Model Output Discussion

[Tom D]

All I can say is that neither the GFS 6z or the ECM 00z go with the horror show at t+96 that is the UKMO.

http://91.121.94.83/modeles/gfs/run/gfs-0-90.png?6 t+90 GFS

t+96 ECM

t+96 UKMO

Big frontal snow event for the midlands shown on the 06z, two in fact, one back edge on Tuesday, one front edge on Thursday. Scotland also seeing some snow again at some point with this set up. Hard to pin-point accurately though with the GFS precip charts AND the fact it goes against the UKMO.

Edited January 31, 2010 by Tommyd1258

[cooling climate]

Looking at the 06z t96 GFS chart and things are very finally balanced. It really could

go either way or as I said earlier the easterly just being delayed by a couple of days.

This is not wishful thinking by the way.

[Snowly does it]

T102 and the flow is SErly trending ESErly as the LP hints at undercut, however the LP system coming off the Eastern seaboard is going to interract and I fancy this will not be in favour of cold..... let's see

[The PIT]

Gosh what a change in those ECM ensembles...I suspect the London ones will look even milder when they come out in a bit. I'd love to be a fly on the wall of Met Office HQ and to hear their discussions this morning as even they were suggesting a cold easterly developing later next week even though their very own model didn't look favourable for that set up developing.

This morning they weren't getting milder as the week goes on was the comment which sure I checked the models again expecting a track by the gfs which it has.

[conor123]

The amount of gloom on this board today is slightly ridiculous considering the winter weve had so far.

Both the ECM 00z and the GFS 06z would give snow events somewhere in the UK, and it really wouldn't take much to see a major snow event at some point between Wednesday and Friday.

[TEITS]

What is slightly ironic, is that its the trough which moved into Scandinavia to bring us the northerly which ultimately is providing the brick wall preventing the easterly progressing westwards.

Very much agree and fair play to GP because he said the models were too progressive with the scandi trough.

This has prevented the block moving futher W and ultimately open us to attack from the Atlantic.

Still looking at the 06Z and its nothing like the UKMO at +120. Maybe the drama hasn't finished just yet. Fully agree with Tamara and I have to confess with being erractic with my posts of late.

[chionomaniac]

As ever in these situations I am never sure whether it is the models that overreact or the members.

Has anyone actually looked at the actual patterns being shown by the models today ??

Amongst the melee of rubbish that was seemingly posted after I left here last night, I said on parting that the ECM and the GFS were both showing a -NAO pattern and a -AO pattern. The difference was that the GFS was going to undercut the block and the ECM was going to place a deep trough in the mid western atlantic slightly north of the Azores area whilst pressure rose over Greenland and Canada.

What we see again this morning is the same -NAO/AO pattern but what has happened is the GFS has fallen in line with the ECM idea of the variation on the -AO pattern. Of course in terms of the actual weather that results from it we see mild south westerlies instead of the cold easterlies - so it seems like the models have done a huge flip.

In fact, to my eyes anyway, they seem to followed have GP's script of heights lifting out from Siberia and moving to Canada/western Greenland. End result is that the blocking is too far south west!, and the -NAO too far west for any undercut to take place. Instead we see a down stream ridge over europe. Hence the mild tropical maritime aistream currently suggested.

This situation is still very liable to change over the coming few days, and needs to watched closely.

Whilst a big freeze was never guaranteed, an extended blowtorch is not guaranteed either.

Can't people ever stop going to extremes and just calm down on here!?

Oh, I forgot the UKMO. As far as I can see it has actually overracted the most to the signal in terms of taking the energy in the atlantic too far east. The GFS and the ECM have met in the middle and the UKMO is still out on a limb in this respect.

A good post Tamara. You have just saved me 10 mins typing the same thing. It is very frustrating to see a -NAO and -AO forecast but not being able to cash in due to the strength, orientation and positioning of the block. I still don't think we will get a mild Feb. more towards average with some cold outbreaks. March could possibly be blocked but we will get a better idea mid Feb.

[KTtom]

Well a bit of an improvement from the 00Z by the GFS, Wednesday to Friday temps just above freezing over most of the country with fronts making painfully slow progrss NE'wards. It'll be interesting to see what Countryfile make of this. This mornings forecaster did hint at a week of mild/cold battle.

[Totoro]

Very much agree and fair play to GP because he said the models were too progressive with the scandi trough.

