Model output discussion - 5th December 2016 - Into Winter we go

[fergieweather]

Notice however how NCEP's parallel 06z suite heads a very different direction, more in keeping with e.g. GloSea's continued - if somewhat less bullish - favouring of the blocky set-up resurrecting after mid-month (a return to blocking also the majority outcome via EPS products using the DECIDER tool run by UKMO).

There remains strong suspicion (and this is an old story) that current GFS remains very prone to going beserk with mobility at longer leads, thus must remain viewed with due caution.

Either way, confidence is of course very low further into the month and we await this evening's EC Monthly update with great interest to see what crossover (if any) it retains with GloSea.

Edited December 5, 2016 by fergieweather

[No Balls Like Snow Balls]

 

[Singularity]

1 minute ago, bluearmy said:

With the environment north and west I doubt it's going to be anything other than a brief amplification of the Euro ridge 

What if it's two rounds of amplification? 

Whereas many on here are searching for HLB as soon as possible, I'm hunting for MLB with the view that it should have plenty of opportunities to reach further north 2nd half Dec... and even if it doesn't I'll appreciate the seasonal temperatures. You'd think having only had one morning of snow in the last three and a half years would make me more desperate yet oddly enough it seems to have made it easier for me to live without it. Though a white Xmas would certainly be a fine feather in 2016's cap.

[Nick F]

With the jet going east under the Scandi high and N then E and SE over the top, you never really going to get deep cold to advect west under it, ideally warnt the jet to be moving SW under the Scandi ridge.

[nick sussex]

With the expected set up at T144hrs you don't want the high ridging north from the south but the ridge to the ne extending sw'wards and being undercut by some shortwave energy.

 

 

 

[Ali1977]

1 minute ago, fergieweather said:

Notice however how NCEP's parallel 06z suite heads a very different direction, more in keeping with e.g. GloSea's continued - if somewhat less bullish - favouring of the blocky set-up resurrecting after mid-month (a return to blocking also the majority outcome via EPS products using the DECIDER tool run by UKMO).

There remains strong suspicion (and this is an old story) that current GFS remains very prone to going beserk with mobility at longer leads, thus must remain viewed with suspicion.

Either way, confidence is of course very low further into the month and we await this evening's EC Monthly update with great interest to see what crossover (if any) it retains with GloSea.

Well, I didn't think we'd get too much hope if Ian did post , looks like not all is lost just yet - v interesting !!

[bobbydog]

1 minute ago, fergieweather said:

Notice however how NCEP's parallel 06z suite heads a very different direction, more in keeping with e.g. GloSea's continued - if somewhat less bullish - favouring of the blocky set-up resurrecting after mid-month (a return to blocking also the majority outcome via EPS products using the DECIDER tool run by UKMO).

There remains strong suspicion (and this is an old story) that current GFS remains very prone to going beserk with mobility at longer leads, thus must remain viewed with suspicion.

Either way, confidence is of course very low further into the month and we await this evening's EC Monthly update with great interest to see what crossover (if any) it retains with GloSea.

Timely back-up to my last post Ian, would you know if the parallel has been performing better than the operational?

[booferking]

2 minutes ago, Singularity said:

What if it's two rounds of amplification? 

Whereas many on here are searching for HLB as soon as possible, I'm hunting for MLB with the view that it should have plenty of opportunities to reach further north 2nd half Dec... and even if it doesn't I'll appreciate the seasonal temperatures. You'd think having only had one morning of snow in the last three and a half years would make me more desperate yet oddly enough it seems to have made it easier for me to live without it. Though a white Xmas would certainly be a fine feather in 2016's cap.

Yea bulldozed out of the way same as the first amplification.

[Paul_1978]

5 minutes ago, No Balls Like Snow Balls said:

 

Deary me Mr Ventrice... a T+360 chart hardly worth the paper it's written on. 

[Singularity]

1 minute ago, booferking said:

Yea bulldozed out of the way same as the first amplification.

Not exactly - chilly continental flow achieved as a result. Another round of amplification approaching... it's not often I say this but that's actually a reasonable suggestion from GEM this evening. 

[Frosty.]

Later on the Gfs 12z becomes more benign with pressure rising across the south with the jetstream shunted further north along with most of the unsettled weather..days become cooler and nights turn cold enough for a touch of frost with mist and fog but it stays breezy and more changeable in the north..this isn't the place to moan so I won't!

