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Model Output Discussions 18z 31/01/2016

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More MJO activity, more GWO phase 5 from GEFS today. Enough to help sharpen the U.S. pattern up with a slower progression east, but can we get the transferal of Atlantic LP to the east of the UK and/or trough disruption?

12z GFS says yes to both, but only after a painful struggle, and in the middle of lower-res:

h850t850eu.png

The risk is that the Atlantic LP in 6-7 days time becomes slow moving to our west as the westerly momentum drops out. The 06z showed this scenario. It could lead to some interest if such a feature then drifted into Europe and with a slow enough progression over the U.S. but we are picking out straws from some 8-12 days away here.

 

Now to consider a possible positive tweak to the strat. forcing; comparing 12z on the left with the 06z on the right, the Arctic High for days 10-14 is notably stronger on this run compared to the past few efforts, and the stratospheric warming puts a bit more pressure on the vortex at 30 hpa for example:

npsh500.png npsh500.png

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The result by the end of the run is that the vortex is over the Kara Sea as opposed to Svalbard. A relatively small improvement on its own, but something to watch out for in case the propagation of the warming through the stratosphere is being underestimated at all.

I know Recretos won't like me for suggesting this, but while Cohen keeps insisting on better strat. propagation, there's a chance this trend could evolve into something more significant. Just don't go hanging your hat on it.

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43 minutes ago, Geordiesnow said:

Its always seem to be days 8-10 though from what i read on here, the reality is unfortunately there is no real prospects of snow opportunities in the outputs and unfortunately also with a strengthening sun even upper air temps of -5 would deliver to bring much in the way of cold weather, warm SST's don't help. 

There is more chance of another deep area of low pressure hitting the UK than any snowfall at the moment. 

I understand your scepticism but this a bit more than just random variance in FI. This is growing signal for a slowing of the Atlantic and possible ridging and blocking developing within that time-frame. Sure, if we take GFS Op at face value then we don't get a cold snap/spell but if we look at the trend between runs and the trend within the ensembles then there is reason to be more optimistic. That is where I am coming from - blame the new hat! :hi:

 

 

36 minutes ago, mountain shadow said:

I'm struggling to see any WAA at 500 hpa on that chart Mucka. Indeed, it is the lack of WAA which allows the next bowl shaped low to come barrelling threw. 

It is clearly depicted over the UK and if you run it on a little you will see the resulting cut off heights over Greenland.

Indeed the ridge behind is quickly flattened and we carry on our merry zonal way but there is reason to believe things will not work out that way and that instead we will see better amplification and any Atlantic ridge joining forces with previous height rises over Greenland whether they be due to WAA ahead of a diving low or Arctic heights or both.

I'm not trying to say the 12z GFS Op is blocked or cold, clearly it is neither. I am just saying that the synoptic int he day 8-10 range will allow for Atlantic blocking and a cold pattern develop if we continue to see this trend.

I really wouldn't be surprised if we see a decent Atlantic ridge on tonight's ECM at day 9/10 but won't be too dismayed if we don't so long as we see low pressure diving into Europe and at least some indication of height rises toward Greenland.

If by tomorrow no Ops are showing this then I will be less optimistic - might even go for another hat burning ceremony.

 

Edit.

Just for clarity I will show p16 for the sort of pattern I think may be emerging.

192 height rises over Greenland from combined Arctic heights and WAA in Atlantic sector. 

gensnh-16-1-192.png

 

216 weak cut off Greenland heights with amplification upstream and potential Atlantic ridge.

gensnh-16-1-216.png

 

240

Atlantic ridge joins up and reinforces Greenland high.

gensnh-16-1-240.png

 

How sustained that pattern may be if it develops is open to doubt but it should at least result in a cold snap.

Edited by Mucka
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The GFS 12hrs run quickly pushes that  central USA trough into the Atlantic. A lack of amplitude means theres little chance of developing anything colder for the UK.

Its output seems to be reflecting its reluctance to move the MJO. Unless that trough hangs on upstream and allows sufficient time for a mid Atlantic ridge to build north ahead of it then theres little chance of anything interesting.

So far both the GFS and GEM are going the wrong way and unless the ECM can change this trend then we're fast running out of time.

Its like pulling teeth to even get a northerly toppler and I think the last chance saloon is close to shutting down for this winter.

I'm about to call last orders unless the ECM bucks the poor trend so far this evening!

 

 

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I do not have much interest whether it will snow on northern hills - however this chart looks decent courtesy of Michael Ventrice cyclonic yes - but it may become cold enough for snow (not just for the usual culprits) the AO & NAO going negative!! hooray.

