Model output discussion - 1st December onwards

[blizzard81]

2 minutes ago, nick sussex said:

You're welcome.

Certainly the postage stamps should give us an idea of what that shortwave might do. They used to go upto T168hrs but ECM got stingy!

Ha ha, yes I remember when they changed how far they went out. Will be keeping a close eye on these. Cheers

[Man With Beard]

Well nice to see some divergence at a short timespan - whilst uncertainty is on the air, the chance of a break from this pattern remains alive. 

The eye catching GFS clearly at the far end of what could happen as a result of the Scandi block, but entirely consistent with the possibilities that have existed for a few days now, due to the height rise to our north. 

In a situation like this, where the PV has been so dominant, you have to lean more to the ECM solution which pushes the block east quite quickly, but my friends we are not a million miles away from this back door easterly becoming a reality, a tweak here and there and it may be on. Odds around 80:20 against at the moment though.

Still, at last something different to watch out for!

[Cheshire Freeze]

Looking at the modelling I think it's safe to say we're at a tipping point- very finely balanced- as to whether we see any mid term cold from that pressure rise to the E. ECM seems to have wobbled slightly towards a more GFS type set up with literally ANY more energy heading under the block and we'd have seen a similar outcome to GFS. I suspect modelling will be erratic over the next couple of days due to the nature of the beast (if you'll excuse the pun). The NWP is notoriously bad at a) getting a handle on correct pressure profiles to the E/NE when dealing with a block and b) the separation of jet energy and how it then behaves as it encounters any blocking. Potentially a forecasting nightmare coming up.

Either way, I suspect this is just the curtain raiser to a more conducive NH set up over the next 4-5 weeks. More opportunities like this could pop up out of the water at relatively short notice.

P.s those circling sharks are getting closer to their meal

 

Edited December 24, 2015 by CreweCold

[dragonfalls]

Merry Christmas to all do u think a block is building for some cold later in Jan Feb something afoot

[legritter]

Good evening all and merry christmas to you all .I,m very happy with current charts etc ,plenty to keep us interested and plenty of scatter about which i like to see .

not so good this evening for people prone to flooding ,and later next week looking very disturbed ,good eye candy with high pressure to our east and north east and we all know how these highs can be hard to forecast .

talking of fax charts i think they are a thing of beauty ,but with so much detail especially at the 4/5 day range each publication will vary alot especially during current synoptic situation .

so at this stage it looks a fair bet that some could see something wintry later next week and start of new year as some good 850 s temperatures get in the mix .

Perhaps santa can arrange for a nice block to set up to our n north east ,cheers to you all ,fantastic Lunar Halo currently and a nice hail shower today  winters on its way ,poor daffis  

 

[Paul White.]

Joe b has been tweeting about the mjo 

 

no idea what that means for us in uk. But sounds interest.

[A.J]

25 minutes ago, Greenland1080 said:

Mods are the reigns loosened for 24 hours...posts slightly more flexible in the mod thread.....Like the 1927 Xmas day blizzards

 

No.......Never!............bah humbug

[Ice Day]

2 hours ago, CreweCold said:

The thing is Nick, even when you look at something like the ECM solution you can't help but feel it's a matter of time before we could get in on winter. Even if you take the day 10 chart, that's not a sustainable pattern for mild (like we've seen throughout December) so I'm fascinated as to where we head through January!

Totally agree with all of that CC.  

Well today has certainly awoken me from my early winter hibernation!  What's really stood out is that there are some big changes suddenly showing in the semi-reliable time frame.  Example, this is at 192 which, whilst very good in it's own right, is only a smidge away from being something quite extreme.

I think a Christmas Eve spectacular could be on the cards for the 18z.

Finally, just to echo Frosty's earlier post.  Happy Christmas to everyone, but especially the mods of this fine site; it gives us sad weather geeks somewhere to exist with like minded saddos!!!

 

 

[bluearmy]

Pleased to see that very few are getting over excited by the over progressive ( blocked) gfs output 

as as some are pointing out, the ECM op is also throwing out some interesting hemispheric fi output and if we have enough patience, I think we will be rewarded next month. 

