Model Output Discussion 1200 hrs 30/09/14

[knocker]

A general look at the GEFs and ECM anomalies this morning at days 120, 240 and 360.

 

At 120 good agreement with a Nor'easter east coast of America, build up of heights Greenland and Canada, ridge mid Atlantic and trough NW of the UK and a meridional flow. Some dodgy wet weather. All change at 240 with a flattening pattern upstream and a large trough area from the pole, Greenland, UK and Europe leading to cyclonic cooler air dominating the eastern Atlantic, Wet and windy over the UK in the more zonal flow  as the jet moves a tad south. At 360 there appears to be some suggestion of retrogression of the HP in the east. Also some suggestion of the PV getting up a slight head of steam.

Edited October 28, 2014 by knocker

[carinthian]

The latest 06z GFS shows some unusual synoptics. Not very often you see a developing cold pool over the British Isles but hints at that at the end of the run over SE Britain. Long way off, but could be the trend we cold lovers are looking for.

C

[legritter]

The latest 06z GFS shows some unusual synoptics. Not very often you see a developing cold pool over the British Isles but hints at that at the end of the run over SE Britain. Long way off, but could be the trend we cold lovers are looking for.

C

Yes looks good ,but at this range as usual all subject to change .overall the further outlook this morning looks good with some action weather about .If Mother nature is going to balance out the temperatures before the end of this year it could be very interesting ,A big Straw but im going to give it a try .ECM  certainly showing some nice charts as we enter November ,cheers gang .

[IDO]

The latest 06z GFS shows some unusual synoptics. Not very often you see a developing cold pool over the British Isles but hints at that at the end of the run over SE Britain. Long way off, but could be the trend we cold lovers are looking for.

C

 

 

Yes the early bird pub run, the 06z. Well the op at D15:   Mean: 

 

There are a few members in the GEFS that support this, but it looks like typical 06z output and not to be taken seriously. Another member has a stunning chart:

 

  

 

But that is just as likely to not happen. The GFS op looks an outlier on the temp graph: 

 

Have to see if the 12z supports this run 

[Barry12]

If the GFS 12z is anything like perturbation 17 it would be amazing, unlikely but possible

[phil nw.]

Definite indications that we will drift towards a colder feel to things as we go into the first week of November when looking at the 2M temps. mean chart in i'm dreamings... post above, and in the other earlier outputs from the 00z runs.

 

A look at the days 5,10 and 15  naefs 850hPa anomalies show the erosion of the warm uppers towards average and rather cold by day 15.

 

 

this trend also showing the combined ens temperature graph

 

we can see a noticeable step change downwards in the early days of the new month on that graph.

 

A sign of a somewhat colder Atlantic pattern to come compared to our recent mild,almost balmy feel to the air.

 

Still unsettled and westerly driven but the likely hood of the jet meandering further south at times allowing the winds to turn away from the current more southerly quarter to a colder north Atlantic source.

 

Nothing out of the ordinary for late Autumn it should be said but perhaps with more noticeable incursions of polar maritime air especially further north where we should start to see Highland snowfall from time to time.

Edited October 28, 2014 by phil nw.

[nick sussex]

It's somewhat a case of model musical chairs at the moment.

 

Last nights ECM  was dropped this morning only to be taken up by the GFS 00hrs and 06hrs, the models seem incapable at the moment of finding the correct solution for the ne USA and western Atlantic.

 

Theres always the possibility of something colder when you have the PV located to the ne rather than as we often see stuck over Greenland.

 

Interestingly for down here its been the warmest and driest October since 1921,  that was followed by a very cold November, not sure we have the right background conditions for a similar repeat but at this stage even average temperatures here would feel much colder.

Edited October 28, 2014 by nick sussex

[knocker]

Yes GEFS has it a bit cooler by the end of the run but still around average and some quite warm air to the east.

 

[Barry12]

GFS has got rid of it's Northerly it had on the 00z and 6z

 

Edited October 28, 2014 by Barry95

[IDO]

GFS has got rid of it's Northerly it had on the 00z and 6z

 

 

 

Yes no surprise there. It had little support.  Several of the US weather commentators have been suggesting that GFS this morning had got the upstream pattern  very wrong and after the 12z they still suggest it needs to move a little bit more (too amplified). They have been suggesting UKMO has lead the way with ECM following this morning. Day 6 UKMO:

 

Edited October 28, 2014 by i'm dreaming of...

[Barry12]

The whole of the GFS 12z is so boring, the coldest it gets is -2 uppers. GFS has been poor the last few weeks, ECM much better. I think the first half of November can be written off.

