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Model output discussion - 21st Jan Onwards

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2 minutes ago, Nick F said:

Looking at the extended EPS mean and control (to day 15) last few runs, the anomaly signal from them has been for the trop PV to shift east from Greenland into Scandi toward day 15, 06z GEFS mean + a fair number of members been hinting at this and slight hints from the recent high res runs too. So we'd be looking at perhaps a move away from mild SWlys to Pm Wlys and NWlys as we head into begining of Feb. 

This is a move away from the Russian high pushing west into Scandi but never any further west idea.

Be interesting to see if the 12z GFS and ECM continue this theme ... and whether the NOAA CPC 8-14 day anomalies also pick up on this signal too...

Something akin to this perhaps?

gfsnh-0-156.png?12

gfsnh-0-180.png?12

Probably not bad for the ski resorts up here in Scotland (assuming they ain't stormbound) but probably not quite cold enough for snow at lower levels even in the North.

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Very underwhelming GFS 12z so far, the Kara Sea high just a murmur compared to its predecessor.

image.thumb.png.a8acbd6b09f16b57dc2dc1c6image.thumb.png.58636f7599e342084054628b

 

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2 minutes ago, fergieweather said:

Yes, agreed Nick - it'll be interesting to if further support materialises in today's op runs for this. GloSea5 has been repeatedly keen to move promptly away from SW to W'ly, eventually to NW'ly through 1st half of Feb, whereas the last EC Monthly - albeit similar - wasn't eager on the NW'ly component at all, retaining +ve temp anomalies right out into mid-Feb. Interestingly, last night's DECIDER suite started toying with chillier NW-N'ly-fed spell from around 3-4 Feb. 

oh great news,thanks so much for all your updates on the mets models they use,but we cant see :)

 

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12 minutes ago, Earnest Easterly* said:

Very underwhelming GFS 12z so far, the Kara Sea high just a murmur compared to its predecessor.

image.thumb.png.a8acbd6b09f16b57dc2dc1c6image.thumb.png.58636f7599e342084054628b

 

On the other hand its movement toward Svalbard is good for interfering with the vortex.

The chart on the right sums up the situation pretty well as we end the month; the PV is split between two major segments and we want the one over Canada to move toward Europe. There is plenty to suggest that it will do so, but we need to see any remnants over Canada dealt with. This is where the tropical forcing comes in. Until GEFS adjusts its outlook in that respect, it will struggle to remove the Canadian vortex segment at the surface even as it vacates from that area in the stratosphere.

 

Oh and has it happens, a side effect of the adjustments to AAM should be a reduction of the Euro Ridge and increasing tendency for it to draw west into the mid-Atlantic, which means we must sacrifice further drier, calmer weather for wet, windy conditions as a means to getting the colder conditions down the line. No pain, no gain I'm afraid!

Edited by Singularity
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14 minutes ago, Ravelin said:

Something akin to this perhaps?

Probably not bad for the ski resorts up here in Scotland (assuming they ain't stormbound) but probably not quite cold enough for snow at lower levels even in the North.

Yes, you can see from the 12z GFS op, like the 06z, veering the flow more westerly as the low heights spread east from Greenland and through to Scandinavia. The big 850-500mb cold pool over NW Russia + far NE Europe actually joins the cold pool spreading out from Greenland, maintaining the westerly flow with Pm incursions, helped by a strengthening westerly jet stream too, so some cold zonality possible for the north at times ... good news for the Scottish ski industry, though there is the risk of some nasty deep depressions with such a set-up too.

Edited by Nick F
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16 minutes ago, Singularity said:

12z +240: gfsnh-0-240.png?12 06z +252: gfsnh-0-264.png?6

Considerably better than the 06z in the Arctic with a high right by the pole and the vortex even more manged. The jet has also trended south - the very start of the trend expected as the support that GEFS thinks the subtropical ridging will have is (slowly but surely?) taken away.

I can see how lows developing off the East U.S. and bombing out (potential Nor'easters for them) could be a pain for a time, though without such deep cold over the U.S. this season I expect there's a greater chance of them being weaker and more prone to disrupting against the rising heights in the polar regions.

 

gfsnh-0-276.png?12

Yeah... my advice is to take this chart and reduce the heights to our south while increasing them to our north, while adding a negative tilt to the trough SW of Greenland. Not saying we'll get there that fast (though we certainly could), but that's where I believe we should be heading with time.

Great posts Singularity. Are you GPs love child?  Is torpedo your code name? 

Joking aside. You seem pretty confident that the GFS cannot handle the mountain torque influence on the AAM, how do you feel the ECM handles it? 

Should we expect the ECM to pick up more amplification in the Atlantic before the GFS

 

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18 minutes ago, mountain shadow said:

Great posts Singularity. Are you GPs love child?  Is torpedo your code name? 

Joking aside. You seem pretty confident that the GFS cannot handle the mountain torque influence on the AAM, how do you feel the ECM handles it? 

Should we expect the ECM to pick up more amplification in the Atlantic before the GFS

 

Thanks for the kind comment (and same goes to blizzard81 for earlier) :)

To the first question, as far as I know I'm not :laugh:. Nah but I know I'm not don't worry GP!

Second one is definitely not the case although yes I have been in support of the idea... latest landing date he offered was 28th Jan so a week from today. Currently that appears a tad fast but we can't assume too much with the model output at the moment.

