Model Output Discussion; into 2015

[mcweather]

The GFS model has certainly shown up some interesting wintry possibilities ( and that is all they are at the moment, possibilities) in FI over the last few days. It will be interesting if

 

a, It keeps displaying these possibilties

b,  Brings them inside the 240 range

 

c, if it manages to get to point b then will the ECM start displaying such possibilties?

 

Getting a half decent cold spell to the UK is always like pulling teeth. So I think its a case of coldies having to keep everything crossed.

[Polar Maritime]

Once again a very Wintry/Stormy run from the GFSP, With severe gale force winds snow/blizzards effecting the North with heavy rain at times spreading S/E over the UK. With a cool sometimes cold N/W Pm flow, It will feel bitter in the driving rain/sleet & snow.  A very traditional January affair, With plenty of Winter Storms to contend with.

 

Edited January 4, 2015 by Polar Maritime

[Winter Cold]

Its just another agonising waiting game for coldies isnt it, as usual. Both GFS's tonight for example arent great in FI. As far as I can see they are showing a very similar pattern to what happened on Boxing Day and the Atlantic high soon being pushed away over us

 

One set of runs though, and at those time frames its best just to enjoy the fact that they are still showing amplification. Trends

[terrier]

Not liking the gfs and ukmo tonight. Some very damaging winds on that output along with heavy rain. Very jan 2014 on those charts. Hopefully downgrades over the coming days. But with the cold flooding out of u.s I fear we are going to see a lot of damage if tonight's output verifys.

[Harsh Climate]

Not liking the gfs and ukmo tonight. Some very damaging winds on that output along with heavy rain. Very jan 2014 on those charts. Hopefully downgrades over the coming days. But with the cold flooding out of u.s I fear we are going to see a lot of damage if tonight's output verifys.

 

 

Wouldn't be complaining about this though would ya ; ) (in the unlikely event it verified.)

 

[Eugene]

Its just another agonising waiting game for coldies isnt it, as usual. Both GFS's tonight for example arent great in FI. As far as I can see they are showing a very similar pattern to what happened on Boxing Day and the Atlantic high soon being pushed away over us

 

One set of runs though, and at those time frames its best just to enjoy the fact that they are still showing amplification. Trends

 

 

GFS 12Z OP latter stages are very encouraging indeed with a russian high and a weakening atlantic, great potential for snowfall for snow starved southerners.

Edited January 4, 2015 by Eugene

[Mark Bayley]

I wouldn't have much faith in trend shown by the GFS (of mid-Atlantic ridging) until there is greater certainty on the MJO. The GFS was on its own (excluding 1 or 2 lesser models) in progressing through to phase 7; whereas the ECM has it dying a death in phase 6. Unfortunately the GFS charts are down. If the MJO struggles to make much progression, as the case has been through this winter, then something akin to the end December seems more likely. Sadly i see little support for any sustained cold, short or long term  

 

[TEITS]

I read a post this morning saying there was no sign of a change in the 10-15 day period based on the anomalies. My reply to this would be you need to look at all the available data because in my opinion that isn't the case.

 

The trend towards a change occurring from mid Jan appeared many days ago and since then has continued. Whilst the GFS Ops have obviously swung between just a brief colder spell to a more prolonged cold spell, the pattern change is apparent in the GEFS ensembles.

 

The Aberdeen ensembles show the alternating airmasses between low pressure systems but from mid Jan this becomes more sustained at -5C.

 

http://max.nwstatic.co.uk/ensimages/ens.20150104/06/t850Aberdeenshire.png

 

The best example of this coming pattern change is the Iceland SLP mean.

 

http://max.nwstatic.co.uk/ensimages/ens.20150104/06/prmslReyjavic.png

 

This is increasing all the while. The GFS Ops & GEFS control were a few days ago much higher than the mean but slowly other GEFS members are coming on board hence why the mean is increasing.

 

So my summary remains the same as the 29th Dec. From mid Jan a colder spell will develop via N/NE,lys. However how prolonged and cold remains uncertain. Initially the N/NE,ly will be via HP to the W of the UK. However this could develop into more sustained blocking to the N/NW/NE of the UK bringing a prolonged cold spell. On the other hand this blocking does not develop and after a few days of cold N,lys the block to our W is eventually toppled with a return to milder W,lys. At this stage my instincts favour the sustained blocking scenario and a prolonged cold spell!

