Model Output Discussion - The final stretch to Christmas

[Great Plum]

Atlantic train starting to roll back in as early as T144.

Ummm....

http://www.wetterzentrale.de/pics/Rtavn1441.gif

Not on that GFS run it isn't?

[festivalking]

Watch the ECM flip the other way later just to spite us. Complete pandemonium if it does. Seen it happen though!

[bluearmy]

thats the gfs showing a 30 odd mb difference in the baltic at day 6 between the 12z and 18z.  thanks goodness we have the gfsp to save us. the normal gfs cant be done away with fast enough imo.

[Downpour]

Huge backtrack by the GFS.

Good to see.

Detail to be confirmed later.

[phil nw.]

Well something had to give as those upstream ridging differences started at day 4.Finally the GFS has found some Christmas spirit for cold lovers.

with better Greenland ridging and the downstream tracking of the low more se in Europe.

A better positioned high as a consequence building behind the low.

Let's see if the trend for more amplification can build tomorrow onwards with an increasing chance of a an easterly further on.

Even a UK high with cold surface temperatures and frost would be a start.

[I remember Atlantic 252]

Atlantic train starting to roll back in as early as T144. 

 

you still on 12Z? looks very cold for Southern England there, high pressure well in charge

[Carlrg]

Ummm....

http://www.wetterzentrale.de/pics/Rtavn1441.gif

Not on that GFS run it isn't?

At T162 the Southerly flow is just off the coast of ireland.

Edited December 23, 2014 by Carlrg

[bluearmy]

and if the russian high can 'suck' up our block then the good ol pub run will undercut and 'cold pool' us. classic 18z output!

 

incidentally, the para without split flow to our west so the high will struggle to get far enough north to allow any very cold uppers to reach us.

 

these charts beginning to smell of the 'murr sausage' 

 

a strong jet streak headed east as the op arrives at low res should be enough to derail the run

 

EDIT:  interesting that it doesnt. perhaps the most interesting thing to take from the 18z run.

Edited December 23, 2014 by bluearmy

[damianslaw]

Lots going on at the moment - a week likely to provide a host of everything, very mild, very windy weather followed by colder drier frosty weather then further wet weather with potential for snow in places and a much colder foggy frosty tail end..

 

Very interesting stuff.

 

Models today are beginning to agree on the track of the low pressure, but we are still 3 days away, so still room for many more changes. However, what is notable is how they have come into line with UKMO and the Met Office forecast - the balance of cold occurring rather than mild after the 27th, now roughly 65% in favour.

 

Won't have much time to dip in and out of this thread over next 3 days or so, indeed  I will certainly give it a rest on Christmas Day.

[liam300]

Under cut at 168hrs, could enhancing the energy and developing the easterly.

Edited December 23, 2014 by liam300

[95 Degrees]

18Z should be censored, that's some serious eye candy on offer in the SE on the 29th/30th, but can it sustain it?  

 

[CanadaAl]

and if the russian high can 'suck' up our block then the good ol pub run will undercut and 'cold pool' us. classic 18z output!

Looks like you might be right. 1035mb over estonia

[Allseasons-Si]

At T162 the Southerly flow is just off the coast of ireland.

Look east Carlrg.

[Mark Neal.]

GFSP 18Z. Here is the look at snow risk as the low moves SE.

 

96hrs.                                                 102hrs.

    

 

108hrs.                                                       114hrs.

   

 

Looks to me that risk is in Scotland & NE england as the low moves SE with colder air digging in, then pushes further south as the night goes on. Early hours and morning sees SE see some of the white stuff before it clears away and pressure starts to rise in behind. 

Alot to go before we can see any white stuff, but encouraging stuff, March 2013 last time for some of us down South for Snow falling so this potential is not be jumped at lol. 

Edited December 23, 2014 by Mark N

[Nick F]

GFS's operational track over last few runs has little support from the 51 00z ECM/EPS members, the majority and ens mean take the low SSE or SE across mainland UK something akin to 00z UKMO. Mind you little support from 06z GEFS for the ECM op or even UKMO, with most taking the low SE down the North Sea. Be interesting to see if there's still a stand off on the 12Zs and if there is, what the t+96 and t+120 faxes coming out later this evening make of the low.

So the stand off that still played out on the 12z suite comes to an end! GFS ops does seem to have this habit of suppressing height rises once lows clear SE into the continent - so always wary when its more eager than the Euros to bring back in the Atlantic.

But such a drastic change in track of the Fri/Sat low from previous op, makes you wonder how the model can justify consistently sticking with one track (in recent runs taking a low SE down the North Sea) then suddenly dumping it with a low track much further west.

[legritter]

GFS P  frame 141hrs a real sausage dangling over the uk from southern russia ,and dont anyone dare get out the crayons .a good run hope tomorrow carries on with all models supporting a good HL block ,im waiting for tonights 120hr fax chart could be interesting ,cheers gang .

[CanadaAl]

so IF.. big IF this pulls off... looks like we could be looking at the question of undercut or not this time next week. Quite the turn around. Looks too good to be true 

Edited December 23, 2014 by CanadaAl

[Matty M]

So the stand off that still played out on the 12z suite comes to an end! GFS ops does seem to have this habit of suppressing height rises once lows clear SE into the continent - so always wary when its more eager than the Euros to bring back in the Atlantic.

But such a drastic change in track of the Fri/Sat low from previous op, makes you wonder how the model can justify consistently sticking with one track (in recent runs taking a low SE down the North Sea) then suddenly dumping it with a low track much further west.

 Yea it's almost like there was some human input in the initialisation to correct some bias, but probably not

[Cloud 10]

and if the russian high can 'suck' up our block then the good ol pub run will undercut and 'cold pool' us. classic 18z output!

 

incidentally, the para without split flow to our west so the high will struggle to get far enough north to allow any very cold uppers to reach us.

 

these charts beginning to smell of the 'murr sausage' 

 

a strong jet streak headed east as the op arrives at low res should be enough to derail the run.

 

Yes,not a perfect sausage,but its a start. :w00t:

 

[CanadaAl]

so IF.. big IF this pulls off... looks like we could be looking at the question of undercut or not this time next week. Quite the turn around. Looks too good to be true 

and what's this i see? lol FI fun 

 

Edited December 23, 2014 by CanadaAl

[Blake]

Incredible... 10c change in the South/South East.

 

[Met4Cast]

The 12z ECM hinted at an undercut but couldn't quite get there.

The 18z GFS just did what the ECM couldn't quite manage

 

 

Hopefully tomorrows runs continue the longer term trend towards undercutting and an Easterly - GFS(P) not overally interested, though

[Allseasons-Si]

Undercut alert! :smiliz19:

 

 

i am happy with today's runs,lets hope it continues tomorrow.

[Mark Neal.]

Undercut alert! :smiliz19:

 

gfs-0-204.png

 

i am happy with today's runs,lets hope it continues tomorrow.

Happy New Year haha. Be interesting to see what the Ensembles show tonight as some have been hinting at possible undercut territory, with the odd chance of Scandi High was talked about earlier. Intriguing times.

Edited December 23, 2014 by Mark N

[snowice]

Undercut alert! :smiliz19:

gfs-0-204.png

i am happy with today's runs,lets hope it continues tomorrow.

well with low heights now pushing into the med this will help establish and maintained an easterly flow which should bring cold easterlys west.I think ukmo ecm and now gfs will upgrade in further runs and Mr Murr will be awakened! Edited December 23, 2014 by snowice