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

[Panayiotis]

This is looking a lot like the ECM with the shortwave dropping SE!

[swfc]

at 140-156 hrs the front disrupts and splits

[Tamara]

These are pleasant to see

http://www.ecmwf.int...t!2013020312!!/

[chionomaniac]

The GFS pendulum has just swung to the slider side.....

[Panayiotis]

We now want that in coming low on the Azores high to ridge heights north towards Scandi...

[MR EXTREMES]

http://modeles.meteo...nh-0-138.png?18

Notice the GFS is flaunting its biggest weakness today & the 18z shows it beginning to back down- The GFS will want to move the entire energy West to East with no seperation / trough disruption that allows systems to seperate.

For the last 2 days this has been the case with the GFS, well now we find that the energy in the atlantic is beginning to seperate- 1 pulse going NE & the other SE- however the 18z wont quite get there & the shortwaves will have minimal distance between them-

eventually when the GFS catches up that shortwave diving Se in the atlantic may be in the same place, but the rest of the energy will be a long way further north west- hence the whole blocking will be NW....

S

wow i just ran through and i see that and the gfs is stepping in a good direction from what i can see.

[LomondSnowstorm]

http://modeles.meteo...nh-0-138.png?18

Notice the GFS is flaunting its biggest weakness today & the 18z shows it beginning to back down- The GFS will want to move the entire energy West to East with no seperation / trough disruption that allows systems to seperate.

For the last 2 days this has been the case with the GFS, well now we find that the energy in the atlantic is beginning to seperate- 1 pulse going NE & the other SE- however the 18z wont quite get there & the shortwaves will have minimal distance between them-

eventually when the GFS catches up that shortwave diving Se in the atlantic may be in the same place, but the rest of the energy will be a long way further north west- hence the whole blocking will be NW....

S

So far its been an absolutely textbook GFS backtrack as you say Steve, run by run the trough disruption is occuring further and further west:

18Z last night:

0Z this morning:

6Z:

12Z:

and 18Z tonight:

This is a trend we'd very much like to see continue.

[TEITS]

The GFS pendulum has just swung to the slider side.....

Indeed and taking into account the ECM/Mean you have to fancy that somewhere next Sunday could see a snow event.

If I had one gripe with the ECM is the lack of projected cold upper temps especially late on in the run. I realise this could change and most probably will.

[chris55]

GFS now dropping the shortwave south east much like ECM which is a good thing, however we can see that the UK may well be placed on the boundary between the cold and the less cold, with the snow line, or generally colder air (depending on positioning) further west or east.

Steves thought's suggest further moves west from GFS over the next few runs, but watching how far west the SW is will be crucial. We could see a big snow event, a damp squib, or cold and dry.

Edited February 3, 2013 by chris55

[Cloud 10]

Message to programmers of NOGAPS:

If it ain't broke,don't fix it!

[Ice BIast]

Meanwhile, the NOGAPS 18z has produced a perfectly shaped Scandi high.

You were too fast for me Cloud10.

Edited February 3, 2013 by lce Blast

[mulzy]

Message to programmers of NOGAPS:

If it ain't broke,don't fix it!

To be honest, I'm worried that the NOGAPS is showing this. I'll be more at ease if it were showing mild SWlies.

[Grimsby Snow Lover]

Well into FI territory I know but just look at uppers for next weekend! The -10 is in touching distance of the UK!! I have been comparing the GFS run with the ECM run from earlier and they are very similar up to 168hrs which is well out beyond the reliable. The bonus is the GFS has sided towards tonight ECM, lets just hope the consistency of the ECM remains in future runs with the GFS, UKMO and other models following suite.

http://cdn.nwstatic..../h850t850eu.png

Edited February 3, 2013 by Grimsby Snow Lover

[Ice Day]

GFS at 240 - 18z vs 12z. Pretty much sums up its performance at the moment. In keeping with the current theme, can I say it's 'floundering'?????? I'll get my coat!

Edited February 3, 2013 by Ice Day

[MR EXTREMES]

Well into FI territory I know but just look at uppers for next weekend! The -10 is in touching distance of the UK!! I have been comparing the GFS run with the ECM run from earlier and they are very similar up to 168hrs which is well out beyond the reliable. The bonus is the GFS has sided towards tonight ECM, lets just hope the consistency of the ECM remains in future runs with the GFS, UKMO and other models following suite.

http://cdn.nwstatic..../h850t850eu.png

VERY CLOSE CLOSER THAN LAST NIGHTS RUNS IM GETTING CONFIDENT ALTHOUGH ITS STILL NEEDS A COUPLE OF DAYS.

SORRY CAPS LOCK STUCK I THINK.

[Nick F]

The GFS pendulum has just swung to the slider side.....

Given the big support of the 12z ECM op from the EPS for the slider, it's not surprising ...

Although it's fairly subtle on the 500mb/slp charts, quite a pronounced omega shape block building at the 500-300mb level to the north of the UK now on 18z GFS, which in effect aids in the disruption of the trough coming down from the PV and creates the slider low.

Really interesting to watch this unfold.

Edited February 3, 2013 by Nick F

[snowmadchrisuk]

Good to see 18z try and backtrack , although it is a very messy run , ruins most Snow chances with Milder air elc.... Although I think this is just the start of a back track towards the ECM , We want to see the Slider get into the Channel via the West of us aka ECM and not right over the Country , or it will temporary mix our Cold air out ... Anyway good start and that's the main thing ..

[swfc]

staggering deep fi with great blocking

[Bonjangle]

GFS at 240 - 18z vs 12z. Pretty much sums up its performance at the moment. In keeping with the current theme, can I say it's 'floundering'?????? I'll get my coat!

Best Plaice to be at the momment , i am aving a Whale of a time tonight with these charts ... cod's sake lets have some more

[Panayiotis]

GFS 18z ends with a Greenland high, a really good run throughout with only a few days of average weather, hope this trend continues tomorrow along with the other models!

[JP1972]

Best Plaice to be at the momment , i am aving a Whale of a time tonight with these charts ... cod's sake lets have some more

I'm backing the ECM from here on in but some will take the GFS bait.

[snowmadchrisuk]

There's a thought I wonder If this NE Setup could eventually back West and become a Greenland High , that would prolong the setup fro the whole Month ... Looking forwards to tomorrows runs ..

[Cleeve Hill]

Great set of charts there if you want cold and some longevity. Looking increasingly like a cold month with the P.V finally moving away.

[Snowman.]

GFS 18z ends with a Greenland high, a really good run throughout with only a few days of average weather, hope this trend continues tomorrow along with the other models!

I have actually been calling for one since its slow backtrack I think a GH will end Feb and start march.

There is my forecast just a real gut feeling one!

[Severe Siberian icy blast]

Very nice northern blocking in fi on tonight's 18z , infact it's a cold run, even when we have a westerly type airflow which is a very brief affair early in fi , but a good run , typical backtrack as has been the case all day , and very very solid ECM ens , actually shocked us all i think ? Really didn't expect to see them look so cold and rock solid on an undercut , almost the same as our jan cold spell , but think with stronger heights to our northeast .

What's interesting about the 18z is the migrating west toward Iceland and toward Greenland for the high pressure in deep fi , with a very blocked Atlantic .

So I think I can say all in all a very wintery feel to the models now with the gfs falling into line , and the ukmo a kind of inbetween between them all , but feel its only a matter of time now until we see them all agree.

Don't get hung up regarding the 850's not looking deeply cold as John says they do change from run to run and most certainly will be very cold coming over Europe this time of year especially the winter Europes having . Get the right set up , then the cold will come . Feb 2005 was a rare event regarding a mild Europe .