Model Output Discussion - 18z - 25th Nov onward

[snow drift]

The UKMO will often follow the previous days ECM, so it will probably change by the 12z.

The ecm run last night was an outlier for next weekend in the speed of the Atlantic coming back in so I think this mornings slower transition is generally more reflective of the ensemble spread last night.

The GFS flip is the most worrying, as not only does it bring back zonality and +ve NAO, the PV is then looking very well organised and that would be 2-3 weeks written off.

Where is the Atlantic?

[Matty M]

a disastrous 0z gfs totally different to the 18z run and suite. 0z ens is awful.

ECM isnt quite as bad as last night but still poor.

UKM remains bullish for cold but is becoming inreasingly isolated.

[Iceberg]

The energy hasn't done anything yet terry as its still several days away !!!

If you trace the js back from runs that put the bulk of the energy north instead of through the block, you end up with a small difference in an us elbow js off the eastern seaboard, if the elbow is fully formed at t72 it engages the lp, earlier intensification and the energy goes up the west side of Greenland.

I would say that the meto model is normally not the best at us js prediction, but neither do the other models have a good handle on it.

[snow drift]

I don't think you really believe that yourself do you CC ? The pitfalls of this evolution were obvious and as it has come into the nearer timeframes, the energy at Northern latitudes has sunk us as it so often has in the past.

A real problem for Exeter today when they update their outlook, assume they will follow a blend of the ECM ensembles and the GFS.

Brilliant. I fear for non experienced members. You know this is not resolved yet your post suggests its all over. Very unhelpful to many who read posts to see what might happen moving forward. The energy in the North may win but it also may not. Balanced view would be much appreciated by many, I would suggest.

[Matty M]

All about that tiny SW south Greenland near T96hrs

Does the ECM/GFS have the higher res to deal with it better than the UKM/Nogaps

I think so. I expect a ECM 0z type solution, not dreaded zonal attack but weak breakdown.

[snowking]

Well you really couldn't make it up could you!

UKMO/GFS vs ECM becomes UKMO/sort of ECM vs GFS.

There's a few things to note here, first of all while the ECM looks different synoptically, it's still showing a significant cool down through the week, and cold enough for wintry showers in the east from around 120 onwards.

The UKMO remains simply stunning, whether its still consistently wrong remains to be seen, but it must be noted given the met office update that the MOGREPS must continue to support cold.

The UKMO will have egg on its face if it does prove to be wrong.

However, as for the bait being thrown around on here this morning, don't bite it!

This is a situation that is far from resolved and members can attempt to make a forecast based on NWP as much as they want to...but when the NWP clearly doesn't have a clue, the resultant forecast will be just as clueless

SK

[The Northern Ramper]

I don't believe the Ukmo follows any models previous output, I'm pretty sure that isn't written in the programme. FI starts with the Canadian low and if the Ukmo has modelled this correct then it deserves all the plaudits it gets.

All about that tiny SW south Greenland near T96hrs

Does the ECM/GFS have the higher res to deal with it better than the UKM/Nogaps.

Do you have anything to back that up with?

[Isolated Frost]

SO pleased the ECM 12z came out well- good to see egg on face on those who pronounced the spell over 120 hours ago based on nwp alone- ignoring the background signals is ignorant and very dangerous..

anyway- expect the GFS to follow suit, whether it'd be today's 06z or tomorrow's 18z- it's a matter of time. There will be plenty of changes and kneejerk reactions to come still, many haven't learned it appears

[The Northern Ramper]

I missed the "I think so" off

[SLEETY]

MAJOR BREAKING NEWS FROM THE USA!

The final bulletin from our USA correspondent, remember this is not computer generated but done by the duty forecaster having looked at all of todays outputs including that nauseating ECM!

Take a look at whats near Nova Scotia on day 4 then enjoy the rest:

Day 5

Day 6

Lets hope for an ECM backtrack tomorrow.