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We can get a taste of what is to come and build on 240 chart from this morning - expect to see more amplification on the 12z hopefully slightly more east based.

A SSW appears almost certain albeit a minor one we have not seen a SSW since early 2013, I cannot draw even the slightest hints of February 98 - how someone could write of the winter it's beggars belief in my honest opinion. 

image.thumb.jpeg.efd19f817a148a773e428e2

Edited by Daniel*
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A colder Gfs 12z for most of the UK with more in the way of frost and even some snow in the south which the earlier runs today didn't have. I feel with a generally nw / se jet profile we will have cold opportunities which will be helped if the jet stream slows down and allows longer gaps between Atlantic systems. Through high res, the chance of snow is higher in the north and especially on hills but then we all have a shot at something more wintry...this is not the time to give up!:D:cold:

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I wonder if tonight's ECM det. will have any decent Atlantic amplification at Day 8 or 9 or whether its at Day 10 as ever....

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29 minutes ago, Daniel* said:

I do not have much interest whether it will snow on northern hills - however this chart looks decent courtesy of Michael Ventrice cyclonic yes - but it may become cold enough for snow (not just for the usual culprits) the AO & NAO going negative!! hooray.

image.thumb.gif.3b9a37b250226d429ec185df

We can get a taste of what is to come and build on 240 chart from this morning - expect to see more amplification on the 12z hopefully slightly more east based.

A SSW appears almost certain albeit a minor one we have not seen a SSW since early 2013, I cannot draw even the slightest hints of February 98 - how someone could write of the winter it's beggars belief in my honest opinion.

image.thumb.jpeg.efd19f817a148a773e428e2

The ECM would take several days from there to develop colder conditions. The low near the UK would need to run ese and clear otherwise you're stuck under a modified flow within the low circulation and that's only if the upstream trough hangs back allowing the high to ridge further north. In terms of writing winter off if we take these outputs to day ten that's the 11th February which leaves just over two weeks of winter. We simply don't have time for any more slow burners, either the outputs improve over the next few days or its basically game over. The ECM may well look better than the GFS given its MJO view and at this point the MJO is the only thing stopping me from throwing the towel in. That needs to get its skates on like the UKMO MOGREPS.

March snow unless it has some stunning synoptics doesn't float my boat so we need to hope that there are some major changes in the outputs over the next few days.

Lets hope the ECM can salvage my mood!

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1 hour ago, Timmytour said:

just a thought....but  today it appears the Karymsky volcano in Russian Kamchatka's eastern volcanic zone spewed ash up to 3km into the air, according to the Regional Emergencies Ministry. That's not the first bit of volcanic activity in that region this winter.

It is possible such eruptions have a major direct on what is thereafter modelled.  Is there any correlation between all the models seeming to suddenly change tack within a relatively short time-frame from showing one thing to another, (obviously within a small region but evolving to have bigger consequences down the line)  and things such as volcanic explosions?  

I'd referred to it in the strat thread a few weeks ago in response to a similar question, Reports at that point said the ash cloud reached 8km, so at the very lowest level of the strat if close to the pole, and 3 km falls well below that. The 1815 Tamboura eruption which helped to create 'the year without a summer' in 1816 had a column that reached up to 45km so these are of a very much smaller magnitude. I've also read research which suggests that there can be an effect on summer temperatures but that there is no particular correlation with subsequent winter temperatures.

I'm still expecting Hekla in Iceland to blow relatively soon, there's a chance that could be a biggie of Pinatubo (1991) proportions, VEI 6 and that had a 45km column.

ECH1-216.GIF

Meanwhile ECM slower with the evolution, at 216 not yet the chance to develop ridging up to Greenland.

Edited by ukpaul
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At 240, well the slower evolution helps to lower heights in central southern Europe more and there's the start of what could be some pretty decent ridging. That cut off low though is the sort of feature which we'd need to act nice.

ECH1-240.GIF?01-0

Edited by ukpaul

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4 minutes ago, marksiwnc said:

Having seen no comments on the ecm is probably rubbish.

Less rubbish than the GFS upto T192hrs but then the slow moving deep Atlantic low just hangs around waiting to phase with the upstream trough.

 

 

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And there we have it, another potentially decent looking Day 10 chart from ECM. Will it ever get to t+0?

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I personally can't even see the potential at day 10, more like clutching at the last straw.

Wheres the cold going to come from?

ECH0-240.GIF.png

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Slower evolution here but good to see some consistency the ridge also less west based. :good: 

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1 minute ago, snowray said:

I personally can't even see the potential at day 10, more like clutching at the last straw.

