Model Output Discussion 29th December - Into mid-Winter.

[Wilxy]

Evening All.

Looking through the 12z ensembles it again looks like the main uncertainty is how much energy will go over the block and whether it will be flattened out quickly or hold on longer around Scandinavia but the last run shows another slight push south of the high resulting in the colder air pushing through France, its been a trend the last few runs so its not a surprise really but it should still be settled and cold as it stands especially at night if its clear!

[Summer Sun]

 

[chris55]

It looks like we just cant seem to secure the undercut so far this winter, with low pressure over Italy, a ridge above and an Azores low you would think the undercut would be simple. However the absolute relentlessness of high pressure over Iberia, whether that be a euro slug or a ridging scandi high means we are struggling to lock in a colder pattern.

Yes we look to have a potential window in the mid term which will need to be watched, and it does look like a much colder surface flow will eventually establish, bringing some very chilly surface conditions, but somethings got to give if its proper snowfall your after.

EDIT

Here comes our window of opportunity. Can we actually get an undercut and retrogression???

 

Edited January 13, 2017 by chris55

[nick sussex]

Big differences now showing up over the west Atlantic. The ECM far better than the misery model as it splits that shortwave energy allowing the high to ridge nw.

PS just in case the misery model is the UKMO!

Edited January 13, 2017 by nick sussex

[Summer Sun]

Nothing too cold from ECM so far if you believe the 850's though surface cold remains possible especially so if we get some stubborn fog

Edited January 13, 2017 by Summer Sun

[booferking]

2 minutes ago, nick sussex said:

Big differences now showing up over the west Atlantic. The ECM far better than the misery model as it splits that shortwave energy allowing the high to ridge nw.

PS just in case the misery model is the UKMO!

And the misery model will no doubt be right again.

[I remember Atlantic 252]

Just now, Summer Sun said:

Nothing too cold from ECM so far

Could be cold there SS, inversion style, some lucky areas may have frost and freezing fog, but likely cloudy, but whatever it is, I'll be welcoming dry after Sun/Mon deluge

[swfc]

4 minutes ago, nick sussex said:

Big differences now showing up over the west Atlantic. The ECM far better than the misery model as it splits that shortwave energy allowing the high to ridge nw.

cant see it at 144 hrs nick? what am i missing 

[Ali1977]

Crazy chart from the ECM, similar to some others that haven't quite brought us the goods but this is racked with potential - this could easily bring something v v good with some luck.

Just need to retrogress the block slightly and the flood gates from the North would be in - with a greeny block !!

Edited January 13, 2017 by Ali1977

[chris55]

Window of opportunity gaining momentum on ECM.

[ArHu3]

1 minute ago, Ali1977 said:

Crazy chart from the ECM, similar to some others that haven't quite brought us the goods but this is racked with potential - this could easily bring something v v good with some luck.

and only 168h out....

[nick sussex]

1 minute ago, swfc said:

cant see it at 144 hrs nick? what am i missing

The two small lows in the Atlantic, the UKMO keeps them together. Having said that the differences now showing up between outputs and between runs suggests its chaos time.

[chris55]

3 minutes ago, swfc said:

cant see it at 144 hrs nick? what am i missing 

Im not nick lol, but if you look the Azores Low is cut off to the south, Iceland low to the north and a ridge in between, 168 shows why this is a decent place to be at 144.

[Summer Sun]

Where will this lead to...

Plenty of cold air ready and waiting if a northerly were to develop

[nick sussex]

Down to the wire on the ECM, if the troughing to the north phases with low heights in the Atlantic its game over, if they don't theres a chance but this is still looking too west based in terms of negative NAO.

Not enough retrogression of the high earlier even after a promising T144hrs output.

[chris55]

Everything needs to be a bit sharper! then we would be in business! A hard chart to read to be honest, the potential in the long wave pattern is good though. But as nick says phasing between the troughs is not what we want, if we had a more defined northerly to our north and a more defined Low to the west then bobs your uncle, but yet again our mid lat high is looking stubborn, rather than happily being sucked towards Greenland its just sitting there..

Edited January 13, 2017 by chris55

[Ali1977]

216 is so close to being an amazing chart with chance of a proper freeze!! 

Edited January 13, 2017 by Ali1977

[nick sussex]

This is painful viewing from the ECM, like its toying with us! Lots of cold air to the north but really the blocking is too far west, we need that shunted much further east.

[Day 10]

Just now, Ali1977 said:

216 is slow close to be an amazing chart with chance of a proper freeze!! 

 

[chris55]

SOOOOO SLOOOOOWWWWW, but.....full of potential (i love that word ha) But I reckon 240 will finally get there!

Edited January 13, 2017 by chris55

[booferking]

Near mess once again and that will probably 100% happen the block is to far west.

[feb1991blizzard]

You just know that the spoiler is going to be the Atlantic troughing, its close to getting in the way and engaging the troughing coming down from the arctic now, that's in FI, so god knows how many 'spinoff' spoiler shortwaves it will throw out and to where by the time it gets in to the reliable.

[Day 10]

2 minutes ago, chris55 said:

SOOOOO SLOOOOOWWWWW, but.....full of potential (i love that word ha)

Too far west, too far east, too far north, too far south, our little island always puts up these magic cold buffers!!!

[chionomaniac]

It's far better viewing than looking at a strong jet barrelling towards the UK. There won't be many times that we will look at a chart such as the ECM T+216 in history. An intriguing run - how many times have we seen Mid latitude blocking winters turn into something better - a lot more often than those with any Vortex intensification. Strat looking primed to give a nudge in the right direction as well. May have to go back and look at the set up prior to Feb 91 as I can't remember off the top of my head.

 

Edit just looked and there are similarities in the blocking pattern over the UK

Edited January 13, 2017 by chionomaniac

[Summer Sun]

ECM eventually starts bringing the colder air in at D10

 

Edited January 13, 2017 by Summer Sun