Model Output Discussion 1200 hrs 15/11/14

[Polar Maritime]

If you find your post is missing it's been moved the the Model/moan/ramp/banter thread. Please stay on topic which is Model 'Output' Discussion, There are other threads for historical charts and pattern matching. And please try and avoid one liners.

 

Thanks, PM 

Edited November 29, 2014 by Polar Maritime

[gottolovethisweather]

I know I have highlighted this link before but it is really worth people viewing all the projected surface condition (Fax updates) options together as things might yet change with regard to where the HP resides in relation to the UK even early into next week.

 

http://www.weathercharts.org/ukmomslp.htm

 

Especially having viewed the latest GFS P, I am not so sure that there isn't less oomph in the Azores High and more impetus coming from the continent into parts N and NE of the UK. Broadly speaking however, next week will be generally chilly and dry for most of us with daily variation in cloud amounts. 

Edited November 29, 2014 by gottolovethisweather

[bobbydog]

If you find your post is missing it's been moved the the Model/moan/ramp/banter thread. Please stay on topic which is Model 'Output' Discussion, There are other threads for historical charts and pattern matching. And please try and avoid one liners.

 

Thanks, PM 

Hi PM, perhaps i should have been less subtle with my question. The (purportedly less reliable) 06z GFS op is apparently showing a "Bartlett" high pressure scenario. I would invite any of our more learned members to explain if this model run is indeed showing a "Bartlett" and if this is a viable solution from the current set up. Thanks in advance.

Edited November 29, 2014 by Polar Maritime

[492]

http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

 

Models seem to mostly agree on low pressure to the south over the next few days with ridging over the middle of the country and a gradual cooling trend with a frosty spell next week for parts of the UK. There is evidence of a cold pool east of Poland which could eventually become absorbed by the low now moving NE into the Med and with some remarkably high temperatures over the western Med there may be potential for invigoration of this low. Also of note are observations of blowing sand over N Africa which could get sucked up and blown above the UK giving the sky a milky appearance over the next few days. At the same time the colder drier air is creeping ever closer to the south east with most of Holland now in this colder air. The high over NW Russia continues to be maintained and has moved further north over the last couple of days. Also note worthy is that the Russian high is not that intense at around 1040MB. Intense highs can look dramatic but sometimes can be prone to quick displacement where as more modest highs can hang around for longer periods.  

[IDO]

Just want to highlight the above post from Fergie last night which some may have missed. The pro's at the met did not agree with their own model last night which means they didn't agree with the ECM either. You could see this when the modified fax charts came out last night - they made much less of the low pressure over southern Europe and placed more emphasis on the ridging from the azores. This is the interesting bit though - the updated modified fax charts this morning have done an about turn. They now agree with lower heights over Europe with the azores ridge much less prominent. It looks like the met should have stuck with their own model and ECM last night.

 

The T120 FAX will not get updated till tonight so I don't have a point of reference to compare. The problem is that although there is a very small cluster at around D6 for a more amplified Atlantic ridge towards Greenland, even these GEFS  within 24 hours model that ridge to be overrun from energy from the Canadian PV. The 3/4 GEFSs that are close to the UKMO take, all topple that ridge. We have seen the ECM do exactly that at D7-8. The PV is on the move so I cannot see the UKMO D6 chart go anywhere cold.

 

As for the GFS 06z run that also shows a continuation from the 0z model with the PV energy moving east in week 1 and moving back west after that; the second run with this pattern. The op. P & C all show this. The problem with this outcome is that it makes it much less likely for heights to build towards Greenland and with the Azores/Atlantic pushing SW to NE we get into a more TM flow:

 

Mean 850s at D14:  

 

Very little sign of anything promising from the GEFS on the 06z and hopefully not a step backwards.

Edited November 29, 2014 by i'm dreaming of...

[knocker]

http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

Also note worthy is that the Russian high is not that intense at around 1040MB. Intense highs can look dramatic but sometimes can be prone to quick displacement where as more modest highs can hang around for longer periods.  

Well 1040mb is pretty intense in my book.

 

 

Intense highs can look dramatic but sometimes can be prone to quick displacement where as more modest highs can hang around for longer periods.

 

Why is that as it seems counter intuitive?

[Barry12]

IDO, both the UKMO and ECM disagree with the GFS. Also NOAA have discarded it. If the GFS is right I will run around central London naked.