Well the ecm has backtracked and the gfs has followed yesterdays 12z ecm run So it is not over yet if the gfs has the track of the low wrong then the rest of the run is for the bin

Edited November 26, 2012 by SLEETY

[Paul_1978]

Well well well, would you credit the UKMO?

Model watching in the last 24 hours......more ups and downs than a tart's knickers.

[kate1]

Brilliant. I fear for non experienced members. You know this is not resolved yet your post suggests its all over. Very unhelpful to many who read posts to see what might happen moving forward. The energy in the North may win but it also may not. Balanced view would be much appreciated by many, I would suggest.

I would doubt there are many non experienced members (myself included) who hang on TMW's every word...We have been here before, on a number of occasions, and clearly there is something about this situation that the models are struggling with. Each run is just one possible solution to the problem, not the definitive answer at this stage - I'm trying to remember that whenever someone posts that 'winter is over' - or the reverse.

[swfc]

For someone with limited knowledge of the nao,strat warmings ete im finding odd given some of the last week or so comments regarding the positive outlook with regard to the blocking,southerly jet and very strong signals for sustained cold.If all the ingrediants are or were there why are things changing in the models so quickly?Granted the ukmo is still on track but to my untrained eye the pressure over greenland ete has been gradually diminishing for a while now.Was this not or is it not a signal of the pv picking up pace and gathering strength?.Ive been told to follow trends and not specific runs but here we are with the ukmo holding a cold spell together unlike 24-36 hours ago?.Also have the 500mb charts picked up on this as they were touted as being the ones to watch ?Excuse my limited knowledge and thanks in advance to any replies.Ps i now hate the word trend!!!

[Ian Brown]

So the ukmo produce the charts on the ecm and gfs ens?I really didnt know that.

I don't mean the UKMO model run, I mean the METO extended outlook. I would expect them to stress great uncertainty on the 6-15 dayer until this is resolved later today.

[bluearmy]

This is far from resolved. Even md atlantic depressions are making differences later in the runs. we could still end up with a sizeable chunk of the uk under a blanket of snow by the middlenof next week. Itnjust depends on the timing of the energy from the west, and what is coming from the north re blocking. Throw spanners into the works like the shortwave that comes up mid atlantic onthe ecm op today and you are going to struggle to pin down beyond 5 or 6 days.

granted that it has changed somewhat since the beginning of the weekend but if you 'up the stakes' you may reap bigger rewards.

[Jonan92]

GME/DWD at 72h

[TEITS]

You know its funny despite all the differences in the model output my outlook has not really changed. I feel the reality of the period around +168 will be a blend of what the ECM/UKMO are predicting. I shall use the ECM +168 as an example.

http://www.wetterzentrale.de/pics/Recm1681.gif

Around this period I believe we will see an attack from the Atlantic. However I also believe the angle of attack from the LP will be aligned NW-SE with our HP block further S and being more influencial than what the 0Z ECM shows. This means a risk of a snow event for some locations and remaining cold thereafter.

Another chart from the ECM which hasn't been mentioned is the +240.

http://www.wetterzentrale.de/pics/Recmnh2401.gif

What on earth has happened to the PV? That is what I call a -AO which means a continuation of the cold is likely into the 2nd week of Dec.

[dancing daisy]

Experienced watcher, inexperienced forecaster here.

Doesn't this happen every time snow is predicted? It's like being on a rollercoaster, snow is such a fickle beast we all know that things have changed rapidly, even down to the actual day.

As someone who is trying to learn I have to say it is unhelpful to see negative doom & gloom about something that is being forecast days ahead based on just one chart.

Carry on kids.

[Paul]

No. Fax charts are routinely at odds with UKMO-GM modified output and this proves a very regular discussion point when we create synoptic charts for TV use.

