut off low over the Med which brings some cold air our way. Cold, dry and frosty sum it up. We need a trigger low or shortwave to go south east earlier on to support something more substantial than a slack south easterly.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2014010412/ECM1-240.GIF?04-0

 

Well ironically at 240 the ECM shows a very raw continental flow & a shallow system moving south across the UK in -3 to -5c air

 

http://www.meteociel.fr/modeles/ecmwf/runs/2014010412/ECF0-240.GIF?04-0

 

Possible snow there-

 

 

Anyway I much prefer the JMA solution with the heights holding in situ at a more Northerly locale ready for the second bite...

 

S

[weather eater]

A bit underwhelming but it’s good to see the ECM still going for some sort of block, If it sticks with it then it could well upgrade the cold potential in the coming days.

[Ukwoody]

Hi all, forgive my total lack of knowledge here, but just wondering about the Ice storm hitting NY and Canada. What is the possibility of that weather coming our way - even as more rain? Doesn't it often follow that what they get we get a week later - or is that an old wives tale??

 

Many thanks, Woody

[Grimsby Snow Lover]

Hi all, forgive my total lack of knowledge here, but just wondering about the Ice storm hitting NY and Canada. What is the possibility of that weather coming our way - even as more rain? Doesn't it often follow that what they get we get a week later - or is that an old wives tale?? Many thanks, Woody

A bit of an old wives tale really unfortunately. If any weather was to affect us from the US it would be in the form of wind and rain, any real cold for us usually comes from the North or East during winter months.

[Vorticity0123]

As the three main models have their (somewhat) reliable update time updated (T144), I'll give an attempt to highlight some interesting features that piqued my interest.

 

General trends

 

During the past week or so, many low pressure areas moved from Newfoundland toward Schotland while intensifying, to curve back toward the north and get absorbed by the next intense low pressure area. All low pressure areas were essentially blocked by the Russian High, which provided South-to-North steering currents on its western flank, as can be seen on the GFS charts below:

 

GFS T24 (12Z).

 

Focus on the low pressure area (or trough, was a 975 mb low at T0) just to the northeast of Iceland. It can be seen spiralling toward the dominant low (945 mb).

 

GFS T30 (12Z)

 

The low pressure area has moved southwestward closer to the main low's center. This has been the process that occured during the last couple of days. Moreover, the high pressure area over the pole is also barely visible to the extreme north.

 

However, at T102, the parent low (945 mb low in the charts above) broke this trend, moving into Scandinavia to be located over Finland (in a weakened state):

GFS T102 (12Z)

 

As a result, the Russian high has moved southeast and weakened considerably. The polar high has also become slightly more visible.

 

Differences in model output

 

To me, it looks like this is a possible point of change. This is also the point where the main models start to diverge. I'll compare the T144 from all models.

 

First, the GFS:

GFS T144 (12Z)

 

The GFS develops a weak high over Central Europe and Scandinavia, after the low has moved further eastward toward Siberia. However, the sitiuation is very fragile, with the Polar Vortex, along with very cold uppers, situated over Greenland This means that the increased heights could be short-lived. The cold uppers can be seen in the chart below:

GFS T144 (12Z)

 

The cold uppers provide an ideal breeding ground for deep low pressure areas, confirming the possible very bleak future for the Scandinavian high pressure area.

 

 

Next: the UKMET model:

UKMO T144 (12Z)

 

The UKMO also shows a Euro high, but the other high is situated over the north of Scandinavia, as an extension of the Polar high. If the highs could connect (which is not very likely given the PV above greenland --> intensifying lows relationship), it could become an interesting situation.

 

And finally, the ECMWF:

ECMWF T144 (12Z)

 

It once again shows the Euro high (the most southern position). The second high is a very poorly defined high to the north of Scandinavia. Also note the Polar high is no longer visible on this situation.

 

FI "trends"

 

The further progress of the ECMWF is a high to develop above Finland. However, it needs to be emphasized that this is too far out to tell anything sensible about it, as the GFS is showing a solution with a high pressure area quite some distance to the south of where the ECMWF is positioning it (T192).