Third question, I wish I could see what ECM does with the AAM on a GWO plot as that would provide some answers. However I have got the impression over the years that it handles it at least a little better than GEFS, though it's hard to be sure due to the amplification bias in certain parts of the Atlantic and European sector that may or may not be related to errors with AAM prediction. There's too much secrecy this side of the Atlantic! :nonono:

 

I think the 12z GFS has delivered the best det. effort in a while from the model, in that the jet trends ever further south and we start to see the anticipated dig of low heights into Europe. From the +384 hour chart it looks good for that next low from the west to merge with the one to our east and bring some cold air our way - and that's even with those lows being rather too close to bowling balls in nature!

Hah - just read Fergie's last post. Judging by that ECM monthly outcome I guess it struggles with the tropical forcing as much as GEFS in the longer term. Either that or all this theoretical science is for nothing - but given the behaviour of the Met Office's key ensemble based models, I doubt it.

Edited by Singularity
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Previously I posted about the models likely moving away from an Easterly and instead building an Atlantic ridge around end of January.

I think we have seen the models move away from the Easterly but not yet showing any propensity for upstream amplification.

However yesterday morning (I think) I posted a GFS chart showing high pressure at our latitude from the Atlantic to Russia - possibly the most unappealing chart I have seen this year - but stated I thought that was quite wrong and the models would begin to drop pressure over Northern Europe instead and again I think that is likely to be the reality.

Taking those two thoughts together it looks like I am going to be wrong about an Atlantic ridge given the current state of the ensembles but on the right track with regard to the output moving away from a block to our NE and being more favourable than was being shown in that heights should begin to fall to our South.

There is little sign that the models want to drop a trough into Europe around day 9/10 currently and also little sign of worthwhile upstream amplification.

The Azores high looks to be stubbornly fixed and we need it displaced West.

I'm not calling it a bust yet but I had hoped to see a  genuine signal for the Azores high being displaced and more sustained pressure drop over N Europe. 

Things have definitely not gone to plan in model output land so far but then they aren't always right are they?

Let's hope they are missing something here because they are moving toward a zonal start to February.

Edited by Mucka
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Anoms show a decent signal for Arctic heights.

gensnh-21-5-300.png

Edited by SN0WM4N
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3 minutes ago, SN0WM4N said:

Anoms show a decent signal for Arctic heights.

gensnh-21-5-300.png

Just a sniff of a rerun of earlier in the month here - heights get into the Arctic via WAA directly over us, then as the PV swings round they get stuck and swing back round towards us. That's the theory - nowhere near close enough in time to base a forecast on that. 

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Well the potential long shot easterly looks way to far east tonight, however, as mentioned by Ian and others a north west/northerly flow could be in the making. With the PV transferring from north west to east.....I rekon that Azores high is ripe for some strong ridging. One to watch.

 

Rtavn2161.gif 

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Evening all :)

A couple of days away from the model output and some significant changes to my eye with new signals pointing perhaps to a mobile W'ly or even NW'ly regime from the turn of the month. Possibly not the best for the flooded areas which might be facing a renewed onslaught early next week.

The HP seems to have been displaced from Europe to the north of the Azores which is a small positive step and the PV remains under a lot of pressure with quite a few of the GFS members showing it being fairly well shredded into FI. Not a lot on which to hang hopes but perhaps some baby steps in the right direction and I don't worry much about the ability to catch a decent cold in late February or early March. 

As ever, more output is needed...

 

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11 minutes ago, mb018538 said:

Sorry, but I think all of the models have handled this hideously badly. A few days ago we were looking at a nice dry spell with a large high slapped over or very near to us. At least this was going to dry things out...

Well today we have been left with:

Rtavn19215.gif

 

An awful, flat, powerful & zonal W-E jet, plenty of low pressure, wind and rain.

Rmgfs144sum.gif

Close to 100mm of rain in the next 6 days across Cumbria again.

Tearing my hair out! It's like a diet version of December!!

Since its been handled so badly who's to say that in a few days time it won't look completely different again,  and those charts you show of 8 and 6 days out will be different? Looking nothing like December, not yet anyway. 

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In the absence of anything remotely wintry from the main Op runs I think I'll place my order for P7 from the GEFS

gens-7-0-264.png

gens-7-1-264.png

Trouble is even then a day later we get this - MILD SECTOR ALERT!

gens-7-0-288.png

At least the GEFS do go cooler or just back to average at the end of the run

MT8_London_ens.png

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Last chart of ECM, notice how the vortex and low heights over Greenland have shifted east. Could be where we're potentially heading down the line...

image.png

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The 264 chart would be nice I'd imagine. It would be nice to see the heights shown at 240 around the North Atlantic to still be showing in the later time frames of the run come the 00z. 

There is still hope after all......perhaps

image.png

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Well as it gets into the higher resolution, I very much doubt that it will now flip on all 3 big models and develop a large anticyclone! Rainfall spikes are starting to show on the ensembles too.

Its certainly not December, but as I said, a watered down version for now. Every day here for the next 10 days is forecast to reach 10c or above. I wouldn't say that's far off!! It's miles above average!

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I agree the Ecm 12z NH profile looks very encouraging for coldies from T+240 onwards with the seeds of a strong polar / arctic maritime blast in development..i will take any crumbs of comfort that are offered by the models and the 12z output is better for coldies potentially!..:D:cold-emoji:

npsh500.240.png

ecmt850.240.png

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12 minutes ago, tight isobar said:

@purga that perturbation "7" is the twin brother of the operatianal gfs 6z'..showing almost exact "synoptics" @easterly...Anyway distant memories it seems. .the 240 ecm continues to note the large mother lobe vortex eyeballing an eastwards evolution' and again the kara high sharpens its knife with another shown sharpening of height at Western flank usa/Canada. ...im personal looking for thw the split between the two via part or complete link up..then focus on any waa taking advantage! 

Can't post charts from meteocial??!!

gfs-1-234.png

 

ECH1-240-2.gif

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