Model output discussion 8th Feb - Cold for now, but then what?

[knocker]

The ext EPS this morning has a somewhat diffuse vortex over the Pole and downstream a trough western Atlantic with Azores pushing north in the mid and eastern section accompanied by a trough extending south to the eastern Mediterranean to our east. Ergo upper flow in a NW quadrant and portending a N/S split and temps a little below average.

[Man With Beard]

GEFS 06Z ... by D10 almost all members have heights centered near Portugal with influence through Biscay. Mean chart fairly representative

You'd be very hard pushed to get a cold pattern from that - much more likely a warm one. The only way is for heights to pierce and separate troughing to the east and the west, like this one. Not the main cluster, though:

Mind you, the ECM mean is quite different and less likely to be mild:

Some possibilities for a southerly jet - you'd think there'd be a cluster with heights to the north, lead to colder air getting south. Cold enough for snow at this time of year though? Questionable.

[Frosty.]

I'm still looking for cold and snow potential and once again I've found some on the GEFS 6z which show several arctic outbreaks during the mid March period and from what I've read we (coldies) are very much in the game as far as cold and snow is concerned at times during the next 4 weeks. 

Edited February 28, 2017 by Frosty.

[Frosty.]

Even in the short term the Gfs 12z shows a risk of rain turning to snow, especially on hills across parts of wales, the north midlands and northern england late tomorrow and overnight into thurs am.

[knocker]

Trough deconstructs and brings cold to Timbuktu

[Frosty.]

High pressure ridges into the sw / s towards the end of next week for a time on the Gfs 12z and has a second attempt during the following week which is more successful and ends with a nw / se split  but overall it's an unsettled run with temps around average.

Edited February 28, 2017 by Frosty.

[snowray]

Some interesting charts this evening. ECM at T144, Scandi high? Very cold pool of air up there too.

[snowray]

Heres the GEM @ +T144 for comparison.  

[Frosty.]

Well I'm doing my best to find some cold snowy cheer and again the GEFS 12z is showing some wintry weather from polar / arctic maritime source towards mid March and beyond..even more potential than the 6z because there are some scandi highs too so I think March could be a very interesting month with some cold and snowy periods possible.

Edited February 28, 2017 by Frosty.

[knocker]

Well have a look at the ecm around T156 as the trough disrupts it drags in some very cold from the NE around the high pressure and sinks south into Germany. Close but no cigar.

[snowray]

13 minutes ago, knocker said:

Well have a look at the ecm around T156 as the trough disrupts it drags in some very cold from the NE around the high pressure and sinks south into Germany. Close but no cigar.

Surely we are well overdue some upgrades for being so good this Winter? Still a long way off of course and at least the GEM is running with a similar idea.

[Frosty.]

Well the Gem 12z stands out tonight because it shows the coldest outlook as high pressure develops to the north although the Ecm isn't far behind..it keeps the interest going for coldies and not forgetting tomorrow night when snow could cause some disruption across parts of wales, the midlands and northern england..a lot going on.

Edited February 28, 2017 by Frosty.

[snowray]

Yes, Euro4 shows snowfall likely over a large swathe of NW England tomorrow night, mainly on slightly higher ground, where I would think that there could be some moderate falls of snow.

Even our snow starved Oldham contingent might be lucky enough to get a covering.

[Frosty.]

1 minute ago, snowray said:

Yes, Euro4 shows snowfall likely over a large swathe of NW England tomorrow night, mainly on slightly higher ground, where I would think that there could be some moderate falls of snow.

Even our snow starved Oldham contingent might be lucky enough to get a covering.

Yes it's an evolving situation 're tomorrow night..I have a feeling it will upgrade the snow risk and apart from the rain / snow it also looks like becoming very windy across the southwest in particular with westerly severe gales for a time..hope the woodshed survives!

[snowray]

3 minutes ago, Frosty. said:

Yes it's an evolving situation 're tomorrow night..I have a feeling it will upgrade the snow risk and apart from the rain / snow it also looks like becoming very windy across the southwest in particular with westerly severe gales for a time..hope the woodshed survives!

Indeed. 

Also think your location will do very well for that snow.

[Frosty.]

Just now, snowray said:

Indeed. 

Also think your location will do very well for that snow.

I think the pennines certainly will but I'm hopeful the rain will turn to sleet and then wet snow on lower ground too..fingers crossed

[Summer Sun]

Looking at the ECM ens and we may start and see some longer drier spells as we move through next week I think we may end up with a north/south split with the south milder but still chiller north

 

Edited February 28, 2017 by Summer Sun

[knocker]

The anomalies this evening are in pretty good agreement upstream and only fair downstream which i feel might just be due to the timing of the phasing of the colder and warmer air and nothing drastic. Something the det runs will need to sort for the detail.

Anyway still an Aleutian ridge with quite an intense vortex NE of Alaska (It has started it's migration towards Franz Joseph Land) with associated trough running south west. In the Atlantic still the trough in the west and high pressure in the Greenland/Iceland area which leads to a quite complex analysis in the vicinity of the UK sorting the interaction of the aforementioned and the Azores ridging and a trough to the east It's this area that the det runs will need to clarify. Suffice it to say at the moment the percentage play is for a more settled period, probably a N/S split and temps a little above average

As mentioned in the later period the vortex has done a runner towards Franz Joseph Land and weakened whilst at the same time the high pressure in the Greenland are has also declined. There is no agreement on this but the general idea  is for some ridging in mid Atlantic with a trough to the east running down to southern Europe. How this amplification pans out is the key as we could be looking at temps a fair bit below average if this drags colder air in from a northerly quadrant.

 

 

 

[damianslaw]

Continued suggestions we will see a strong ridge building through the country with associated deep trough to our east, a flow from the N/ NE could quickly surface and with it cold uppers. ECM hinting at such development medium range, GFS also in its longer range output. 

[Singularity]

33 minutes ago, damianslaw said:

Continued suggestions we will see a strong ridge building through the country with associated deep trough to our east, a flow from the N/ NE could quickly surface and with it cold uppers. ECM hinting at such development medium range, GFS also in its longer range output. 

Aye, these rumblings are really messing with my CET thinking this month. Very inconsistent output in terms of the details for our little slice of the hemisphere over the past week. Signs of very extensive blocking, in fact incredibly so by day 10 and it almost seems as if the models aren't sure how to handle such a messed up longwave pattern. Prepare for the weirdest March on record... 

[Purga]

Why the Dickens couldn't we see this kind of pressure profile earlier in the year?

Particularly the troughing over Europe a feature that has been singularly lacking this past winter,

[Stationary Front]

We did, it's always at day 10 plus.

[Gael_Force]

8 minutes ago, Stationary Front said:

We did, it's always at day 10 plus.

I don't think you saw anything quite like that in the winter, even at day 10. That's a low ice and a low solar signal for spring and early summer according to some of the links given in the ice thread and in depth model thread. Plausible and unwelcome!

[feb1991blizzard]

The 18z GEFS are an absolute stonker, the synoptics that interest me most at this time of year are developing waves / troughs / cyclonic NE'lys, like Dec 8 1990, 6th April 2012, late april 1981 (you need continuous blisteringly heavy snowfall without interruption so it can settle), I could see this happening in mid March, I'm just wondering though, it seems the 18z GEFS seem to amplify the pattern and throw out members that give right ol blizzards, only for them to have steadily downgraded by the 12z to the extent where a single flake at any normal altitude is hard to come by throughout the whole suite.

[Dennis]

Bullseye some good movements for a late cold sign....