Edited December 5, 2016 by Frosty.

[bluearmy]

7 minutes ago, knocker said:

In spades upstrem with the very cold upper trough swinging east across America and the very strong jet. I cannot see anything changing much downstream

 

This uptick in the jet off the eastern seaboard had been well signalled by the models and the eps are undecided as to how strong the northern arm is likely to be and how Far East it can push with gusto.  The runs not too consistent in this regard and as you noted earlier, possible height rise a bit further east in nw Europe could encourage the jet further south (at least some of it via a split flow anyway) 

[Gael_Force]

3 minutes ago, Paul_1978 said:

Deary me Mr Ventrice... a T+360 chart hardly worth the paper it's written on. 

....except it is an ensemble mean and there are no shortwave dramas up there. 

[Methuselah]

Aaaaaaarrrghh! 

I was attempting to post the latest T+384. But, alas, my copy image thingie won't work. Perhaps that's a good thing?

 

[Seasonality]

The parallel run is producing rather different outcomes. A frigid Christmas week on the cards according to the 06z parallel. 

 

[bluearmy]

10 minutes ago, Paul_1978 said:

Deary me Mr Ventrice... a T+360 chart hardly worth the paper it's written on. 

A 10hpa mean chart is fairly decent at day 15 Paul. Things that high up are much more predictable. 

Tough to get a handle on where the centre of the vortex is predicted to be without any spreads though the anomolies are interesting and you could say the upper trough extension also of note 

[Frosty.]

6 minutes ago, Ed Stone said:

Aaaaaaarrrghh! 

I was attempting to post the latest T+384. But, alas, my copy image thingie won't work. Perhaps that's a good thing?

 

It's not as bad as it looks actually Ed

[Paul_1978]

5 minutes ago, bluearmy said:

A 10hpa mean chart is fairly decent at day 15 Paul. Things that high up are much more predictable. 

Tough to get a handle on where the centre of the vortex is predicted to be without any spreads though the anomolies are interesting and you could say the upper trough extension also of note 

Many thanks for that - didn't realise. Interesting stuff. 

[Ali1977]

Even by day 9 the majority of ENS have high pressure ridging back into the UK - could we be about to see a swing back to a dryer cold set up I wonder. 

Infact by day 10 things are really looking up.

Edited December 5, 2016 by Ali1977

[Ali1977]

Snap shot of a few ENS at day 12 highlights what could happen, not all like this obviously 

[Mucka]

GFS output is very poor, no way around that. We have to go into deepest darkest FI to even sniff a few crumbs of comfort.

Better news from Fergie and the MetO long range forecast still favouring blocking even though the signal is seemingly being slowly pushed back toward last 3rd of Dec.

Other than that we have to pin our hopes on any height builds to our N/NE which I first mentioned as being our only potential quick route to a more amplified pattern way back on Nov 30th - nice to see that modeled at least but the signal has never been strong enough to warrant any confidence in it, especially as the models have had the overriding signal being a dominant Atlantic quickly flattening any ridges or fledgling highs.

UKMO has offered most encouragement here on its last two runs but even there it is doubtful we could get the necessary trough disruption behind.

We may have to digest our bland and undernourishing diet of daily patience for a little longer I'm afraid. Oats today, jam tomorrow.

Worth giving the mid term another 48 hours watch though, just in case we get an unexpected turnaround that favours us for once.

 

 

Edited December 5, 2016 by Mucka

[Ali1977]

Yes cherry picked, but this I think is the coldest run this winter season from any Op or ENS.

[knocker]

45 minutes ago, bluearmy said:

This uptick in the jet off the eastern seaboard had been well signalled by the models and the eps are undecided as to how strong the northern arm is likely to be and how Far East it can push with gusto.  The runs not too consistent in this regard and as you noted earlier, possible height rise a bit further east in nw Europe could encourage the jet further south (at least some of it via a split flow anyway) 

And if it doesn't encourage the jet further south I can see another period of ridging to the south west of the UK looming

[Seasonality]

1 minute ago, Ali1977 said:

Yes cherry picked, but this I think is the coldest run this winter season from any Op or ENS.

Hi Ali, which perturbation and what time frame please?

[Ali1977]

1 minute ago, Seasonality said:

Hi Ali, which perturbation and what time frame please?

5 off the latest GEFS extreme FI, but creates a decent Greeny block from day 10

Edited December 5, 2016 by Ali1977