And PS re wider discussion: Key part of UKMO thinking into the longer MR is not solely EC Monthly (GFS beyond circa 8 days not really rated) but MOGREPS. The latter's strong signal from MOGREPS-15 has remained a critical driver behind recent UKMO 10-15d prognosis alongside that from EC32.

Thought this would be relevant this morning..

[Ian Brown]

You know its funny despite all the differences in the model output my outlook has not really changed. I feel the reality of the period around +168 will be a blend of what the ECM/UKMO are predicting. I shall use the ECM +168 as an example.

http://www.wetterzen...cs/Recm1681.gif

Around this period I believe we will see an attack from the Atlantic. However I also believe the angle of attack from the LP will be aligned NW-SE with our HP block further S and being more influencial than what the 0Z ECM shows. This means a risk of a snow event for some locations and remaining cold thereafter.

Another chart from the ECM which hasn't been mentioned is the +240.

http://www.wetterzen.../Recmnh2401.gif

What on earth has happened to the PV? That is what I call a -AO which means a continuation of the cold is likely into the 2nd week of Dec.

I think that is a very optimistic outlook Dave from where we sit this morning - the Azores High is already sat there and with the energy coming off Greenland it is only going to pull the jet North. If that happens we have no chance of staying on the cold side of the PFJ.

[Methuselah]

I would doubt there are many non experienced members (myself included) who hang on TMW's every word...We have been here before, on a number of occasions, and clearly there is something about this situation that the models are struggling with. Each run is just one possible solution to the problem, not the definitive answer at this stage - I'm trying to remember that whenever someone posts that 'winter is over' - or the reverse.

I think it would be sensible if folks didn't hang on to anyone's every word?

[weathergeek]

Correct me if I'm wrong cos I am as amateur as they come but....

When I joined this forum last yr I quickly learnt from posts that the UKMO shouldn't be trusted, that the Meto forecasts were useless (fair enough, bad track record up to then) So when they showed consistent Mild, people ignored them in favour of the odd flickers of hope we got from ecm/gfs.

It then transpired that the UKMO/Meto had been right all along and all we did get was mild....until they correctly predicted the "turning colder/snow" that we got layer on??!!

So maybe we should have more faith in UKMO?

As I said, I may not know what I'm talking about but pls don't shoot me down, just wanted to know if my memory serves me correctly?!!

Ta!x

[Frosty.]

This was my reaction to the Ecm 00z and Ukmo 00z this morning, the cold outlook is hanging in there, the pattern gets pushed further west so the azores high and that atlantic low is held out of harms way. A colder trend throughout this week with a freshening Northerly airflow, today is the last day when temps will reach 10c, colder and colder but drier and drier apart from some showers in the north and east. Today there could be almost 3 inches of rain for parts of northeast england so more flooding is likely but the flooding threat peaks today, then subsiding and later in the week we should be having widespread frosts and plenty of sunshine but with wintry showers draped around northern and eastern coasts with snow on hills, then a good chance of a wintry weekend and start to next week with some snow around and sharp frosts, the Ecm 00z shows a breakdown to the cold snap but in the transition there could be some snow and is then followed by a reload and then more frosty weather, even the gfs 00z brings winter in FI but once again the ukmo 00z is rock solid cold, as it has been in recent days.

It's great to see the ukmo and ecm are Brrrrrrrrrr this morning

[Isolated Frost]

Very promising H5 anomaly update

Svalbard+arctic high staying strong... expect the nwp to be measured and move towards this solution through the next few days-

[TEITS]

I think that is a very optimistic outlook Dave from where we sit this morning - the Azores High is already sat there and with the energy coming off Greenland it is only going to pull the jet North. If that happens we have no chance of staying on the cold side of the PFJ.

You know me mate I always try and be optimistic.

When I look at the models I try to be objective and not get involved in the usual swings and roundabouts and instead take a balanced look at all the output. It is clear these models are struggling and whilst the ECM isn't perfect it has certainly moved back towards a cold outlook compared to last nights 12Z.