Model Output Discussion 18th Nov.2013-12z onwards.

[Great Plum]

ECM 216

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

http://www.wetterzentrale.de/pics/Recm2162.gif

Still very cold -5 air for England and Wales but milder air incoming?

[Great Plum]

ECM 240

http://www.wetterzentrale.de/pics/Recm2401.gif

http://www.wetterzentrale.de/pics/Recm2402.gif

Milder upper air for us all by this stage - possibility of an inversion perhaps?

ECM is still going for a sharp cold snap - it's coming into the semi-reliable now but 5 days is a long time in weather forecasting!

[lamppost watcher]

Day 3-5 met office update this morning mentions wintry showers up north

Monday, rather cloudy, some light showers, mainly in the northwest. Mostly light rain edging southeastwards through Tuesday and Wednesday. Showers following, perhaps wintry over high ground in the north.

Looking forward to a possible upgrade for day 6-15

Edited November 30, 2013 by RoryHennessy

[bluearmy]

It's all about the eastern seaboard and timing re how cold and how long the initial cold lasts. Ecm op ultra consistent. The noise around heights building to our east post day 10 getting louder still. Not sure if ECM day 10 looks like it fancies a reload northerly before it ridges convincingly to our ne.

[tinybill]

Day 3-5 met office update this morning mentions wintry showers up north

Monday, rather cloudy, some light showers, mainly in the northwest. Mostly light rain edging southeastwards through Tuesday and Wednesday. Showers following, perhaps wintry over high ground in the north.

Looking forward to a possible upgrade for day 6-15

all i say could  be worse after the pub run  looking cold and with snow here  in the  uk by friday

[SMU]

Morning-

I am still very troubled this morning by the large disparity between the UKMO and the ECM.

What is worrying is 2 fold

* Whilst the ECM is the best resolved model I dont think I have seen 1 run of any model amplify the energy (now at 144) and take it west of greenland-

This is crucial to the ECMs success and its been uber consistent with that outcome on 5 of the last 6 runs-

* The second worry is the UKMOs halfway house solution of 'somewhere in the middle towards iceland' at day 6 will see a quick warm spike for england after just 36 hours of northerlies, although the cold may return south quickly again as the back edge passes through- there is also a way to longer term cold if this comes to fruition but lets wait for now-

So im holding station today and waiting for the 12s UKMO-

I am concerned today though- of interest will be the ECM ens especially the control.

Regards

S

Edited November 30, 2013 by Steve Murr

[Smiler1709]

Gfs is completely different to yesterday's output, could it of smelt something different? Maybe but most properly not. With the very cold ECM run I'm thinking by the time we get closer to the event we will find ourselves somewhere in between the gfs and ECM. Let's see what the ukmo has after 144 hours. Due to my location on the south coast I could care less if this northerly fails to deliver. I'm looking for the high on the ECM to push into scandi and bring in a easterly. Some models have suggested this but way out in fi so about as much good as a Train set with no plug.

Edited November 30, 2013 by phil nw.
Removed unsavoury comment

[IDO]

We have been here before with ECM op calling it wrong (2 weeks ago) and gradually with its tails between its legs follow the GFS. ECM seems to favour over amplification on its ops and that is why we get those stellar charts at D10. Its 0z verification continues to fall and is now below 0.4:

Both are falling so this may be a difficult prediction scenario, but that is a poor ECM stat.

The 8-14 height anomalies:

Edited November 30, 2013 by i'm dreaming of...

[Mark Parsons]

Hi Smiler, can you display your location please!

Edited November 30, 2013 by Mark Parsons

[Frosty.]

Gfs is a bag of s### this morning

Really? not ooooooooop north it aint

Edited November 30, 2013 by Frosty.

[karlos1983]

Hmm, I live on the south coast and I think that Northerly would deliver pretty much everywhere on the ECM. Although Easterlies tend to be a better setup for Southern England I agree. But I'll take a Northerly if that's all that's on offer, especially the northerly blast shown by the last couple of ECM's outputs.

[Snowmaggedon]

Hmm, I live on the south coast and I think that Northerly would deliver pretty much everywhere on the ECM. Although Easterlies tend to be a better setup for Southern England I agree. But I'll take a Northerly if that's all that's on offer, especially the northerly blast shown by the last couple of ECM's outputs.

I think this is going to end up being a Scotland only affair as it usually does. Just my gut feeling

[nick sussex]

So we're now left with the 3 different solutions compared to yesterdays 2, very unusual to now see the big 3 all disagreeing, normally its a 2 to 1 split.

