Winter Model Discussion 18Z 3/2/13 onwards.

[TEITS]

the ecm ens mean drifting towards a mogreps picture in the 9 day+ area. the block to our east slowly giving way again .

Flicking between the ensemble mean from +192 to +240 it looks more of a stalemate to me.

Personally im not assuming the Atlantic will move in as suggested by the ECM Det just yet.

[bradymk]

ECM still cold until day 7/8 before it gets less cold. However I would easily take a sig snow event at 144 over a sustained cold spell currently. Temps still look to continue below avg with the mean never getting above -2c but its just not the sustained very cold period some were seeing. However this is only run and the EC Ens have chopped and changed a lot recently but cold, v cold at times in the next week with a chance of sig snow event but then turning less cold as the high backs away looks a good call.

[Ryan Dutch Weatherman]

Look at this run from the Australian, also the Indian model good end also the Chinese.

[Frosty.]

Well it takes the Gfs 00z until T+384 hours to finally get there

[Jason M]

Some quite bizarre model interpretations going on here.

GEFS mean height anomalies and T850s painting what would be a reasonable picture for the day 6-15 range (in addition to days 1-5 which are cold).

Trough signal over Europe is persistent and gets sharpened in the 11-15 day range as the ridge signal in the Atlantic gets organised. Temperatures below average throughout.

Looking through the GEFS this morning though the ensembles are so chaotic that there is virtually no agreement at day 7. Should we be putting much stall in these charts this morning (serious question and not a dig)

Jason

[johnholmes]

this link gives a more relaxed view of the two major models T+24 out to T+240

[Glacier Point]

Jason, if they were so chaoitic, the mean anomaly would be incoherent. Those representations are showing a relatively strong signal given the potential peturbations. The other notable thing is the timing. One would expect the further out you go the more incoherent the signal but the reverse is true here.

Edited February 5, 2013 by Glacier Point

[Gustywind]

From a uk perspective though those mean height anomalies could indeed be correct but the uk could still end up on the wrong side of the block, scuppered by micro features like the Norwegian shortwave which stops the cold getting far enough west. Isn't this basically what happened in December, when again all the height anomalies pointed to a cold pattern?

[Methuselah]

Can we please have a day without the childish personal comments? Not only are they unedifying, they clog the thread with distracting drivel...the upshot of which is that quite a few posts (that might usually be allowed to remain) get moved or deleted, after only a cursory inspection...

If you want your posts to be read, please think about what they contain. Every little helps!

[Ryan Dutch Weatherman]

Btw this was in the Netherlands [ijsselmeer/lake] 10 day s ago.

Crowing ice !

[Blizzardof82]

Ian F just posted on South west thread

Trough followed by occlusion remnant later both expected to offer more widespread ppn however. Either way, accumulations small and patchy as expected. Some major upstream sampling issues identified by Exeter way far W have key implications for model genesis Fri-weekend so nothing in NWP at that range trustworthy.

[weather eater]

this link gives a more relaxed view of the two major models T+24 out to T+240

http://forum.netweat...00#entry2586471

A good post John and explains why some of us were not going to jump on a particular model just because it was showing what we wanted to see. Although its starting to look like the ECM has done very well here, it will not change my attitude next time, both models are fallible and have shown it many times in the past, of course that stats show that the GFS is more fallible than the ECM but the margin is not so large as to just ignore the GFS altogether, my caution may prove to have been futile this time and I'm happy to say so, but it will serve me well in the future.

[Frosty.]

there is way too much worrying about days 8,9,10 + when we have an increasingly very cold outlook showing this morning with significant snow in places and severe frosts, enjoy what we have for however long we have it. The gfs still looks a mess to me but the ukmo, ecm, gem, nogaps all bring a freeze.

Edited February 5, 2013 by Frosty039

[chris55]

Superb ECM again this morning for Sunday, if we can can one more snow event this winter then I'd be happy,

UKMO could be very interesting as well, not quite sure where the snowline would be on the 144 chart though,

GEM is a peach as well!

Edited February 5, 2013 by chris55

[swfc]

there is way too much worrying about days 8,9,10 + when we have an increasingly very cold outlook showing this morning with significant snow in places and severe frosts, enjoy what we have for however long we have it. The gfs still looks a mess to me but the ukmo, ecm, gem, nogaps all bring a freeze.

yes and we in sheffield have just had 5cm snow in just over one hour.Anyway as you say looking beyond any kind of reliable time frame is futile .

[Roger J Smith]

The commando raid on UKMO operations centre was a success, no injuries reported.

Ever wonder what the model names are? Here's a guide:

GFS = Ghastly for snow.

ECM = Easterly coming matey

UKMO = Useful Knowledge Might Obtain

GME = Great Must Extend

GEM = Got Easterly Maybe

BOM = Best Observed Merrily

NOGAPS = Never Opened Generally All Previous Sagas

RJS = Right Just _____________

and there you have the uncertainty factor laid out.

(don't say it)

[weather eater]

there is way too much worrying about days 8,9,10 + when we have an increasingly very cold outlook showing this morning with significant snow in places and severe frosts, enjoy what we have for however long we have it. The gfs still looks a mess to me but the ukmo, ecm, gem, nogaps all bring a freeze.