This has prevented the block moving futher W and ultimately open us to attack from the Atlantic.

Still looking at the 06Z and its nothing like the UKMO at +120. Maybe the drama hasn't finished just yet. Fully agree with Tamara and I have to confess with being erractic with my posts of late.

Oh I don't know, I think you've done very well, unlike the flip flopping models.

I still wouldn't say that this is cut and dried either way - even 3 days ahead the model outputs vary greatly, even from run to run on the same model - I have a sneaky hunch that the Atlantic will 'win', but it also wouldn't surprise me if we end up with kind kind of easterly or south easterly. Fence-sitting seems to be the preferred option right now.

[Lewis]

I second what Tommyd says,

just looking at the 06z and it's sticking to it's guns, out too +129 now, and it's showing an E/SE trying to push through as the LP swings around.

I think we should not long any further than this, the UKMO may change, after all it's the models that have human input, so why can it not be opinionated? With a scatter of ensembles going for milder outcomes, and a fair few (mainly non euro's in medium range showing the cold trend continuing from now).

So i say we wait

[Guest North Sea Snow Convection]

Very much agree and fair play to GP because he said the models were too progressive with the scandi trough.

This has prevented the block moving futher W and ultimately open us to attack from the Atlantic.

Still looking at the 06Z and its nothing like the UKMO at +120. Maybe the drama hasn't finished just yet. Fully agree with Tamara and I have to confess with being erractic with my posts of late.

Morning Dave. I wouldn't, personally, include you in that bracket at all. Looking at possibilities for a cold easterly is fine, but also tempering it with caution that anything can still also happen. As far as I could see, you were doing both of those.

No, the changes almost certainly haven't finished yet. It is not as if we are launching from a -AO pattern into a +AO pattern. If that was the case then it would be a long way back to a cold pattern. But it isn't the case at all.

Everything still there to watch with an open mind

Edited January 31, 2010 by North Sea Snow Convection

[Snowly does it]

GFS 06z shows a cold week with snow threat the further East and North you are, the -5 850s are around and about for much of the period with -10s approaching later in the week. However, the LP system I mentioned earlier by T138 is bombing and riding the HP ridge as the jet buckles towards the SW of the UK and this (for this run) is, I think, where milder conditions will win through

[Totoro]

Now I know that these charts aren't very accurate, but interesting to see the prognosis for snow on a number of days:

http://91.121.94.83/modeles/gfs/run/gfs-2-60.png?6

http://91.121.94.83/modeles/gfs/run/gfs-2-84.png?6

http://91.121.94.83/modeles/gfs/run/gfs-2-108.png?6

Edited January 31, 2010 by Totoro

[Guest North Sea Snow Convection]

A good post Tamara. You have just saved me 10 mins typing the same thing. It is very frustrating to see a -NAO and -AO forecast but not being able to cash in due to the strength, orientation and positioning of the block. I still don't think we will get a mild Feb. more towards average with some cold outbreaks. March could possibly be blocked but we will get a better idea mid Feb.

Hi - yes you might well be right there.

GFS 06z shows that the models are not completely sure yet about jet energy. The ensembles are sheep just as much as the operationals. GP suggested very poor model performance so we could just as easily see full support for another freeze up in 24 hrs! Very volatile and I think that this is going to continue a while yet

The models often overreact to new signal and then start to reign back in. This latest GFS output shows that events later this week are subject to huge uncertainty. And that is an understatement.

Expect the unexpected I say!

Edited January 31, 2010 by North Sea Snow Convection

[Tom D]

I second what Tommyd says,

just looking at the 06z and it's sticking to it's guns, out too +129 now, and it's showing an E/SE trying to push through as the LP swings around.

I think we should not long any further than this, the UKMO may change, after all it's the models that have human input, so why can it not be opinionated? With a scatter of ensembles going for milder outcomes, and a fair few (mainly non euro's in medium range showing the cold trend continuing from now).

So i say we wait

I don't think the UKMO has human input let alone bias, the FAX charts are produced by professional forecasters at the Met Office who look at all the data they can and produce what they think is the most likely outcome. As there was so much disagreement at a short range between the 'big 3' if you like, they stuck mostly with their own model and fair play.

It isn't in the best interests of the Met Office to produce biased-to-mild charts especially after what their long term forecasts have predicted in the past 8 months. They will understand this situation better than 99.9% of people on this forum so to suggest that they are opinionated it a bit of a hollow statement.

