Winter Model Discussion 18Z 12/2/13 onwards.

[Panayiotis]

Finally on the GFS at 114hrs we have the cumulonimbus shaped heights to the north!

Edited February 14, 2013 by Panayiotis

[Mair Snaw]

Met O answer - NAE retirement due around end of year.

GM will take over at 17km resolution (i.e., now finer resolution) - it now has capacity for 4km embedded resolution anywhere in the world, as being used in Middle East for military etc currently.

UK4 and Euro4km models already make NAE capacity effectively 'out-done'.

MOGREPS-R new ensembles run at 2.2 km resolution and also surpass NAE.

Thus - in simple terms - the GM is being upgraded to run at 17km resolution with various high-res products embedded, so NAE is past-purpose given vastly improved computing power for regional stuff and ditto existing 4km European f'cast capacity (expandable worldwide).

Re Doppler - most of network now doppler already. No immediate plans to make public but may follow at some stage down the line.

Cheers

Cracking stuff Ian and once again many thanks to you and the guys at the meto.

[SMU]

http://modeles.meteociel.fr/modeles/nogaps/runs/2013021418/nogaps-0-132.png?14-23

NOGAPS now inline- thats every model on board bar the GFS-

ALL>GFS.

PWNT

[Ice Day]

Great ECM and UKMO, but once again the pub run is producing uninspiring stuff. Still, it's a complete shambles at the moment so can be safely discarded (until it's showing snowmageddon at 384 when we can once again sing its praises!)

[Cloud 10]

In case anyone is wondering the gfs 18z is rather underwhelming so far.

[Panayiotis]

http://modeles.meteo...0-132.png?14-23

NOGAPS now inline- thats every model on board bar the GFS-

ALL>GFS.

PWNT

Yes it sure is but should we be using it now as it has been replaced for the NAVGEM?

[fergieweather]

Just to advise UKMO have again just modified GM at t+132 - 144 to again retard cold air advance and thus greatly reduce wintry shower threat at that juncture. Rationale to follow later.

[Captain Shortwave]

http://modeles.meteo...0-132.png?14-23

NOGAPS now inline- thats every model on board bar the GFS-

ALL>GFS.

PWNT

Can't believe I have to use this again for a GFS 18z, great inter run consistency, shame it has a 99.9% chance of being wrong up to t144

[Mair Snaw]

In case anyone is wondering the gfs 18z is rather underwhelming so far.

has the GFS been anything other than underwhelming all winter? it is fast becoming the joke model that is run to just make the likes of us laugh as we wait the ukmo and ecm runs....

[Ice Day]

In case anyone is wondering the gfs 18z is rather underwhelming so far.

And no movement towards the Euro's as far as I can see. If anything it's a downgrade from the 12z's.

[Bristawl Si]

Just to advise UKMO have again just modified GM at t+132 - 144 to again retard cold air advance and thus greatly reduce wintry shower threat at that juncture. Rationale to follow later.

A sobering post Ian to temper the enthusiasm from the model output.

[Ali1977]

Heres me hoping for a proper Siberian blast before Spring starts...Ian just scuppered that a little, if it is proved correct!!!

[Cloud 10]

New fax chart for Monday has a cold continental airflow across the UK.

[Jason M]

A sobering post Ian to temper the enthusiasm from the model output.

Not a massive issue of itself. Just slows things a bit, which looking at METO charts isnt a shock really as it did look a bit on the quick side when compared to other models.

GFS remains a real concern given that the seeds are sown early. I know some might think GFS poor, but i'd be very wary of ignoring any of the main models inside the 120 hour window.

Jason

Edit - GFS on board albeit much more slowly

Edited February 14, 2013 by Jason M

[Ice Day]

And finally we're getting somewhere at 240hrs. Still, given it seems to be completely out of whack at 96hrs this is not to be trusted - looks nice though!

Edited February 14, 2013 by Ice Day

[Met4Cast]

Well if the Met Office are using NAVGEM instead of the GFS, maybe we should start paying attention to this new model too.

T144

Seems to fit in well with the reduced snow risk

Model can be viewed here

http://www.meteociel...geme_cartes.php

Edited February 14, 2013 by Daniel Smith

[Tamara]

A sobering post Ian to temper the enthusiasm from the model output.

Just a few days ago the official METO consensus rationale was for a SSE airstream and average to slightly below average conditions with suggestions of the greatest rainfall being in NW UK (suggesting attempted atlantic incursions over any High pressure area to the NE. No perceived threat of any wintry weather at all.

As we know that has changed, and has been led by the raw ECM and UKMO and any attempted breakdown, if it comes, is via an undercut and not any eastward pressure on the blocking..

If the latest continued conservative UKMET thoughts are true then we should expect an imminent tempering of the raw UKMO and ECM output (maybe even as early as tomorrow morning?) Otherwise, on the other hand, it is quite feasible that the the more wintry outlook/trend continues to gain favour over the current official and more cautious lines...We will see .