[Tim Bland]

More support from the ensembles on 12z GFS compared to 06z. Definitely a significantly cooler start to 2016 than we  have been used to!

 

 

[Due South]

Check out where the MJO is going #PartyTimeFolks

[Grimsby Snow Lover]

Let me guess... Number 7 by any chance?

[knocker]

Time to sit back for a little reflection methinks. The set up is so mobile at the moment and to say the least the day to day outputs are so volatile is an understatement so one is in danger of not seeing the wood for the trees, or even the daffodils. So what is the upper air telling us in the shape of the anomalies?

Well at T240, although not in complete agreement they are on the same page and this does indicate a pattern change. Upstream we now have the vortex N. Canada with a trough running down the eastern N. America dragging some cold air down to displace the extraordinary heat possibly an indication of a positive PNA,, as well as the ridging into Alaska. Downstream a negatively tilted trough Greenland to Scotland with a ridge of varying intensity NE Europe with no sign of blocking. This would indicate a westerly regime with periods of unsettled weather, particularly in the north with temps a tad above average in England,

Now what of the evolution from here through the ext period. Well the two differ. They both agree on the vortex N. Canada and a trough in the western Atlantic but whereas the GEFs has a rather nondescript area of HP to the east the ecm has a trough running down through Scandinavia to eastern Europe with HP nudging up from the south. I'm rather inclined to go with the latter. So still in a W/SW regime with temps around average and possible some more settled weather especially in the south.

So the pattern change wouldn't appear, as yet, to significantly change the outlook for the UK.

 

Edited December 24, 2015 by knocker

[knocker]

Today's temp anomaly chart shows the extent of the remarkable heat in eastern N. America.

[Cheshire Freeze]

Jet not splitting as favourably on this run which means the first round of low heights trying to dig south is not materialising as it did on the 12z. To be expected though as it's a finely balanced situation.

[Midlands Ice Age]

On 12/20/2015 at 10:34 PM, feb1991blizzard said:

7 minutes ago, knocker said:

Today's temp anomaly chart shows the extent of the remarkable heat in eastern N. America.

 

Knocker.......

Things could be about to change over there.....

[bluearmy]

1 minute ago, CreweCold said:

Jet not splitting as favourably on this run which means the first round of low heights trying to dig south is not materialising as it did on the 12z. To be expected though as it's a finely balanced situation.

I would say it's to be expected because only one out of 51 ECM ens members predict it Crewe!  GFS a day behind the GEM whilst the GEM has already caught up with reality today. 

[Cheshire Freeze]

1 minute ago, bluearmy said:

I would say it's to be expected because only one out of 51 ECM ens members predict it Crewe!  GFS a day behind the GEM whilst the GEM has already caught up with reality today. 

Fair enough! Still, that's some decent Russian cold...

 

 

[Carlrg]

That easterly is slowly showing its hand on the GFS18z.

 

[Cheshire Freeze]

We may miss out on an easterly but still, you'd think all of that WAA straight into the Arctic will not be without consequence down the line...

 

[bluearmy]

8 minutes ago, CreweCold said:

Fair enough! Still, that's some decent Russian cold...

 

 

 

The WAA into the Arctic will be the real Xmas present Crewe.  Of course the Russian cold is a consequence of that WAA.  

[forecaster]

The newest EC32 has come through, and there are no explicit changes. Still westerly and mild till the end of January. The t2m warm anomaly seems to be a little stronger and larger over Europe than in previous runs.

[Cheshire Freeze]

1 minute ago, bluearmy said:

 

The WAA into the Arctic will be the real Xmas present Crewe.  Of course the Russian cold is a consequence of that WAA.  

Yes! See my post above

[Mucka]

We all got so excited by the GFS 12z we forgot about the parallel run.

Doesn't quite make it but wow what an FI, absolute snowfest.

 

 

Just for Xmas fun of course

Edited December 24, 2015 by Mucka

[igloo]

everything is slowly moving further east on the GFS as most people expected would happen a near miss a big new year storm looks more and more likely with each run