Model Discussion Thread - January 13th

[mountain shadow]

How can anyone say that this is not a good run? It brings in the colder air earlier, almost the whole of the Uk under cold uppers by Thursday and staying there until the end of the run. ECM is the top model and has been consistent now for over 4 days however some guys in America favour the GFS so expect disapointment tomorrow.

Edited January 13, 2012 by mountain shadow

[Tim Bland]

If its not sorted by Sunday we can go back to the good old days and just watch the country file forecast!

Although I think the Gfs will backtrack part of me hopes it doesn't. Reason being we have great charts to analyse from it and it goes out to 300+ hrs. If it is completely wrong I don't think I'll trust it again

Edited January 13, 2012 by Tim Bland

[Cheshire Freeze]

Well I think most of us were expecting the Atlantic to barrel through on the ECM at around T144 and its a questionable evolution, certainly I would have ruled it out prior to 2008.

The stand-off goes on, the US guys place the greatest faith in the GFS 12z and not one of its members could be described as remotely like the ECM at T168, so maybe the ECM ensembles will show this run to be on the cold side. It's bizarre.

At the minute Ian it's pretty much on its own in regards to the ejection of that low at 144 hours.....of course this doesn't mean it's incorrect

[kev238]

It will be crucial to see the way the ukmo model handles things over the weekend. The nineteenth seems to be the key day so will

Be well within the range of that model by Sunday!

For me, getting a cold chart on the ukmo is key before I think about getting my sledge out. However, ECM looks great, though it is difficult to pick out snow opportunties from the charts as they are quite flabby!

[Bobby]

By the way the GFS is currently in 4th place at +144 for accuracy, with ECM top, UKMO 2nd and GEM 3rd. I always think far too much weight is given to the GFS considering there are more accurate models available.

[chionomaniac]

Well I think most of us were expecting the Atlantic to barrel through on the ECM at around T144 and its a questionable evolution, certainly I would have ruled it out prior to 2008.

The stand-off goes on, the US guys place the greatest faith in the GFS 12z and not one of its members could be described as remotely like the ECM at T168, so maybe the ECM ensembles will show this run to be on the cold side. It's bizarre.

Ian,

In my experience any respected US guys don't trust the GFS as far as they could throw it. If you have found the two guys that love it, then well done, but unless you are able to tell us who they are and show us their postings, then I would respectfully ask that you keep them out of this model thread.

After all they could be the Ian Browns of America and not a true representation.

Cheers

c

[nick sussex]

I think overall a small step forward to a colder solution, this is taking into account all the model output and factoring in the earlier discussions from NOAA regarding the progressive nature of the GFS.

However the transition from 168hrs to 192 hrs on the ECM relies on upstream events too far out to be sure of how much forcing is placed on that trough to sink.

So in terms of some colder weather yes a decent chance, but depth of cold and longevity remains uncertain.

In those discussions you should factor these areas into how the models could develop:

IN THIS PATTERN...PREFER A LESS PROGRESSIVE LOW/FRONTAL PUSH

ACROSS THE CENTRAL THEN ERN US EARLY TO MID NEXT WEEK THAN THE 00

UTC GFS/GEFS...MORE IN LINE WITH ECMWF ENSEMBLES THAT ARE NOT

QUITE AS SLOW AS THE 00 UTC AND NOW 12 UTC ECMWF. THE 12 UTC GFS

HAS TRENDED TOWARD THIS SOLUTION WHOSE SUPPORTING TROUGH ALOFT

STILL HAS DECENT AMPLITUDE.

The slower the progression of systems out of the USA the better, also the more amplified improves the chances of downstream the trough heading se.

LATE NEXT WEEK...ECMWF RUN TO RUN CONTINUITY ISSUES AND

OVER-DEVELOPMENT POTENTIAL WITH ENERGY MOVING ACROSS SW CANADA/NW

US BORDER AND SUBSEQUENT DOWNSTREAM DEEP LOW CYCLOGENESIS CENTERED

OVER ND BECOME INCREASINGLY EVIDENT. LIMITED DEVELOPMENT AS PER

THE GFS/GEFS AND ECMWF ENSEMBLES SEEMS MORE REASONABLE GIVEN

FLATTENED FLOW AND UNCERTAINTY WITH NEEDED INFLUX OF BOTH NRN AND

SRN STREAM ENERGIES FOR OCCURANCE. THE 12 UTC ECMWF HAS NOW

STRONGLY BACKED AWAY FROM ITS 00 UTC RUN ND LOW.

The low they are talking about effects the movement of the PV, which effects that small high to the north, remember you need something to help force that troughing south to get into that much colder east/ne flow.

So in terms of the pattern upto 168hrs I'd say the ECM looks fine on this especially as this has the support from the UKMO at 144hrs, this wobbled earlier today but thankfully has moved back, although the GFS is reluctant to join the Euros it has made some adjustment.

I would look no further than 168hrs and keep an eye on events towards Newfoundland in future output, for arguments sake lets say the ECM did verify it is a good example of how you can get cold without the need for some big block to the north, as long as the PV is far enough to the nw and you have energy running into Iberia.

