Model Discussion Thread - 15th Jan

[Anti-Mild]

I have been a member of this forum for 8 years now and i can scarcely recall a time that has been as up and down as the last few days.

IMHO look for further height rises to our NW - a delayed reaction to strat warming. From there, who knows?

[legritter]

evening gang ,im liking tonights posts ,its nice to be back after a week of not looking at any charts or reading any weather in any paper or media . gfs seems to be out on its own but is tempting us to some possibilities in its later stages . if the ECM 120 /200 hrs comes of im sure there will be many a happy poster . met office being very carefull at the mo ,but im sure when they see anything news worthy we will know 120 /144 hrs before .most main modells do show large pressure rise in north atlantic , and some of them globally have pressure north of equater a lot lower come 20th , but as always with forecast modells ,lets not get carried away and get taken to PARADISE , but saying that im HOOKED and starved of snow so ecm ,met office ,and gfs bring it on ,gfs out soon , regards legritter

[SMU]

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

spot the long term trendsetter with -10 MAX

S

[wizard.muh]

Hi All

Please mods don't delete.

Just wanted to acknowledge the expertise in this MD forum. I have been reading for many years now, I find it difficult to understand the charts so rely heavily on others.

I respect so many of you with your knowledge and it makes reading this forum very interesting and in winter very compelling. I appreciate that at times it gets very heated in here but my advice to others is that I know now who I want to read and who to skip over, this makes the read a lot easier.

I know this isn't model discussion as such but I know over the past few days it has been a testing time. But, please believe everyone, that for total amateurs such as myself it is fascinating.

Just felt it needed saying.

Cheers

P.S. I believe that winter will bite us back! and looking at the charts to my very inexperienced eye, something is brewing!

My thoughts too..... (Minus the PS, but I really do hope so) excellent thread, thank you all so much (sorry not relevant to current output).

[OldMetMan]

Today's model output has some interesting potential, plus an amount of confusion beyond about 144H,

The general consensus of the current block breaking down, followed by a more mobile westerly turning northwesterly looks reasonable, with the European upper trough amplifying accompanied by a steady decrease in thickness values as progressively colder air spreads south.

Beyond that, a variety of possible outcomes are given depending on which model and run time you look at. The 12Z ECM looks particularly weird as it doesn't seem to know where to go beyond 144H with deepening LP coming SE from Iceland and then E - doesn't look right to me. More likely I would have thought successive LP moving SE over and to the W of the UK tend to deepen the European upper trough until eventually we end up with an easterly and rising pressure to the N and NE - I've seen that happen a few times. Given that we still are forecast to have that Russian HP not too far away, I would bet on an easterly.

The GFS sort of does the above over a longer time scale but with an unsettled LP interlude until the final few charts for the 12Z which have a tantalising glimpse of some really cold continental air moving into the UK.

I can't shake the feeling that upstream long wave features are going to suddenly amplify, with a more pronounced mid-atlantic ridge and a general slowing down of the polar jet. I keep looking for clues in satellite imagery but, apart from the E Pacific trough deepening, there is not enough to go on at the moment.

All in all I would say this is a difficult situation to call, not just in the medium- to long-term but even within the next few days, as there are still changes from run to run in the detail of the timing of the HP breakdown, which is pretty unusual. Interesting though!

[bobbydog]

Worth noting that the strong message coming out of all NWP output at the moment is for an opening out of the contours (mean deceleration of the westerly winds) across the North Atlantic as the low heights to the north lift out and pull back west, associated with the upstream wavelengths being seriously altered by that Aleutian ridge. The Azores ridge is going to get a serious yank back west allowing the longwave trough and attendant shortwaves to cut across on a NW-SE axis. If you follow the longwave pattern and the ensconsed 850 values, the only way for this to go is underneath the block.

GFS ensemble mean package suggests a strong building ridge over the top of this block by day 10 and a split flow developing over Europe by day 12 (easterly potential high). Of note, the 00z parallel GEFS came up with a strongly negative NAO and the 12z GEFS ensemble mean has popped in a strong ridge developing south of Greenland at the very end (day 15), but a strong signal at that range.

and for us 'divs' - how would Sian Lloyd say that??