You can see the difference the upstream pattern makes as regards phasing/timing issues. NOAA have highlighted poor run to run continuity this morning:

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[karlos1983]

Looking at the UKMO at +72 and +144, the PV seems to be moving East. Or am I reading that wrong?

[nick sussex]

Looking at the UKMO at +72 and +144, the PV seems to be moving East. Or am I reading that wrong?

Yes it moves east and then the trend later on is to bring the PV back to Canada, amongst all the model disagreements that looks like a solid trend.

[karlos1983]

Yes it moves east and then the trend later on is to bring the PV back to Canada, amongst all the model disagreements that looks like a solid trend.

Ah ok, cheers Nick. ðŸ‘

[terrier]

I get the feeling this morning that the ECM is leading us all up the garden path again. Remember if it looks too good to be true then it probably is. Me personally think this will be a Scotland only event and I expect the gfs to be correct again with the ECM coming kicking and screaming into line with it like it did just a few weeks ago

[Smiler1709]

Hmm, I live on the south coast and I think that Northerly would deliver pretty much everywhere on the ECM. Although Easterlies tend to be a better setup for Southern England I agree. But I'll take a Northerly if that's all that's on offer, especially the northerly blast shown by the last couple of ECM's outputs.

The models are still well out of range for anything reliable so it could change, and if it does change I bet it will downgrade and the gfs and ECM will find middle ground, also frosty precipitation charts are useless this far out, 24 hours out and that can change. Don't get me wrong I won't be moaning at this colder outlook but some off the ramping will get the hopes up of so many only for them to be disappointed when this cold snap arrives.

[bluearmy]

We have been here before with ECM op calling it wrong (2 weeks ago) and gradually with its tails between its legs follow the GFS. ECM seems to favour over amplification on its ops and that is why we get those stellar charts at D10. Its 0z verification continues to fall and is now below 0.4:

cor_day10_HGT_P500_G2NHX (2).png

Both are falling so this may be a difficult prediction scenario, but that is a poor ECM stat.

The 8-14 height anomalies:

 

did you look at the day 5, 6 and 7 stats where we have the divergance ?   ecm is not a tool for day 10. i have always felt that, ironically, its higher resolution causes it to be far too defined with its pattern by day 10.  by that i mean its error at day 7/8 gets magnified as the run continues. perversely, the lower res models, although also on the wrong track, are less likely to end up so far away from the correct long wave pattern. 

 

and as far as two weeks ago was concerned, the model was indeed too amplified but by the same token, the others were too flat.  as it happens, the ecm was right to call high heights in the GIN area (against the other models) but they were quickly flattened.  the general rule is to look for a middle ground solution when we have such disagreement. (perhaps not this time). it will be resolved (excuse the pun) by tomorrows 00z's.

 

the ecm ens mean spreads show that the mean is not quite amplified enough around iceland by day 10 and that the margin for error on the cold plunge (assuming  it happens) is most definitely west of where the mean shows it.

 

       

 

       

 

 

trying to make sure that i dont make the same mistake as before on the spreads, the  day 10 option shows either 509 or 550 heights around iceland. i have looked through all the output and decided that although both are feasible (gfs op is in the 510 area), the ecm suite looks more likely to be headed in the 550 direction. (perhaps not after seeing the dutch ens)

Edited November 30, 2013 by bluearmy

[IDO]

The mean is not that useful at the moment with all models struggling. However it does highlight that the op is at the cold end of the ens:

Mean T168: OP T168:

Mean T192: OP T192:

So how strong this northerly is has not been resolved, however if it happens, current output on longevity remains confident that it will be a toppler.

Edited November 30, 2013 by i'm dreaming of...

[Gibby]

Hi everyone and good morning. Here is my no frills text account of the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday November 30th 2013.

 

All models continue to show High pressure in control of the UK weather for the next 3-4 days with a fine day today with plenty of sunshine but overall cloudy conditions developing from tonight with benign and quiet conditions lasting thereon until the middle of next week with temperatures close to average.

 

The GFS operational then shows winds increasing across the North on Wednesday and further South on Thursday. A band of rain will be moving South across the UK on Wednesday followed by another on Thursday/Friday with clearer and colder conditions reaching the North briefly with wintry showers in places. This dry and cold weather may reach the South too very briefly before it is swept away NE by Low pressure along with milder, wet and windier weather later next weekend. This then sets up a much more mobile pattern with details irrelevant at this range but the general theme would be wet and windy weather alternating with brief colder interludes with wintry showers across the North at times. Overall temperatures would return to average but maybe returning rather colder later.

