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

[johnholmes]

Last evening I said I would do a more detailed post so here goes. Picking up really on what ba posted above about changes he sees.

 

The 6-10 anomaly charts have differences with one another although the GFS and NOAA 6-10 are more alike than the ECMWF version. They both keep a fairly flat contour flow across the Atlantic. ECMWF looks more like the NOAA 8-14 output.

 

 The question this poses is which version of these charts will be proven to be right. I usually tend to take the NOAA outputs before the other two when there are differences but this is not always the case. Over the past 2 years as each model has been ‘tweaked’ there are a number of times when the EC-GFS outputs IF they are similar show marked wave length changes before NOAA does, be it shortening or lengthening them, and they turn out to be nearer the upper flow in that time scale.

 

Perhaps the differences show over the past 12 hours or so are to do with any colder outbreak being a short lived one. In all honesty I do not know. I would suggest that during the first week of January a colder flow (from the NW) will develop over the UK and western Europe. How long that lasts is probably beyond the ability provided by the anomaly charts. I sometimes look at the NAEFS output and have been known to use the 30 mb temperature chart for some idea beyond the 14 day time scale. Also looking at the GFS MJO output. All these links are given below, apart from the 30 mb temperature chart which I cannot find, but this was posted last evening if you scroll back.

So a waiting game but with some real hope of at least a few days for cold lovers in early 2017.

 

ECMWF-GFS

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

 

NOAA 6-10 and 8-14

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

NAEFS

http://www.meteociel.fr/modeles/naefs_cartes.php?mode=0&code=0&ech=6&map=1&runpara=

 

GFS MJO

http://www.americanwx.com/raleighwx/MJO/MJO.html

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/foroper.shtml

finally found the 30 mb temperature chart

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/

Edited December 24, 2016 by johnholmes

[karyo]

Looking at the UKMO day 7 chart that SS has posted I can see a key difference with the ECM at the same time. The ECM has the high pressure cell further north (Nova Scotia) while the UKMO has low pressure in that area and the high is further southeast.

I don't think the UKMO would produce the northerly so in my view the ECM is on its own this morning.

[Iceberg]

At t168 both ecm and meto have the low in a pretty similar place both with strong ridges and waa infront of them. 

[karyo]

3 minutes ago, Iceberg said:

At t168 both ecm and meto have the low in a pretty similar place both with strong ridges and waa infront of them. 

No, I see it further south on UKMO.

[karlos1983]

5 minutes ago, Iceberg said:

At t168 both ecm and meto have the low in a pretty similar place both with strong ridges and waa infront of them. 

I thinks so. It's not easy to tell from the D7 chart that we have access to now, but at D6 they look in pretty good agreement To my eyes. Granted they are hungover eyes.. 

 

Edited December 24, 2016 by karlos1983

[Iceberg]

No probs I see both in or around the south of Hudson Bay. Largely achedemic though as at that range it will likely change by 500 miles.

[booferking]

GFS moving towards ecm again run by run it will get there always late to the party..

[bluearmy]

Ecm spreads at day 10 show a more amplified cluster and also a cluster edging the upper ridge into Ireland 

 

 

[tinybill]

merry  xmas this  could  be the  xmas present  the coldies will  like  i know  its fi but its looking  good  and it wont happen!!!

Edited December 24, 2016 by Polar Maritime
To save confusion with Formula 1.

[karyo]

7 minutes ago, booferking said:

GFS moving towards ecm again run by run it will get there always late to the party..

Yes, the 6z is slightly more amplified. It should give a decent topler at least.

[phil nw.]

The later 00z gefs are not without interest froom a cold pov as already been mentioned.

A cold easterly on the control run and a decent mean Ht anomaly chart for such a possibility

At least current outputs are trending towards a more amplified NH pattern towards NY so more opportunities for this sort of evolution will show.

[Polar Maritime]

Certainly a better Northerly 'shot' for next weekend on the 6z run.

Also nice to see the Jet further South into the run, Although still powerful.. Pushing colder air over the UK from the N/W under an unstable PM flow.