Edited October 28, 2014 by Barry95

[Cheshire Freeze]

GFS moves the PV into its favourite abode into FI

 

 

 

An uninspiring GFS 12z in all honesty

Edited October 28, 2014 by CreweCold

[Newberryone]

GFS moves the PV into its favourite abode into FI

 

 

 

An uninspiring GFS 12z in all honesty

Can we assume so that IF the PV does relocate to that position, that we can expect to see a far more active Atlantic affecting many parts of Northwestern Europe?

[Ali1977]

As mentioned above, not the best GFS from a coldies perspective, however remember this is still Oct.  If it wasn't for our early cold in 2009/10, or the awful warm and wet 2013/14 season then no one would be overly bothered at this stage.  The difference between back to back GFS runs prove it's struggling to deal with the changes such as a strengthening PV, or influences from our very good NH snow cover that are known to effect winter weather patterns,

Hopefully in a week or so some of these will be modelled slightly more consistantly, giving us a clearer idea on where we are heading in the medium term.

[Cheshire Freeze]

Can we assume so that IF the PV does relocate to that position, that we can expect to see a far more active Atlantic affecting many parts of Northwestern Europe?

 

We'd like to avoid it really. We all know how long that PV can sit spinning in that location. The issue is that if you look back at years like 09'/'10 the PV struggled to settle in any one place and there were wedges of Arctic heights meandering around.

 

Nov 2009.....unsettled for UK but notice lack of vortex to NW

 

Edited October 28, 2014 by CreweCold

[Cloud 10]

Surprised there's been no mention of the 12z UKMO.....

 

 

 

[shaky]

Surprised there's been no mention of the 12z UKMO.....

 

UN144-21.gif

was gona say the exact same thing an hour ago!!looks much more interesting!!pretty sure we would see some of undercut under the greenland ridge setting up a northerly in the next frame!!!Although it maybe short lived it looks better than the gfs!!!lets see what ecm brings!

[karyo]

Very grim NAO forecast! http://www.atmos.albany.edu/student/macritch/naoindex.png

 

Once the pv settles around Greenland not many things can move it as we saw so many times before.

 

Karyo

[Barry12]

UKMO 96 vs ECM 96

 

 

 

UKMO 120 vs ECM 120

 

 

They look very similiar, possible Northerly incoming on ECM?

Edited October 28, 2014 by Barry95

[Barry12]

Hmmm...

 

[shaky]

Didnt expect this at 144 hours!!defo thrown the cat amongst the pigeons........

[Captain Shortwave]

The GFS does appear to be exploding the Greenland area into life with low heights from the start of week 2. The GEM and ECM don't really want to do this and continue to keep the main lobe of the polar vortex over the Siberian side. As for the northerly, hmm the ECM looks very dubious and the GEM never really gets the cold into the UK so an outside chance of a cold shot but in reality I think we will just keep a changeable westerly flow, no major zonal or cold spell in my opinion.

 

Again worth noting that 20C could be reached on Thursday, Friday or Saturday this week with 21C possible on Friday with the 12C isotherm plastered over centra/southern England again. The caveat being sunshine amounts of course.

Edited October 28, 2014 by Captain shortwave

[gottolovethisweather]

Surprised there's been no mention of the 12z UKMO.....

 

UN144-21.gif

 

I thank you for highlighting this Cloud 10, as the 3rd and 4th November timeframe, for me, has intermittently be shown to be one of interest for at least a brief snap of something much cooler  for once.  No more, no less, but a trend is a trend is a trend. Will wait until the end of the month to see if it sticks to this as we enter t-72 hours! 

Edited October 28, 2014 by gottolovethisweather

[SMU]

I think some people here to recall how poor the GFS is in semi blocking conditions, The operational run, the Enesmbles have all looked dire for the past 5-7 days but ever so slowley the cold is starting to dig ( in the mid term ) into the UK, but the GFS still doesnt see it- espeically the 12z Operational.

 

If you look where the JMA & the EXM have the vortex around 192 & then compare with where the GFS 'wants' to put it- then theres your answer.

 

Make the most of the warm southerly winds....  Cold Wet & windy will sum up the first week of Novermber..... -

The persistence of the increased heights over greenland is really making the forecast difficult, however as ever the euros will have a better grip on it & the GFS will be flapping around-

 

where is the GFS is the current day 5 & 6 League table?....

 

S

[IDO]

No real cold on the ECM so the most interesting chart is for Friday: 

 

The uppers for late in the run mainly around average: 

 

D6:   D9:  D10: 

 

On this run the US (again) getting a deep trough with very cold uppers: 

 

They are carrying on from last winter hopefuliy we won't