[carinthian]

http://meteocentre.com/analyses/map.php?lang=en&map=eur_full&area=eur&size=large

 

Models seem to mostly agree on low pressure to the south over the next few days with ridging over the middle of the country and a gradual cooling trend with a frosty spell next week for parts of the UK. There is evidence of a cold pool east of Poland which could eventually become absorbed by the low now moving NE into the Med and with some remarkably high temperatures over the western Med there may be potential for invigoration of this low. Also of note are observations of blowing sand over N Africa which could get sucked up and blown above the UK giving the sky a milky appearance over the next few days. At the same time the colder drier air is creeping ever closer to the south east with most of Holland now in this colder air. The high over NW Russia continues to be maintained and has moved further north over the last couple of days. Also note worthy is that the Russian high is not that intense at around 1040MB. Intense highs can look dramatic but sometimes can be prone to quick displacement where as more modest highs can hang around for longer periods.

Its just great watching the weather unfold presently in Europe. Sub fridged surface air crossing into East Germany from Poland and even the Hook of Holland only a few degress above freezing.

Sub tropical air mass still in much of France and into southern England now. So quite a contrast presently. Will be quite a shock for those in the SE on Monday as they pick up a much colder surface flow. A strong to moderately baroclinic sub tropical jet lay to the S and E of the Med low now forming will help to maintain its influence into the middle of next week with a associated trough probabale to the north of the Alps .

C

[blizzard81]

The T120 FAX will not get updated till tonight so I don't have a point of reference to compare. The problem is that although there is a very small cluster at around D6 for a more amplified Atlantic ridge towards Greenland, even these GEFS  within 24 hours model that ridge to be overrun from energy from the Canadian PV. The 3/4 GEFSs that are close to the UKMO take, all topple that ridge. We have seen the ECM do exactly that at D7-8. The PV is on the move so I cannot see the UKMO D6 chart go anywhere cold.

 

As for the GFS 06z run that also shows a continuation from the 0z model with the PV energy moving east in week 1 and moving back west after that; the second run with this pattern. The op. P & C all show this. The problem with this outcome is that it makes it much less likely for heights to build towards Greenland and with the Azores/Atlantic pushing SW to NE we get into a more TM flow:

 

Mean 850s at D14: gens-21-0-336.png gens-21-1-336.png

 

Very little sign of anything promising from the GEFS on the 06z and hopefully not a step backwards.

In relation to the fax charts, I was referring to the conditions in our locale as opposed to the amplification downstream.

[492]

Well 1040mb is pretty intense in my book.

 

 

Why is that as it seems counter intuitive?

It is something that I have noticed over many years. Not always the case though...a couple of winters back a high of 1060MB gradually moved westwards from Siberia at around 60 N putting most of Europe and SE UK into the freezer and lasted around a week.. reasonably well modelled though. I think that the more intense the high the more energy is required to maintain it so although the pattern is more likely to be meridional for intense highs to exist the chances are that the lows are also highly intense and the highs can get quickly shunted away.   

[Snowman.]

6z in FI just blows up the vortex which we all know it loves to do.

 

It's twin however doesn't do this and still keeps a lid on the PV and Arctic heights and the PV remain distraught and disrupted.

[chionomaniac]

Some great volatility in model output from suite to suite at present, Indian Ocean MJO is mixing things up. You can read more about the MJO in the excellent link below from Kyle McRitchie.

 

Differing solutions from GEFS and ECM on how far this current event travels across the Pacific, thereby imprinting onto the atmosphere. UKME guidance does not go out as far as what we have available from ECM / GFS on the CPC site.

 

GFS

NCPE_phase_21m_small.gif

 

Note the high amplitude and also the progression through to phase 8.

 

UKMO / ECM

UKME_phase_23m_small.gifECMF_phase_51m_small.gif

 

ECM less keen on this eastward progression across the Pacific.

 

Courtesy of WSI this next image shows the location of MJO / KW ( Blue) with a handy view of the Pacific Basin so you can see the MJO direction of travel. Indian Ocean > Maritimes > West Pacific > Central ( Fade) into origin or what is referred to as COD ( Circle of Doom)

B3kfM3PIAAALjVK.png

 

So, we have phases 6-7-8-1 projected by the models.

 

From the Cassou paper here are the leading modes affecting Europe in each phase, have annotated where we are just now and going forward into December, there is no definitive dividing line generally each phase imprints within 6-10 days, bearing in mind the MJO travels slowly eastward where other components in the MJO signal move more quickly, so you may see on the modelling a blend of the composites or trending from one phase to the other.