 

Concluding, it looks like the situation will provide a chance of a cold snap to develop or at least a change of synopsis. As the high above Russia will most likely be pushed away, the low pressure areas could finally take another course (toward mainland Europe). However, it will take some time before the result of this change in weather synopsis will be clear. 

 

EDIT: one thing that was also interesting is that the ECMWF develops the Finland low up to 974 mb toward Siberia (only visible on NH charts, but I won't post them because the post would then become slightly too long. The result of this is deep cold flowing out over the eastern part of Scandinavia. If, and a big if, a Scandinavian high would develop, it could bring very cold uppers toward NW Europe. The GFS doesn't show the low to be as deep as the ECMWF.

 

Also, as Nick Sussex noted in the post below, the main fate for us will be upstream, where the PV is the main player.

 

Source:

http://www.wetterzentrale.de/topkarten/fsavneur.html

Edited January 4, 2014 by Vorticity0123

[legritter]

Hi all, forgive my total lack of knowledge here, but just wondering about the Ice storm hitting NY and Canada. What is the possibility of that weather coming our way - even as more rain? Doesn't it often follow that what they get we get a week later - or is that an old wives tale??Many thanks, Woody

no its not an old wives tail .if we are in a cold pattern say high pressure somewhere to our north and its mainly dry what happens is low pressure exiting the states moves across the atlantic and can bring snow if it moves close to the uk ,but it does not happen very often ,you need the right weather patterns especially the jet aligned right .Im feeling a bit more upbeat tonight lets hope something is a lurking out there perhaps at day 10/11 .cheers .just would add that i meant weather system rather than any wintry element making it across the atlantic ,cheers . Edited January 4, 2014 by J10

[nick sussex]

Very pleased with tonights outputs, even though the ECM doesn't deliver a deep cold easterly it will be much colder than recently. Theres still also a chance that it could develop more favourably.

 

Earlier the easterly carrot is still dangled because of the fine margins that could tip the balance that way, I think we have to look upstream once again to see how the pattern there will effect the amplification in the mid Atlantic because with a bit more sharpness upstream we could get a better kick north of the high.

[chionomaniac]

I have to say C with all respect, people have been following the Ens since late autumn and they have offered no more in the way of guidance than simply following the operational’s and using a little knowledge and some common sense, they chop, change and trend this way and that in much the same way, which is not surprising as they come from the same data, just tweaked. If over the years I had a tenner for every time this thread had been advised that the Ens would cast some light on the way ahead, only for the Ens to show nothing of the sort, I'd have accumulated a large pile of cash by now. The main problem for all modelling, is that the starting data is constantly changing, the Ens are supposed to help with that fact, but what you end up with is Bertie Bots every flavour of jelly bean, with little idea of which one isn’t poisoned, thus people on this thread just go with whatever most suits their preference, usually cold in winter because that’s what most of us are looking for. In terms of the tweaking there must be a set criteria for the way each perturbation is set, so with every new run with its change in data a corresponding pre-set change must be made to each ensemble run, therefore an ensemble spread can only be of real use when analysing the run that they were derived from, trying to put them in the context of several runs over several days in an attempt to look for trends is fraught with even more problems than attempting to find a trend in just the operational’s, this is because the greater number of perturbations the greater spread of possible outcomes, in other words spotting the correct trend can become like looking for a needle in a haystack, especially given that the chaotic nature of climate means that even when something looks to have wide support it still has a massive chance of not being the correct trend, in other words you may have a good cluster of members supporting a similar evolution but a single member with no support could conceivably be the correct call. I hope this make sense it does to me at least LOL

I guess that is when a little experience comes in handy as well. I would say that when the ensemble trends in the same direction that the MJO, GWO and strat data point to then one will have a far better chance of picking out that needle in a haystack. Also you will have a far better chance of picking a trend looking at all of the ensembles over all the output over a number of runs, rather than just looking at the deterministic runs. I guess that you are trying to say that the ensembles can occasionally lead you up a garden path, but more often than not they will spot a trend especially if one looks at the cumulative anomalies set over a number of days.