Anyway - despite the GFS 00z/06z runs not looking so good as last night for a SE flow early on, it at least doesn't go with the UKMO early on (although with the 6z it gets fairly mild later ). Someone here last night got it right IMO - not much difference in the synoptics can lead to massive changes in weather down the line.

Edited January 31, 2010 by Tommyd1258

[The Weather Dragon]

GFS falling into line with ECM and METO - the easterly is dead and buried now - a lesson learned reg FI charts - I remember reading a few years ago on here not to go beyond 144 hours when looking at models - Excellent advice.

Edited January 31, 2010 by Jonathan Evans

[john mac]

Hi - yes you might well be right there.

GFS 06z shows that the models are not completely sure yet about jet energy. The ensembles are sheep just as much as the operationals. GP suggested very poor model performance so we could just as easily see full support for another freeze up in 24 hrs! Very volatile and I think that this is going to continue a while yet

The models often overreact to new signal and then start to reign back in. This latest GFS output shows that events later this week are subject to huge uncertainty. And that is an understatement.

Expect the unexpected I say!

Morning Tamara

I agree with you there IMO the 6z is definately less progressive, although we dont get the easterly, it is by no means mild either. I still believe that we shouldnt look too far ahead as there is alot of chopping and changing going on with the models still.

[Frosty.]

GFS 06z shows a cold week with snow threat the further East and North you are, the -5 850s are around and about for much of the period with -10s approaching later in the week. However, the LP system I mentioned earlier by T138 is bombing and riding the HP ridge as the jet buckles towards the SW of the UK and this (for this run) is, I think, where milder conditions will win through

Cold air fighting back on the 6z but then I thought the gfs 00z was looking cold for the next week, especially ooop north with frost and snow, of course that's no consolation for members in the south as temps return to near average but I thought some members from scotland might have commented on this

[swilliam]

A pretty good run for next week from the GFS. Cold for most of the week and plenty of chances for snow - especially the further North you are. A lot of the snow events could be quite marginal though. It is not until the deep low approaches next weekend that the mild air makes major inroads and as we know that is FI. It will be interesting to see whether the UKMO go with their model or the ECM/GFS for the forecast for the week ahead.

[andymusic]

GFS 06z is still showing my area from tuesday night onwards to be cold and potentially snowy till friday - so still all to play for yet!

[La Bise]

I still got the 8th marked down in my calendar as a possible turning point day, I'm no fan of synchronicity but it's a straw to clutch at in these dark hours for cold lovers...

[BLAST FROM THE PAST]

I refer to my earlier post re look no further for certainty than the ECM chart I posted. Like for cold forecast, any backslapping re mild outcome now nailed should hold on. 06z perfect example of what hasn't happened yet. With the ECM arctic ridge there is no clear sign on how far NE energy will get...and I still say as I did a few days ago the UKMO sends a way to far NE......lets see what develops tomorrow shall we. Look N and NW...that is where the block will build.

I suspect that next 36hrs will be fascinating model watching...and I'll hint at some sudden changes too.

BFTP

Edited January 31, 2010 by BLAST FROM THE PAST

[Snowstorm1]

Cold air fighting back on the 6z but then I thought the gfs 00z was looking cold for the next week, especially ooop north with frost and snow, of course that's no consolation for members in the south as temps return to near average but I thought some members from scotland might have commented on this

Dont forget Ne England on this run were in the cold air much longer Wouldnt it be typical if tonight all models backtrack again towards a continental feed and tbh i wouldnt back against it Btw COME ON MURRAY!

[The Weather Dragon]

look no further than 144

[Guest North Sea Snow Convection]

Morning Tamara

I agree with you there IMO the 6z is definately less progressive, although we dont get the easterly, it is by no means mild either. I still believe that we shouldnt look too far ahead as there is alot of chopping and changing going on with the models still.

Hello John,

In this situation of model chaos, it is a virtually impossible task to try and give a further outlook by the METO. It should just state 'very low confidence and subject to rapid change' !!

There have been lots of comments and myths posted about the fax charts I have seen. Reading into why they follow one model or another, cold or mild. Atm the significance of them showing, say just purely for illustration of the point, a chart akin to the UKMO for t120, means nothing at all atm as these could well be re drawn and changed so many times over the next day or two!

Edited January 31, 2010 by North Sea Snow Convection