Edited February 14, 2013 by Tamara Road

[SnowObsessor90]

And finally we're getting somewhere at 240hrs. Still, given it seems to be completely out of whack at 96hrs this is not to be trusted - looks nice though!

Well other than that it seems to be mostly dry and cold/cool with us under the influence of high pressure, as you say it is most likely to be wrong due to the differences in the earlier time frames but still I'd take that over another eventual Atlantic breakdown.

Edited February 14, 2013 by SnowObsessor90

[bradymk]

Well if the Met Office are using NAVGEM instead of the GFS, maybe we should start paying attention to this new model too.

T144

Seems to fit in well with the reduced snow risk

Model can be viewed here

http://www.meteociel...geme_cartes.php

Sorry Daniel, been away all night, have the MetO said that they are using the NAVGEM model?

Basically, GFS still pretty underwhelming, poor performance at the moment. UKMO, GEM also with ECM. Another solid run from ECM with just variation of the same theme with the det and ens in good agreement with E/SE flow and also now showing a slider event, a common feature of this winter. Where the upper cold pool locates itself and length of cold still open to question but expected at this range. The uptick of milder members at the end of EC ens also not unusual at this range, would not worry about that at this stage. The 12z ECM did back away from a Greenland high that had been showing on previous runs. Hopefully it will return in its 00z run but as we have seen this winter, it is not vital and we can still get some great cold and snowy synoptics without it.

Edited February 14, 2013 by bradythemole

[Chris W]

18z GFS playing about with shortwaves vs heights going north/west but gets there with the easterly eventually, before an advance of cold from the north later. Don't see mild in the mid-late stages of this run.

[Panayiotis]

Its been 24hrs since my post yesterday (http://forum.netweat...ost__p__2608909) about what the models were showing at 120hrs, so lets see how the models are looking at 96hrs:

So above we have the GFS,ECM,UKMO,GEM,NAVGEM,BOM,CMA,CPTEC,CFS and the JMA. You can see that there are 3 models which show something different from the other models and that is the GFS and CPTEC. They are different as they dont show cumulonimbus shaped heights to the north and both fail to move the energy SE and instead they send it over STILL! The JMA doesnt show the heights that the

ECM,UKMO etc shows at this timeframe but manages it 108hrs and therefore the low goes under.

I think (as well as others) the GFS and CPTEC is wrong and will change tomorrow, to me the foundations are set at 4 days away and as long as the foundations approach us, the cold will follow. As it stands its 8-2 compared to 6-4 yesterday for colder weather.

Another interesting day of models watching to come tomorrow!

Edited February 14, 2013 by Panayiotis

[Guest bjaykent]

120 fax chart for Tuesday showing cold easterly flow across UK but with Low further east presumably as mentioned by Ian F earlier.

[Jason M]

Well the GEFS are pretty tasty tbh. Some great runs in there.

Good end to the evening I'd say.

Jason

[fergieweather]

Just to advise UKMO have again just modified GM at t+132 - 144 to again retard cold air advance and thus greatly reduce wintry shower threat at that juncture. Rationale to follow later.

Ok, so to offer the rationale:

UKMO-GM is rather an outlier versus other deterministic models: i.e. it is much quicker with the cold advection by mid-week. MOGREPS continues to show wide spread of the sub-528DAM air as per yesterday's output and given such limited support for this extent and rapidity of CAA, the 12z GM was modified (as per yesterday) to slow this process and keep the whole pattern further NE. One net result is to hold higher WBFL's over the UK for longer and albeit tephigrams suggest light showers by Weds in easternmost areas, their wintry component is greatly reduced versus the more widespread signal progged in the raw output.

Hope this explains! In summary: little change in thoughts from Exeter out to t+144 but a greater imponderable is actually proximity of the frontal zone near the SW by Monday, which is a more problematic part of the MRF.

[Jason M]

Ok, so to offer the rationale:

UKMO-GM is rather an outlier versus other deterministic models: i.e. it is much quicker with the cold advection by mid-week. MOGREPS continues to show wide spread of the sub-528DAM air as per yesterday's output and given such limited support for this extent and rapidity of CAA, the 12z GM was modified (as per yesterday) to slow this process and keep the whole pattern further NE. One net result is to hold higher WBFL's over the UK for longer and albeit tephigrams suggest light showers by Weds in easternmost areas, their wintry component is greatly reduced versus the more widespread signal progged in the raw output.

Hope this explains! In summary: little change in thoughts from Exeter out to t+144 but a greater imponderable is actually proximity of the frontal zone near the SW by Monday, which is a more problematic part of the MRF.

Looking at GEFS this evening I've a hunch that your in for a busy couple of weeks. GFS opp looks one of the warmer runs at first sight.

Jason