Model Discussion Thread - 15th Jan

[Liam J]

I don't think anybody needs reminding of yesterdays events, cut the bickering please folks and stick purely to discussing the model outputs.

Think before you post.

Edited January 15, 2012 by Liam J

[phil nw.]

Will some of you stop sniping and spoiling this discussion thread.

We are wasting too much time deleting childish postings-you know who you are.

Edited January 15, 2012 by phil n.warks.

[TEITS]

Blocking to our NE ridging much further W on this run. Only difference is the GFS has the ridge from the Azores much closer whereas the ECM backs this W.

http://www.wetterzen...s/Rtavn1441.png

Edited January 15, 2012 by THE EYE IN THE SKY

[Cheese Rice]

This is what I was stressing earlier. 12Z output at the end of FI is perfectly plausible output, the high can easily build west and acts as a brick wall. Trajectory of lows become more NW/SE and deep cold builds over Norway ready for us to hopefully tap into.

Edited January 15, 2012 by phil n.warks.
i agree but leave it to the team tks.

[chionomaniac]

I would like to have a chance to look at the models myself rather than spend time deleting.

Matty, Peterf, and snowlover2009 consider this a polite request and warning.

[LomondSnowstorm]

18Z decides to cut the northwesterly incursion short with the Azores High becoming more prominent http://cdn.nwstatic.co.uk/gfsimages/gfs.20120115/18/120/h500slp.png

Seems a bit odd that it's moved back to more like what its earlier runs were showing, which tended to be mild outliers at that stage. Still, the Russian high looks to be coming into play in a big way in this run early on http://cdn.nwstatic.co.uk/gfsimages/gfs.20120115/18/138/h500slp.png

[kold weather]

Not looking good on the 18z, that low is undercutting any attempt at ridging towards Greenland, pattern isn't as good as the 12z. FI could yet end up being interesting but a step back from the 18z thus far.

[Matty M]

Blocking to our NE ridging much further W on this run. Only difference is the GFS has the ridge from the Azores much closer whereas the ECM backs this W.

http://www.wetterzen...s/Rtavn1441.png

Ye it's like the GFS is trying to move to a better outcome but the bits and pieces just cannot come together all at once.

The high to our northeast is better build on the 18z but we see the Azores ridge pushing in over us more quickly.

[danm]

Blocking to our NE ridging much further W on this run. Only difference is the GFS has the ridge from the Azores much closer whereas the ECM backs this W.

http://www.wetterzen...s/Rtavn1441.png

Yep, some good some bad from this run. Russian high exerting more influence further west, but azores high sticking further east. Leaves us in no mans land.

[Grimsby Snow Lover]

Despite what the GFS goes on to show us after next Saturday one positive I have found today having just viewing todays models is that the ECM, GFS, UKMO are nearly singing off the same hymn sheet for the next 6 days. Yes there are minor difference as you would expect but gone are the massive differences that were shown between the GFS and ECM of the past 6 days. I will still stress that until the metoffice suggest something with regards to chances of an easterly in the mid range forecast I will not be dusting off the sledge despite what the models show.

[Cheese Rice]

Not looking good on the 18z, that low is undercutting any attempt at ridging towards Greenland, pattern isn't as good as the 12z. FI could yet end up being interesting but a step back from the 18z thus far.

I've never bought the whole Greenland high scenario. It seems our best chance is a high to our NE, the PV is just too strong.

Edited January 15, 2012 by Cheese Rice

[Osbourne One-Nil]

Next person to have a post removed will get a 48hr suspension.

(out of the three mentioned earlier btw!)

[kold weather]

Yep, some good some bad from this run. Russian high exerting more influence further west, but azores high sticking further east. Leaves us in no mans land.

We don't really want the Russian High, we want it placed more to the NE. In the position its in now we really are dependant on the PV splitting, if it doesn't its going to require a very difficult evolution to get cold. it can happen, it happened in Feb 1991 but that took the best part of 20 days to evolve into a positiion where cold could be delivered.

[Kentish Kiwi]

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

That high looks absolutely massive. I mean it stretches from Scandinavia, down to the Mediterranean and right around through Eurasia to Alaska, although the middle section may only be a surface high with low geopotential heights... Nevertheless, high pressure basically covers the entire Eurasian supercontinent.

Is such a feature common at this time of year? It certainly looks imposing enough to impact on our weather.