Given that the GFS seems to be overly progressive within 144hrs and the other outputs are slower I'd expect to see it inch towards the ECM on its 18hrs run, I doubt it will go all the way there in one run though.

An initial nw flow seems a reasonable call but to get from there to the east/ne still needs to jump a few hurdles.

[Paul]

After some differing opinions on the differences between last night and this evening on the ECM, I thought it may be helpful to compare the latter parts of the ECM run from last night to tonight..

Starting with tonight's 168 hour forecast (compared with yesterday's 192), the broad pattern is similar, although there are some changes in the positioning of low pressure systems close by to the UK. It's colder tonight than yesterday.

Today's charts on the left.

The 192 hour chart from tonight (comparing to yesterday's 216) and again we have some agreement, some disagreement. The cold air is again further west than yesterday.

Finally, tonight's 216 hour forecast (yesterday's 240). It's fairly similar, obviously some change in the detail and the setup but reasonable agreement both in setup and conditions on the ground.

I'm going to try to setup an option to compare to yesterday on the ECM viewer this weekend (it already has the option to compare to the previous run - just click the prev button)

http://www.netweathe...ction=ecm;sess=

[January Snowstorm]

Models starting to gang up on the gfs now tonight.

If the ECM does win this battle, and remember it would be along what GP was expecting, it will have scored a big win over the gfs

[Stuie]

I posted yesterday about the jet stream by the GFS but no response I think. The GFS has the stream flying into the UK from the NW at 162/168. It has some speed behind it. How much does the jet affect things? What does it pull along with it?

[Matty M]

I think the ECM Ensembles will be a big player tonight.

We will get to see the 168hr timestamps around 830pm.

If they can hold consistency the ECM is looking good, show a 50.50 split, i would begin to get worried.

Edited January 13, 2012 by Matty M

[Frosty.]

I'm very pleased with tonights ecm, I was concerned we would have seen a climbdown to something more moderated but it hasn't happened, this run also has the support of other models so it's not on it's own and we have seen the gfs 12z make tentative movement towards the ecm so we are still on track for a cold snap/spell with snow potential from late next week, the big question is how long will it last but that will remain unanswered for a while yet.. I would say the odds on a cold unsettled spell developing are currently good to very good.

[kev238]

By the way the GFS is currently in 4th place at +144 for accuracy, with ECM top, UKMO 2nd and GEM 3rd. I always think far too much weight is given to the GFS considering there are more accurate models available.

Well you did use the word currently so agreed it is fourth. However, look back through the graph for the northern hemisphere and it is not simply a case of the gfs being fourth. Sometimes it is neck and neck with other models, sometime almost ahead, but at times prone to getting it badly wrong as evidenced by the obvious dips!

[Cheshire Freeze]

The GFS is usually my model of choice and for that reason I can't ignore its output today. However, IF and a big if at that, the ECM wins this battle I think I may have to invest more time in the model.....it's just a shame that the powers that be won't allow greater access to its ensembles etc.

[snowking]

Or the ECM model will tmw become a joker who loses its status as a model of choice in this window of Winter...I really do expect the GFS 18z to stick to its guns barrell the PV...Flatten the ridge and come out tops...The ECM 00 will carry on with a flatter ridge and we will see tmw.

Apologies Paul re the timescale bickering.

Regards

Regards

Whilst I can't necessarily agree with your view on the ECM flattening the ridge, I'm glad we have some people in this thread looking at the flip side of things to provide a little bit of balance

I think the overwhelming message that needs to be put out here is you cannot predict the models! It's no good saying 'the GFS will win out' or 'the ECMWF will back down at 0z' - so for any newer members getting confused anybody trying to predict what the next model run will do simply ignore it, we have no idea of how each run will evolve before its programmed.

RE: talk of the JMA - it verifies as well as the GFS at the moment out to days 5/6, so it's got just as much chance of being right as the GFS has at the moment, which probably just about sums up the picture at the moment - near impossible to tell!

SK

[Paul]

I posted yesterday about the jet stream by the GFS but no response I think. The GFS has the stream flying into the UK from the NW at 162/168. It has some speed behind it. How much does the jet affect things? What does it pull along with it?

You can find a lot of info about the jet in our tutorial here:

http://www.netweather.tv/index.cgi?action=jetstream-tutorial;sess=

In short though, the jet is very important.

[chionomaniac]

Models starting to gang up on the gfs now tonight.

If the ECM does win this battle, and remember it would be along what GP was expecting, it will have scored a big win over the gfs

JS, it's not a matter of winning or losing. It is a matter of the model calculations finding the correct solution and forecast. No more, no less.

[Cheshire Freeze]

Well you did use the word currently so agreed it is fourth. However, look back through the graph for the northern hemisphere and it is not simply a case of the gfs being fourth. Sometimes it is neck and neck with other models, sometime almost ahead, but at times prone to getting it badly wrong as evidenced by the obvious dips!

I have no problems with what you are saying but what I can't get my head around and a point that is worrying me is how can a whole ensemble suite be wrong? You would assume that at least one or two ensembles would show the ECM evolution but they don't. I don't get it.