[Winter Cold]

GFS 12Z OP latter stages are very encouraging indeed with a russian high and a weakening atlantic, great potential for snowfall for snow starved southerners.

 

Well if the 'bigger picture' is looking good then thats a bonus. We need all the help we can get i think!

 

My comment was really just looking at what the high does to our west, i hadnt looked at the NH view. Its a case of watching the MJO I think with regards to our high. When does FI end for the MJO? Are those plots any more accurate than other parts of models? For example, the strat forecasts are deemed to be more accurate for longer into FI than trop. When can we start to firm up on the signal to 7 or not?

[Barry12]

GEFS perturbation 3 is the best...

 

[SE Blizzards]

GEFS perturbation 3 is the best...

 

 

It's good, but it's not quite Carling! (unlike the latest CFS run below that has us locked in the freezer from mid February until April!?

 

A re-run of 2013 Anyone?

 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=1044&mode=0&carte=1&run=3

 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=1044&mode=2&carte=1&run=3

 

All just for fun of course     

Edited January 4, 2015 by SE Blizzards

[Frosty.]

Am I missing something here,  1-3c at 6 am in the morning in the middle of Jan, is hardly dream material is

LOL yes you were missing something, it was more about the very wintry synoptics developing with Greenland height rises, a blocked Atlantic, a large scandi trough and our weather coming from between north and east for many days.

[mushymanrob]

I read a post this morning saying there was no sign of a change in the 10-15 day period based on the anomalies. My reply to this would be you need to look at all the available data because in my opinion that isn't the case.

 

 

But dave, the current expected fi cold snap is just outside the 10-15 day mean... So currently theres no discrepancy between the (pretty reliable) anomaly charts and the other data. If theres going to be this mid atlantic ridge, it will show on the noaa 500mb charts before long.

[johnholmes]

I read a post this morning saying there was no sign of a change in the 10-15 day period based on the anomalies. My reply to this would be you need to look at all the available data because in my opinion that isn't the case.

 

Probably me Dave. I NEVER post based on one output or from one model although I do use the anomalies to give my views. Prior to posting I look each time at the synoptic outputs from all 3 models although UK Met only goes to 144h, I look at the ensembles, AO, NAO, MJO and make up my mind from all the data how to word my posts based on the anomaly charts. I hardly ever attempt to suggest what may happen beyond 15-17 days ahead, leaving that to posters more attuned to those teleconnections than I am.

 

You could be correct, although looking at the overall data  I am not yet convinced, the one for Iceland certainly shows enough in height rises on the particular one you show, on the trend assuming it is showing this consistently each day over the past couple of days at least?

 

Looking at the consistency for either the GFS 12 or 00z issues and for the same time/date ahead and that consistency is not there, nor is it on the ECMWF.

 

The current predicted pattern of the upper air is for much as now, some less cold slots, chiefly ahead of deepening surface features set up by the very strong upper flow which, as it often does, develops relatively minor kinks (troughs) in that upper flow. These in turn encourage surface features to form along with the temperature contrasts either side of the jet. Depending on the entry and exit of the surface feature with the jet stream how much they deepen and where. I don’t see any of these creating anything more than a temporary outbreak of cold and fairly deep polar air, 24-72 hours at the most.

 

What I do see on the anomaly charts is the very slight veering, consistently shown, on the NOAA 6-10 of the overall Atlantic flow to about 290 degrees as opposed to 260-270. This MIGHT be enough to make the polar incursions a bit more frequent but I have to honestly say that to me there is no consistent signal for deep and longer lasting cold showing yet. I will be in here once/if that shows with a comment about it.

 

Finally looking at the GFS outputs, both versions, and both show an indication of a deeper and colder evolution from about 240 hours. The trouble with believing their evolutions is they are not consistent over the past 3 days with this.

 

Anyway it is interesting model watching and we each have our own way for this. Looking closer in time and the probability of deep lows close to or even over northern Scotland remains. UK Met Fax chart 120h last evening shows one of 975mb in mid Atlantic so the path that takes may have a serious wind impact on some areas, possibly more to follow looking at the upper air pattern.