Indeed snowing hard here at the moment, plenty more to come today, strong winds, drifts starting to appear even in the garden, this year I have seen far more snow than 2010, by the time we have done with this winter, then maybe more snow than the last three years combined. It’s been excellent so far, the only thing missing has been the extreme cold and one truly memorable snowfall.

I’m certainly not worried about the post weekend evolution currently displayed by the models those are going to change and as I said earlier I’m happy with my contributions to the thread over the last few days, I post honestly and to the best of my knowledge, limited as it is and I don’t post to be liked.

[BLAST FROM THE PAST]

Oh well if its to be that pesky shortwave that strikes the fatal blow to the cold then at least before that it goes out with a bang with that snow event at 144hrs.

Unfortunately once that shortwave appears its downhill from there as that allows too much energy eastwards and its beyond repair at that point.

We'll see if that shortwave does verify, hopefully not but certainly its an unwelcome addition to a generally positive start today.

Well after seeing what is developing and the precise timing AND synoptic pattern of the LRF by RJS 4 months in advance NOT days or a week+ as per models, I am not concerned re that shortwave. There is slower retrograde signal over the top of this quicker development thus I suspect that we will see the HP dominate and continue to do so. Why would I trust a model that couldn't see this less than two weeks in advance compared to someone who's research saw it last autumn?

UKMO T144 chart of the day, as many have said...a very good model to have onside. GFS is simply a joke....Good For Sh..

BFTP

Edited February 5, 2013 by BLAST FROM THE PAST

[Tamara]

Look at this run from the Australian, also the Indian model good end also the Chinese.

The Australian BOM is derived from the UKMO model - I think the main difference is the resolution is lower

Well for sure having watched the ECM over the last four days or so, output after output, plot the course ahead on an apparently non consensus evolution - it finally leads all the models to a sinking low pressure and increasingly likely snow event. The exact track of the low is still to be plotted exactly, but we will see this clarified in due course. Furthest west obviously ideally best to keep the coldest air and lowest dewpoints for most.

The whole pattern is very reminiscent of January just gone by, and also has shades of February last year - especially if we can consolidate the easterly which arrives on the back of the weekend 'snow low', sandwiched between Scandinavian High pressure and low pressure over Europe

[Timmytour]

Around a week ago I said I wasn't looking at the model output for a sustained cold spell and would prefer to see a big snow event. I said this because in recent years I have seen many days of lying snow and now I want a big snowfall. Well the models this morning are perfect because that is pretty much what they show. Rather difficult to say how much snow would fall and the exact location but at the moment the output favours S/C England/Wales rather than N England.

The useless GFS/GEFS continues to be as reliable as using seaweed and I would prefer to count the number of seagulls flying around than using this model at the moment.

As i recall TEITS.....at a time in late January when others, who now shout loudly from the rooftops about what ECM is showing, were berating the fact that there was nothing in any model to get excited about, you were growing in confidence and cited the 10th February as a potential event.

Nothing's written in stone yet of course but as the date gets nearer, I have to take my hat off to you

I'm surprised Gibbo hasn't received any criticism from certain quarters for failing to show ECM in bold in his latest summary

Edited February 5, 2013 by Timmytour

[snowking]

Here's what Lorenzo was referring to earlier from the ECM32:

Very clear cold signal up until around 11/12th - thereafter a split developing for the week 2 period (hence the slightly less cold signal). Thereafter, as per usual, not much of a coherent signal.

Slightly easier to see on the box plots:

Nothing especially mild in the offing, but less cold the signal from this run beyond 11/12th

SK

Edited February 5, 2013 by snowking

[Methuselah]

As i recall TEITS.....at a time in late January when others, who now shout loudly from the rooftops about what ECM is showing, were berating the fact that there was nothing in any model to get excited about, you were growing in confidence and cited the 10th February as a potential event.

Nothing's written in stone yet of course but as the date gets nearer, I have to take my hat off to you

I'm surprised Gibbo hasn't received any criticism from certain quarters for failing to show ECM in bold in his latest summary

I remember TEITS predicting the onset of real winter, around 10/2. I don't recall any mention of a not-very-special 'event'...Dave?

[Snowman.]

We still need to be care as this shortwave was picked up by the GFS who quickly dropped it.

ECM might have the same here so where unable to know until next run.

But when other models show it....

We have a problem.

[TEITS]

I remember TEITS predicting the onset of real winter, around 10/2. I don't recall any mention of a not-very-special 'event'...Dave?

I always felt the 10th Feb was a pivotal day thanks to my large crystal balls.

However I never really went into detail and just said winds veering NW,ly to N,,ly and then NE,ly around the 10th Feb.

Slowly but surely the GFS is getting there.

http://www.wetterzen...s/Rtavn1261.png

NOGAPS is even more progressive than the ECM/UKMO with regards to the block to the NE extending W.

Really would laugh if the NOGAPS outperforms the GFS.

Edited February 5, 2013 by THE EYE IN THE SKY

[swfc]

06z seems to be stuck on 102 hrs???

Edited February 5, 2013 by swfc