Wheres the cold going to come from?

ECH0-240.GIF.png

It would come. Proper WAA into Greenland and a negative tilted trough off US seaboard. The Atlantic low would slowly push East and a proper Northerly would follow. 

Knocker has posted the GEFS in the moan thread which shows the 'potential '.

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How many more times this winter are we going to see potential at day10 from the ECM.... not to say that this time it wont happen.. if the ECM is still looking like this at the weekend and the other models are close to it then i might just might take notice....

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2 minutes ago, snowray said:

I personally can't even see the potential at day 10, more like clutching at the last straw.

Wheres the cold going to come from?

ECH0-240.GIF.png

I agree. That trough just to our west will hang around like a bad smell and slowly fill. Meanwhile, another bout of brutal cold blasting out of the US helping to fire up the jet yet again. More wind and rain for the UK downstream. Dreadful!

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4 minutes ago, blizzard81 said:

I agree. That trough just to our west will hang around like a bad smell and slowly fill. Meanwhile, another bout of brutal cold blasting out of the US helping to fire up the jet yet again. More wind and rain for the UK downstream. Dreadful!

Exactly. 

No sign of any block forming where we want it either, terrible.

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Everyone is in a hurry to get the cold here, I'm one of these too.....however, the potential is from mid month onwards so we're not really there yet...Give it time, something will crop up by the end of the week...I hope...

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7 minutes ago, mountain shadow said:

It would come. Proper WAA into Greenland and a negative tilted trough off US seaboard. The Atlantic low would slowly push East and a proper Northerly would follow. 

Knocker has posted the GEFS in the moan thread which shows the 'potential '.

I don't share your optimism with regards to a negatively tilted trough over the eastern US. This looks as though it will blast through. Look at the temp gradient.

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1 minute ago, Frosty. said:

I must be missing something here, 10 years of model watching but I don't think the Ecm 12z is showing any wintry potential at day 10, it gave me a sinking feeling and I was concerned Nick Sussex was about to destroy his laptop!..:D

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Lol! I was close to doing that. I agree the ECM at T240hrs isn't good and that won't evolve into anything interesting. The Atlantic ridge will just get flattened and the upstream troughing will phase with the mid Atlantic low.

That mid Atlantic low is a real problem, we need that much further east earlier on.

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2 minutes ago, snowray said:

Exactly. 

No sign of any block forming where we want it either, terrible.

Very deflating run wasn't it? I am really tempted to book a plane ticket to the US for next week! Can't afford though lol.

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13 minutes ago, blizzard81 said:

Very deflating run wasn't it? I am really tempted to book a plane ticket to the US for next week! Can't afford though lol.

Deflating yes ,but maybe that higher pressure over the far north may just may send lows later in its modelling further south .

IT does seem though that rain fall totals will continue ,and possible named storms ,damn it i need my fix ,chins up gang still time left ,interesting model discussion :yahoo:

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Well, I'm not interested in putting lipstick on a pig. I can see nothing of any interest unless you live at least 1000ft above sea level in the north of the country all the way out to the middle of February. We will need exceptional synoptics to bring nationwide snow that lasts beyond 10am in the morning once we get into the second half of February . I just cant see it. far too much mobility in the synoptics, frigid cold spilling into the Eastern USA that will just fire up the jet. A minor SSW ( if we are lucky) that will, more than likely displace the PV into an unfavourable position; no strong established cold pool just to our East ( our best/classic winter have always had this) ; a strong and established high pressure belt to our south that has no opportunity to ridge north to a decent latitude, every time it tries it just get squashed by the jet ; An MJO signal that's more dithery than my aged mother.. Do I need to go on.. Please don't get me wrong, I am here because I love cold and snow in winter, I'm not here to celebrate mild wet Atlantic mush or warm and dry February's. I've tried to be positive but I have had enough. I admire those who are staying positive and promising good times are just around the corner. I will continue to keep a watching brief but I am very saddened to say that I am officially throwing in the towel on any hope for meaningful nationwide snow that last a length of time that it can be enjoyed this winter.

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16 minutes ago, legritter said:

Deflating yes ,but maybe that higher pressure over the far north may just may send lows later in its modelling further south .

IT does seem though that rain fall totals will continue ,and possible named storms ,damn it i need my fix ,chins up gang still time left ,interesting model discussion :yahoo:

Legritter has the right attitude, chin up gang...still another 28 days of winter left!! The Ecm 12z is just one op run, don't throw the damn towel...yet:laugh:

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