[Duane S.]

Ian,

In my experience any respected US guys don't trust the GFS as far as they could throw it. If you have found the two guys that love it, then well done, but unless you are able to tell us who they are and show us their postings, then I would respectfully ask that you keep them out of this model thread.

After all they could be the Ian Browns of America and not a true representation.

Cheers

c

Agreed, if Chuck and Cody Brown reckon the GFS is on the button then we at least need to see their/your reasoning behind it (Ian). Who knows they may be on to something but throw us a bone?!

Edited January 13, 2012 by s4lancia

[Great Plum]

Agreed, if Chuck and Cody Brown reckon the GFS is on the button then we at least need to see their/your reasoning behind it (Ian). Who knows they may be on to something but throw us a bone?!

Indeed... It will also be interesting to find out what NOAA say, who are, of course, the professionals...

[Brum Watcher]

after reading the above posts it seems as though GEM, NOGAPS, JMA all trending tiwards the ECM. and even the GFS needle pickingly tried. ECM has only increased the potential throughout the run aswell. MEGA 18z on the cards me think. The Faxes later also.

[Harsh Climate]

GFS v ECM who will win??

For me over the last week or so the gfs has showed pretty much every evolution under the sun! Whereas the ECM over the last few days has been consistantly showing a similar picture.

The difference is mainly between 168h-192h, the ECM has the detached area of PV pull away south east of us with pressure building in it's place (between the east of greenland and the west of scandinavia.) This is a pretty nice place for any developing high pressure to set-up shop, not strong enough for our only snow fall to come from a direct easterly breeze in the form of showers, but weak enough to allow depressions/troughs from the west/south/north :o to attack, with the standard chance of snow showers blowing in from the east.

Look at the GFS:

The PV from the north never gets south of us, not allowing high pressure to take it's place (gving us good block) and with that milder air allways likely to break through over the azores high from eventually the northwest/west. Not good really and would only give snow to scottish hills from time to time, as I'd expect that to pan out from there <_< .

I said days ago that in terms of blocking the ECM is the main player and If I had to stick my neck an the line I would back the ECM, not but because it shows what I want to see but because it has

• Best verification stats
  
• has been consistant regarding what it thinks the outcome will be
  
• The gfs has been ridiclously all over the place.
  

Although I expect the ECM to win I would expect perhaps a watered down version of what it's currently showing. from 168h, I think we will have wintry showers eventually pushing into eastern areas, progresively turning to snow as the colder uppers push in from the east, but with quite light winds and no severe core of cold air coming in I think snow accumulations would be small, then I think as little depressions and troughs attack from all sides I think there will be spells of quite widespread snowfall, but at this stage distribution and amounts are uknown. But we would be in a period of great POTENTIAL heading into Februrary

Also if we could get the NAO to -2 or below and the AO to -3 or below I think februrary could be a month for the archives

http://www.cpc.ncep....a/nao.sprd2.gif

Edited January 13, 2012 by Harsh Climate

[nick sussex]

Agreed, if Chuck and Cody Brown reckon the GFS is on the button then we at least need to see their/your reasoning behind it (Ian). Who knows they may be on to something but throw us a bone?!

Lol!

I think the GFS is a good model and is very generous with its info, but I read those extended forecast NOAA discussions every evening in the winter and the majority of the time they use the GEFS and ECM ensemble means or the ECM operational run upto day 5 then switch to its ensemble mean upto day 7, the times they use just the GFS operational is very much in the minority.

In the later ones which include the NOAA maps thats often a blend of the GEFS/ECM ensemble means, at the end of the day we only have the verification stats to go on and the facts speak for themselves, the ECM is the best global model upto 144hrs.

Whatever the US guys say about the GFS they can't argue with facts, their homegrown model is generally in 3rd or 4th place at 144hrs.

Of course models all go through bad periods, could the ECM be wrong well of course anythings possible but whilst the UKMO backs the ECM its very unlikely.

[Cloud 10]

Ian,

In my experience any respected US guys don't trust the GFS as far as they could throw it. If you have found the two guys that love it, then well done, but unless you are able to tell us who they are and show us their postings, then I would respectfully ask that you keep them out of this model thread.

After all they could be the Ian Browns of America and not a true representation.

Cheers

c

I think this is them!

http://cdn0.hark.com...42/original.jpg

The ECM remains rock solid this evening in giving the UK its first proper countrywide cold spell

of the winter so far,with cold air spreading into Scotland during wednesday which covers all areas

by the end of next week.

This has been a consistent trend now for at least the last four runs and crucially,also

the ecm ensembles.

Some of the comments on the 12z ECM this evening have been bewildering. :blink:

[dickie1965]

By the way the GFS is currently in 4th place at +144 for accuracy, with ECM top, UKMO 2nd and GEM 3rd. I always think far too much weight is given to the GFS considering there are more accurate models available.

The thing is people default and like the GFS simply because it is the most accesible and comes out 4 times a day, even though verification stats clearly point to the ECM being number 1