MJO.JPG

 

Phase Plot Composite Anomalies for each of the phases

 

December Phase 6 Phase 7

December Phase 6 All Amp.gifDecember Phase 7 All Amp.gif

 

December Phase 8 Phase 1

December Phase 8 All Amp.gifDecember Phase 1 All Amp.gif

 

So, the question today -  is the MJO a little fast on GEFS due to the CCKW imprinting on the MJO diagram, or is GEFS suite correct and the ECM is yet to catch on and further amplify as it then sees Phase 8-1 also. Will be a good watch for the next week or so, Phases 8-1 really do herald fun and games for Xmas.

 

If all this is too garbled, watch this nice Diagram of the evolution of the MJO through the phases which clearly demonstrates the kick the MJO wave delivers to the mean flow http://envam1.env.uea.ac.uk/images/wh04_mslp1.gif

 

More about Waves, MJO / Kelvin Waves in this great guide  http://www.kylemacritchie.com/equatorial-wave-background/equatorial-wave-theory/

Great post Tony, and just to add in addition to the tropospheric pattern that we want to see for local benefits from a meridional flow when the MJO reaches phases 6 onwards, we will also benefit with increased strat feedback through WAF from phase 6. So, tentatively, we should start watching out for an EAMT from day 10 onwards and perhaps early signs of surf zone upper stratospheric warming a few days after that.

[Gael_Force]

Yes, a good post from Lorenzo. I think a wider view from the Adrian Matthews website will help to allay some fears about Bartletts getting going. Look at the stream function for 200mb and you can see the influences of the current phase; that should only be temporary if the models are right.

 

 

http://envam1.env.uea.ac.uk/mjo.html

[Barry12]

Just noticed the -8 'uppers' are not far away at all on the UKMO day 6. Friday could be a day to look out for snow to lower levels. We should see soon if the -8 uppers that are touching Scotland will make it further south on the 12z.

 

 

There further away on the ECM though

 

Edited November 29, 2014 by Barry95

[Midlands Ice Age]

 

Just noticed the -8 'uppers' are not far away at all on the UKMO day 6. Friday could be a day to look out for snow to lower levels. We should see soon if the -8 uppers that are touching Scotland will make it further south on the 12z.

 

 

There further away on the ECM though

 

Barry,

Far be it for me to curb your enthusism, but it is the -6C just off Scotland.

The -8C is up by Iceland.

MIA 

[Barry12]

 

Barry,

Far be it for me to curb your enthusism, but it is the -6C just off Scotland.

The -8C is up by Iceland.

MIA 

 

Oh, that's embarrassing  

[AWD]

Barry,Far be it for me to curb your enthusism, but it is the -6C just off Scotland.The -8C is up by Iceland.MIA

Plus there are a hell of a lot more parameters to consider when trying to forecast snowfall than solely looking at 850hpa Temps. Edited November 29, 2014 by AWD

[Barry12]

Plus there is a hell of a lot more parameters to do consider when trying to forecast snowfall than solely looking at 850hpa Temps.

 

I know that's why I said 'could'.

[shaky]

Plus there are a hell of a lot more parameters to consider when trying to forecast snowfall than solely looking at 850hpa Temps.

which means we could have 850 temps of -2 and it could still snow!! Especially if flow slack/off the continent! !

[Paul]

For those who may be considering subscribing to Netweather Extra to get access to the extra data, NMM models, 5 minute radar etc for the winter, we currently have a winter sale on

 

More info here:

http://www.netweather.tv/secure/cgi-bin/premium.pl?sess=

[Cloud 10]

Is that a northerly on the 12z UKMO?

 

[Allseasons-Si]

Nobody commenting on the ukmo

 

nh view

 

so ukmo continues with it's northerly while gfs is still having none of it.

 

Edit:cloud10 pipped me.

 

also gem could be good too

 

@ 120hrs @150hrs

 

so both ukmo and gem at it again,i await the ecm.

Edited November 29, 2014 by Allseasons-si

[Gael_Force]

Nobody commenting on the ukmo

 

UW144-211.GIF nh viewUN144-2134.GIF

 

so ukmo continues with it's northerly while gfs is still having none of it.

 

Edit:cloud10 pipped me.

 

Nothing new in that - GFS first shows the idea in far FI then drops it just as the other models pick it up at the point of verification stats ie. seven days.

[shaky]

Semems to me as though the gfs has been increasing the amplification run by run around greenland! ! Gona be a slow one from the gfs i think!! Ukmo still gunning for the northerly! !

[Cloud 10]

The 12z GEM is considering the options at 120 hrs...