Model Output Discussion - 1st February Onwards 12z--->

[Daniel*]

Coming back to the nearer term, what's the chances of this little feature developing further to give some snow as it heads south?

We get so disjointed looking further out we miss out these little things in the reliable, chart definitely corresponds with Euro4 It is being shown on the E4, snow band tracking southwards. Might please many, Scotland, N England in particular before likely fading out or being less of a burden, by when it reaches down south.

Edited February 1, 2015 by Daniel*

[Summer Sun]

GEM shows high pressure starting to come into play more from the end of the coming week temperature by night could be very low especially over the snow fields in Scotland

 

 

Cold for most of this coming week though by the end of the week and through the weekend it shows the 850's recovering at night temperatures could drop like a stone under clear skies

 

Edited February 1, 2015 by Summer Sun

[shaky]

Latest euro4 has a stream of snow showers running into the midlands Tuesday! ! Just goes to show how unstable the atmosphere is at the moment! !

[TEITS]

Scatter begins very early on the 12Z GEFS.

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020312_0112.gif

 

My concern at the moment is the HP isn't far enough NE to bring a decent E,ly. Otherwise we want this HP to be much further W to bring a possible very cold N,ly on the right flank. At the moment we appear in no mans land but this could change.

 

On a positive a stream of snow showers through the wash is appearing on the latest EUro 4 from tomorrow night.

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020300_0112.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020312_0112.gif

[Timmytour]

Scatter begins very early on the 12Z GEFS.

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020312_0112.gif

 

My concern at the moment is the HP isn't far enough NE to bring a decent E,ly. Otherwise we want this HP to be much further W to bring a possible very cold N,ly on the right flank. At the moment we appear in no mans land but this could change.

 

On a positive a stream of snow showers through the wash is appearing on the latest EUro 4 from tomorrow night.

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020300_0112.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/02/01/basis12/ukuk/prty/15020312_0112.gif

TEITS, I think your first link is a radar one rather than of the scatter

[bluearmy]

Think I'll have an Indian tonight

Not as flippant as you might think - that model verifies pretty well in line with the gfs/gem by day 10 and is probably near to what the old gfs would have shown. The two models were often close to each other.

nothing evident to make us think that the high close to the uk is going to be far wrong but the nuances, run to run should keep this place ticking over.

[chris55]

12z short ens show how uncertain the prospects for an easterly feed is. We have scatter from -12 to +7 for the London area. All depends how far north the high can establish itself.

 

[polar vortex]

From what I can see the energy that drops south over north western Russia  post t96 makes all the difference to 

the developing pattern from there on. We need to see this energy distrupt more as in the 06z run allowing the link 

to develope  between our high and the Russian high. 

If there is to much energy and the link is broken then our high will just sit over or slightly to the north of us instead of 

ridging north east.

Edited February 1, 2015 by polar vortex

[nick sussex]

Big differences across the ne USA between the major models. The ECM develops a coastal storm which could lead to more retrogression of the high, the GFS and UKMO disagree.

[TEITS]

Big differences across the ne USA between the major models. The ECM develops a coastal storm which could lead to more retrogression of the high, the GFS and UKMO disagree.

Yes Nick and as a result the HP is further NW than the UKMO/GFS.

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020112/ECM1-144.GIF?01-0

 

If the ECM is on the right trend then I could be owing Steve M an apology!

[nick sussex]

Yes Nick and as a result the HP is further NW than the UKMO/GFS.

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020112/ECM1-144.GIF?01-0

 

If the ECM is on the right trend then I could be owing Steve M an apology!

The problem Dave is that want an either or scenario, a half hearted retrogression will end up with less cold air spilling around the top. At worst we need enough so as the trough drops south to the east this can pull some cold air back into the UK if the high topples favourably.

 

Looking at the ECM T168hrs I'd rather the GFS verified as the second attempt at retrogression looks more likely to succeed and it keeps the cold for longer.

Edited February 1, 2015 by nick sussex

[Winter Cold]

Yes, AGONISINGLY close on the ECM T168 to getting a lovely northerly reload of the cold uppers. I wonder how much more the high could be enticed west?

 

Look how close the cold uppers are:

 

[karyo]

From 168hours onwards the 12z ECM  is less cold/milder than the 0z as the high is placed further south and west with the Atlantic air riding on top. The 0z had the high over the UK which would allow fog and frost.