Edited December 24, 2016 by Polar Maritime

[daz_4]

GFS needs Christmas miracle. It's horrible compared to yesterday and it wasn't even that good to begin with.

[Summer Sun]

27 minutes ago, daz_4 said:

GFS needs Christmas miracle. It's horrible compared to yesterday and it wasn't even that good to begin with.

 

850's never get that high though so often on the chilly side

[TEITS]

Looking at todays output and a few things are clear to me.

What does not seem likely is a sustained block towards Greenland and as a consequence we are unlikely to see prolonged, deep cold. More likely is a 3 day N/NE,ly before turning less cold. At this stage I don't expect much snowfall for my location due to the flow from the N,ly not being sustained enough. However on the bright side the less cold period appears shortived as further cold outbreaks from the N/NW seem likely.

Overall im pleased because an unsettled, often cold start to the New Year is far better than the boring weather pattern we have seen this month.

[tight isobar]

With the current proposed position and 'state' of the polar vortex theres ample chance of decent cold 'shots' given that a pronounced block would ensure stability in a more locked in possible situ.. However again some good opportunity s for comeand go cchance! ...

And that's as it stands some good blocky scenario s are still in some output suites...

[Methuselah]

Has the the makings of one of those messy 'rain, sleet or snow' scenarios, I feel? Still, anything's preferable to hearing weather presenters close with the dreaded 'at least it'll be mild' expression!

[karyo]

Even a sustained northerly may struggle to bring deep cold when the situation in the Arctic is so grim!

http://www.bbc.co.uk/news/science-environment-38417198

[Dennis]

Where will the Azores ridge settle next Year? USA get some new cold too - it could bring this ridge to the north - or it increases the jetstream again.....

Edited December 24, 2016 by Dennis

[bluearmy]

By day 10, the GEFS bias corrected and eps are trending towards each other. Moreso the GEFS although thereafter the NOAA suite trends back to high anomolies to our ne though much less convincing than the 00z run. I would say that the ens seem to have a handle on the envelope out to day 10 and thereafter it's all up in the air (pardon the pun!)

[Gustywind]

22 minutes ago, karyo said:

Even a sustained northerly may struggle to bring deep cold when the situation in the Arctic is so grim!

http://www.bbc.co.uk/news/science-environment-38417198

Surprised it's as warm as they're saying (close to freezing), 850's look pretty cold currently and the polar vortex is stuck over Greenland. Can understand why it was so mild in November and earlier this month, but not now.

[bluearmy]

5 minutes ago, Gustywind said:

Surprised it's as warm as they're saying (close to freezing), 850's look pretty cold currently and the polar vortex is stuck over Greenland. Can understand why it was so mild in November and earlier this month, but not now.

Look at the T2's maxes on the gfsp 00z run n of Svalbard. of course they will change quickly once the ridging moves around but certainly way above where they should be at Xmas. 

[karyo]

4 minutes ago, Gustywind said:

Surprised it's as warm as they're saying (close to freezing), 850's look pretty cold currently and the polar vortex is stuck over Greenland. Can understand why it was so mild in November and earlier this month, but not now.

I was also surprised to see this now but I guess it is the result of a succession of plumes that have reach the Arctic over the last few months combined with the record low ice cover. They even mention the increase of cloud cover which tends to trap warmth this time of the year.

Looking at the arctic ice extent graph, the last few days have recorded losses which is almost unbelievable for December! https://ads.nipr.ac.jp/vishop/#/extent

Karyo

[The PIT]

7 minutes ago, Gustywind said:

Surprised it's as warm as they're saying (close to freezing), 850's look pretty cold currently and the polar vortex is stuck over Greenland. Can understand why it was so mild in November and earlier this month, but not now.

The cold has been displaced elsewhere Sibera, for example and http://www.telegraph.co.uk/news/picturegalleries/worldnews/10552968/US-weather-in-pictures-Polar-vortex-brings-big-freeze-to-North-America.html

Back on subject any sustained cold bar one or two cool days seems off the menu for the foreseeable future.

[Man With Beard]

Is that a fairly strong colder cluster between 2nd and 6th Jan? Also pretty nippy middle of next week.