[PolarWarsaw]

Not liking this evolution if im honest, cold pooling to the NE gets strangled.

[kold weather]

Not liking this evolution if im honest, cold pooling to the NE gets strangled.

Its a step backwards IMO from the 12z, pretty much erases any cold snap. Later on to get cold we need some decent trough disruption, key period for that is between 192-240hrs looking at the 18z, need to watch the Arctic area.

IMO this is a pretty awful run though...

[January Snowstorm]

Funny the way we all take different things from the charts

Whilst thinking the last couple of days runs were poor imo I actually like the 18z

Much better orientated Russian high marching West in the relaible timeframe

Nothing decent showing, but a little upgrade here and there and we could be getting there

As is the situation all Winter that azores high is being a mighty pest

[Cheese Rice]

I'm really excited by the GFS, potential is huge.

I think those focusing on highs building over Greenland will be greatly disappointed as the PV is just too strong. Strat warming isn't displacing the PV, instead creating huge block over Russia.

Look at the cold air building over Norway with heights increasing

Look medium term, not long term. Yes the high isn't strong enough post T150 but the more it builds on each run the less likely it is to flatten.

[TEITS]

18Z NOGAPS shows yet another possible scenario.

http://modeles.meteo...0-144.png?15-23

You know based on the model output these last few days I could suggest many different scenarios beyond +144. However it has to be said im not convinced at the modelling of the 18Z GFS with regards to the Azores HP.

Edited January 15, 2012 by THE EYE IN THE SKY

[bluearmy]

With no troughing to our se, the gfs 18z op is an outlier to all 20 members of the 12z gefs suite by day 7. Bin it.

EDIT: I know there is troughing in the med - I mean there should be a mean trough to our east day 7 .

Edited January 15, 2012 by bluearmy

[Jason M]

Lots of positives here I think. Things don't work out in the medium term, but some signs here of the Azures high getting kicked west as per GPs post.

I'd wager this will end well in FI. The charts up to 120 hours are important IMO, those thereafter less so tonight.

It may go pear shaped tommorow, but were in a better place tonight than we were this morning.

Jason

Edit, LOL flat as a pancake in low res.

Edited January 15, 2012 by Jason M

[Timmytour]

_{I know some of the model runs are showing the chance of an easterly developing some time in the future......and to experience of having some intense cold so late into a relatively mild winter would certainly not be unique.}

_{But anytime it has happened in the past , the preceding weeks of winter have been subject to prior short-lived easterlies.}

_{Has it ever happened before that an almost wholly dominated atlantic driven winter without previous easterlies has gone on to produce an epic easterly?}

_{And if this is indeed as rare as it seems to me to be,....would it be prudent to cast futher doubt on them?}

Edited January 15, 2012 by Timmytour

[kold weather]

Much better orientated Russian high marching West in the relaible timeframe

Nothing decent showing, but a little upgrade here and there and we could be getting there

As is the situation all Winter that azores high is being a mighty pest

The Russian High is a big reason why the Azores High is so strongly present. Whats happening is the PV is attempting to weakly split and fragment, with one lobe shedding off to the east. However the Russian High is too strong and located too far SW and is effectivly blocking its way, so what the 18z does is try and go up and around that upper. This then promotes the Azores high to ridge in as the PV lobe moves NE. Eventually it may go somewhere but it'd be a lnog hard slog. A far better evolution would be fvor a weaker but more northerly placed upper high which would be far more likely to promote trough disruption as the way wouldn't be blocked by the large upper high, thus that would put us into a colder N/NW flow like the UKMO/ECM.

[phil nw.]

Beyond T144 the Scadi trough gets split by the advancing high from the atlantic and all the energy for further trough disruption goes east deep into Russia.

A complete suprise i guess in view of all 12z output which appeared to be ejecting everything south east into c.europe.

As it`s the first run to do this and against all the modelling of the mean trough position we should not take too much notice of the later frames.

Edited January 15, 2012 by phil n.warks.

[Andy_]

A positive from the last two GFS runs, is that the PV is backing comfortably into Western Canada and Alaska, if not still slightly sticking out towards Eastern Greenland and the North Atlantic, albeit in a more weakened state.

Consistency from the GFS is something we cannot ignore, and can be beneficial in the long term

Saying that the 18Z GFS FI is completely opposite (and terrible) from the 12Z

Edited January 15, 2012 by Andy163