 

UKMO this morning ends next week with cold weather plunging South on Friday with rain in the South clearing to showers of sleet and snow, albeit briefly and mostly across the North and coastal areas in the East and West next weekend with frosts at night and a cold and strong Northerly wind.

 

GEM today shows no more than a glancing blow from the cold weather next weekend across principally Northern and Eastern areas where wintry showers may occur for a time with frost at night. Further South and West changes will be very tempered and in any event the trend from the start of the new week is for all areas to become mild and rather cloudy with Southerly winds from the Canaries to embalm the UK in mild air as we move into next week, perhaps with some rain in the North and West.

 

NAVGEM shows a brief encounter with colder air next weekend preceded by some rain and a fresh West wind as a depression moves steadily East across the North. A day of wintry showers look possible before a brief ridge crosses East drying things up perhaps with a night frost or two next weekend with temperatures below average at that time.

 

ECM today shows the most coherent cold snap next weekend with a two to three day window from next Friday of cold NW then North winds with snow showers, appreciable over Northern hills likely for a period. A ridge of High pressure moving steadily SE to our SW does show the flow being moderated by milder air rounding the High and down across the UK on a NW flow by the start of the new week with rather cloudy and benign conditions returning for many away from the far East where it may well still feel cold and breezy at times perhaps with a few showers, mostly of rain by then.

 

The GFS Ensembles show that (leaving the operational run to one side as it looks very suspect this morning) the weather looks like staying generally close to average temperature wise as we move through the run. The cold snap though still present for the North and East makes little inroads over the South before SW winds and more changeable weather looks the favoured consensus between the members through the second half of the run. As mentioned with SW winds predominating later in the run and with High pressure likely to be to the SE it will be mild for many especially to the East of high ground with most of the rain towards the North and West.

 

The Jet Stream currently travelling East at high latitudes well to the North of the UK slowly sinks further South as we go through next week as High pressure tries to give way somewhat. However, after a brief lull a surge of strong jet energy is then sent across the Atlantic and across the British Isles later in the run pumping up the potential for some deep Atlantic depressions to our NW later in the run, borne out by some of GFS's output this morning.

 

In Summary there is still a period of quiet anticyclonic weather for most areas between now and Wednesday. However, all eyes are on events thereafter with potential for a cold plunge of air to occur over Britain next weekend albeit rather brief. The American models seem to want less to do with this and allows the South to escpae almost entirely while the North sees something of a glancing blow at colder weather for a time. The Euro models are more productive though with ECM leading the field in producing a 2-3 day window of very cold and wintry weather with snow showers and very sharp night frosts. Nevertheless, it looks nothing more than a brief affair with the Jet Stream shown to power up to our West later throwing the potential for the Atlantic to create some large depressions out to the NW with all areas looking favoured to come under their influence with spells of rain and showers along with occasional gales. Though technically mild towards the end of the period some colder injections could affect the North at times with wintry showers over the hills.

[Smiler1709]

Good update Gibby, puts it into perspective and no needless ramping.

[Ali1977]

The meto should have a better idea as to if the ECM is over doing it or not, let's see what the GFS says in an hour. We are now in the time frame where every model should slowly start coming together to give a more accurate picture.

[lorenzo]

Just looking at EC ens clusters for 14th December.22/51 members going for Scandinavian High + Mid-Atlantic Trough (looks similar to the GFS 18z chart shown above).

29/51 for Scandinavian Low + Mid-Atlantic High!

 

Remains annoying that the ECM removed those postage stamps, still saves us all some worry. More sensible odds than the 80:20 split in the ensemble suite last year that left everyone kicking the cat !!

 

At 168 Colder 850hPA temps dialling in on the UK and Europe getting a proper wintry blast, interesting that this is almost a diluted version of some of the rampant GFS control run charts from a couple of weeks back.

 

GFS and ECM 

 

Beyond that a couple of control charts from the ECM suite out at 300, to show the easterly flow appearing on the ensembles.

[Smiler1709]

Ramping is half the fun on here, and never needless... Its a weather forum not a forecasting tool. Go watch the BBC weather if you want a sober reflection on the weather

There is a thread for ramping, I call that place dreamland. I think this thread is for more realistic output discussion.