[Jason M]

and for us 'divs' - how would Sian Lloyd say that??

Something like this?

but with a 50% chance of lots of this......

[bluearmy]

and for us 'divs' - how would Sian Lloyd say that??

the azores high will remove west and the russian high will move west and the depressions will have to head southeast into europe. there are other ens signals for an easterly flow aswell within two weeks, theres loveleeeee boyo !!

Edited January 15, 2012 by bluearmy

[bobbydog]

the azores high will remove west and the russian high will move west and the depressions will have to head southeast into europe. there are other ens signals for an easterly flow aswell within two weeks.

thanks BA, though i doubt Sian would even say it like that lol

[The Northern Ramper]

That's like me saying people are too grumpy and they should lighten up. I hope your post was heavy on the irony?

Can you stick to the models please.

Edited January 15, 2012 by Osbourne One-Nil
I would if I knew anything about them!

[phil nw.]

the azores high will remove west and the russian high will move west and the depressions will have to head southeast into europe. there are other ens signals for an easterly flow aswell within two weeks, theres loveleeeee boyo !!

Something like this maybe

http://www.wetterzentrale.de/archive/ra/1985/Rrea00119850109.gif

http://www.wetterzentrale.de/archive/ra/1985/Rrea00119850112.gif

http://www.wetterzentrale.de/archive/ra/1985/Rrea00119850114.gif

http://www.wetterzentrale.de/archive/ra/1985/Rrea00119850117.gif

-10 uppers over the uk.

[chionomaniac]

Right let's stick to the models now.

GFS already different at T+48 with the strength of the low close to Iceland!

[Cecil Hogmanay Melchett]

The ecm 12z operational is a lovely run with the jet gradually taking a more southerly trajectory.

This chart at 144h is loaded with potential.

http://www.wetterzentrale.de/pics/Recm1441.html

We can see the see the jet being disrupted,it doesn't evolve perfectly but that huge anticyclone over NWRussia is making its presence felt as it extends westwards to Scandy.

If we can get to the ecm 144h chart i think the game is on,the trouble is there is still big model differences as early as 120h.

Knife edge stuff.

[The Northern Ramper]

Right let's stick to the models now.

GFS already different at T+48 with the strength of the low close to Iceland!

Different how? Further east?

[PolarWarsaw]

Low looks less intense to me @t48

[chionomaniac]

Different how? Further east?

The clue is in the word strength.

It is less deep in then 18Z.

[john mac]

lovely to see some good discussions on here tonight, 18z on its way out in a minute. Fingers crossed it will follow the ECM. I have to say GP your forcasting has been great this winter and at the moment it looks like its going to continue.

[Snowstorm1]

Different how? Further east?

If I am reading it right which i may not be! ; I think instead of been ejected SE it is phasing so looks worse run or am I talking a load of tosh?

[snowlover2009]

http://www.knmi.nl/e...agse/index.html

spot the long term trendsetter with -10 MAX

S

I am guessing that maximum is in the netherlands or one of those small countries to the east of France? Imagine how cold It would be here?

[john mac]

Mild interlude later this week already being shortened on the 18z. -5c over scotland and northern england at t78.

[bluearmy]

I am guessing that maximum is in the netherlands or one of those small countries to the east of France? Imagine how cold It would be here?

It's an easterly so we would be less cold. Irrelevant as it wont be that cold.

[Matty M]

18z showing a better ridge even though conditions seem less favourable around Greenland = confused!

[Snowmadsam]

What is great about this run is the kind of cold uppers shown for next weekend again.....especially after the ECMs wobble this morning

ohhh... :cold:

Ecm was good tonight (I knew it was having a moment this morning I could feel it! ) I am looking forward to what GFS 18 and 00Z say and also the ECM 00z :lol:

If anyone would like to give their brain a rest why not pop into the chat room :- http://forum.netweather.tv/chat/

Edited January 15, 2012 by Snowmadsam

[Cloud 10]

Meanwhile on the 18z,the russian high is reaching out west!

[Cheese Rice]

Much better ridging of high pressure over Russia, pushing further East building heights over Norway. As a result acting as a block for any lows.

!!!!!!!

Edited January 15, 2012 by Cheese Rice