[nick sussex]

Yes, AGONISINGLY close on the ECM T168 to getting a lovely northerly reload of the cold uppers. I wonder how much more the high could be enticed west?

 

Look how close the cold uppers are:

 

The ECM is just doing a tease and has done this for a few runs by bringing the colder air close. To have any chance of that cold getting into the UK that upstream storm shown at T120hrs needs to track more n/ne, we need an inland runner to help develop more WAA further west into Greenland.

 

If the ECM isn't going to do that then we don't want it to verify.

 

Just reading the NCEP update and a lot of uncertainty upstream as we can see from the wildly different solutions across the models:

 

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

Edited February 1, 2015 by nick sussex

[igloo]

From 168hours onwards the 12z ECM is less cold/milder than the 0z as the high is placed further south and west with the Atlantic air riding on top. The 0z had the high over the UK which would allow fog and frost.

it looks more and more likely we will end up with a sinking HP in the longer term which usualy happens unfortunately february is lookihg like a month of to halfs from freezing to mild i havent seen any model run saying anything different

Edited February 1, 2015 by igloo

[Gibby]

Don't like the ECM tonight. Those mid latitude High's are stubborn brutes to shift and aligned to the West as the 12z shows brings days of benign rather cloudy weather with frosts and cold weather relaxing day by day in the NW flow. My most boring weather type and hope it's wrong.

PS Looks like I might be wrong as the 240 hr chart shifts it SE quite quickly. Not sure if I like that move either. Oh well it's only the weather.

Edited February 1, 2015 by Gibby

[blizzard81]

The only thing keeping me interested in the models at the moment is that they always struggle to model blocked synoptics as opposed to mobile. This means that things could change quite dramatically at relatively short notice. That's my straw anyway

[EmmaF]

Hi sorry but could someone explain to me what Steve murr was saying this morning he said to watch the models later today to see a change was that a change to mild or bck to cold ? Sorry for my ignorance

Emma

[ANYWEATHER]

The only thing keeping me interested in the models at the moment is that they always struggle to model blocked synoptics as opposed to mobile. This means that things could change quite dramatically at relatively short notice. That's my straw anyway

Yes, the Model watching will be very interesting in the days ahead, lots of changes to come.....

[blizzard81]

Hi sorry but could someone explain to me what Steve murr was saying this morning he said to watch the models later today to see a change was that a change to mild or bck to cold ? Sorry for my ignorance

Emma

He was basically saying to look for pressure rises to our north west in the hope that this will eventually bring much colder weather.

Yes, the Model watching will be very interesting in the days ahead, lots of changes to come.....

Are you expecting the block to retrogress to Greenland?

[Long haul to mild]

You'd think a great looking chart like this:

 

 

would produce a lot more precipitation than this, (even allowing for the vagaries of GFS ppn predictions):

 

 

I think this is why quite a few have been disappointed with this cold spell in snow terms; despite seemingly low heights, there's not much going on.

 

Hopefully Ian's earlier post re potential instability this coming week will throw up some last minute surprises.

 

 

[Snowman.]

You'd think a great looking chart like this:

 

gfs-0-54.png

 

would produce a lot more precipitation than this, (even allowing for the vagaries of GFS ppn predictions):

 

54-574UK.GIF

 

I think this is why quite a few have been disappointed with this cold spell in snow terms; despite seemingly low heights, there's not much going on.

 

Hopefully Ian's earlier post re potential instability this coming week will throw up some last minute surprises.

The winds aren't very strong.

 

If they where then maybe but that chart is just false hope.

[cold snap]

If there is no retrograde of the high any deep cold for this winter is done.

Two weeks of the high siting there then it sinks back for zonailty for lengthy spell then bobs your uncle march has arrived .

This has to be the form horse now

[nick sussex]

Looking at the 850's the best potential day for any convection looks like Thursday with a pool of -9 heading into the east and se. The problem is theres not a big margin for error. A nudge north of the high would certainly help and also a bit more deepening of the northern Italy low.

 

The UKMO does keep that stronger flow going into day 5 although the 850's not quite as cold by then.The fax charts do show several troughs working sw'wards from the ne on Tuesday and Wednesday also but I think its a case of seeing what pops up nearer the time as these troughs may well change.

Edited February 1, 2015 by nick sussex

[Chief Wiggam]

Surely the clock is ticking now. The sun is now producing a tangible warmth (well we are the sunniest place in the UK) Do the models take this into account? It would appear that any snow is becoming increasingly unlikely in the far South based on the most recent outputs