Edited January 4, 2015 by johnholmes

[TEITS]

But dave, the current expected fi cold snap is just outside the 10-15 day mean... So currently theres no discrepancy between the (pretty reliable) anomaly charts and the other data. If theres going to be this mid atlantic ridge, it will show on the noaa 500mb charts before long.

15th Jan is around the period of change which is 11 days away.

 

This date has consistently been suggested by the GFS/GEFS.

[mushymanrob]

15th Jan is around the period of change which is 11 days away.

This date has consistently been suggested by the GFS/GEFS.

Its not currently looking good for this change then!

Ill believe it when the anoms show it or/and when it reaches a semi reliable timeframe. The first lesson i learned when joining here ten years ago is dont believe fi... Watch it, but dont have high expectations as it more often then not leads to disappoint

Edited January 4, 2015 by mushymanrob

[TEITS]

Ill believe it when the anoms show it or/and when it reaches a semi reliable timeframe. The first lesson i learned when joining here ten years ago is dont believe fi... Watch it, but dont have high expectations as it more often then not leads to disappoint

Except when mild SW,lys are showing.

 

Only kidding mate.

[bluearmy]

Something strange on the gefs mean is the week 2 migration of the Aleutian vortex along the length of Asia to a favoured spot this winter of nw Siberia. It's not so much a migration as a mean stretching of the vortex along almost the whole of Russia. of course it won't end up like that as its a mean but it's a direction of travel for the low heights we are yet to see this winter.

there are evolutions out there through week 2 which would see this as part of the jigsaw to icebound nirvana for Europe. We won't go there for the time being as it's currently too diffuse on the perturbs and probably just a coincidence of the varying patterns at play.

[Frosty.]

Tonight's ECM 12z op run shows milder and colder airmasses trading blows but IMO the cold air, although not delivering a knockout blow, wins on points tonight with frequent polar maritime incursions, especially further north. It's a very unsettled outlook with occasionally very strong winds and heavy rain but cold enough at times for wintry showers and frosty nights, the south has the best of any fine weather between depressions.

[Eugene]

Tonight's ECM 12z op run shows milder and colder airmasses trading blows but IMO the cold air, although not delivering a knockout blow, wins on points tonight with frequent polar maritime incursions, especially further north. It's a very unsettled outlook with occasionally very strong winds and heavy rain but cold enough at times for wintry showers and frosty nights, the south has the best of any fine weather between depressions.

 

 

Yeah looks like we are going to escape the worst excesses of an atlantic pattern, azores high shifts around  from side to side to our south helping to pull in various airmasses but we avoid the toasty deeply sourced airmasses apart from later on friday/early saturday which is very transient.

[mushymanrob]

Except when mild SW,lys are showing.

 

Only kidding mate.

Lol.... Maybe, but mild southwesterlies are more likely to verify, no probs dave..

[IDO]

News from IF re latest UK Met: 

 

  fergieweather
New @metoffice data indicates no major Sudden Stratospheric Warming (SSW) is likely to occur "in the forseeable future". Moreover (cont'd)
04/01/2015 19:51

 

  fergieweather
Cont'd... they note their monthly and seasonal modelling from back on Dec 27 dismissed the prospect. They add that a... (cont'd)
04/01/2015 19:53

 

  fergieweather
Cont'd (3)...minor warming will be of minor significance, & resurgence of Polar Vortex/Polar Night Jet through nxt 2 weeks to 'near-normal'
04/01/2015 19:57

 

  fergieweather
(4) Finally, they add "The model ouput of other reputable forecasting organisations is also in agreement with the Met Office model trends."
04/01/2015 19:59

 

  fergieweather
(5) The @metoffice view re stratospheric situation was valid as of 1400hrs today. Clearly, the rest of winter cannot be forecast in detail.
04/01/2015 20:03

 

 

I suppose that puts that to bed for this month.

Edited January 4, 2015 by i'm dreaming of...

[Frosty.]

Lol.... Maybe, but mild southwesterlies are more likely to verify, no probs dave..

Not much of that on tonight's ecm run mushy.

:-)

[Timmytour]

Not much hope of something cold being given to us by the models or from an SSW then.

I might start buying the daily express as a source of hope to cling onto! :-)

[ANYWEATHER]

The "Seesaw" temperatures continue to be modelled by the gfs and ecm in the days ahead with some very volatile weather in picticular during later this week especially for Northern Britain. Any real eyefest for cold is at the moment in FI, but the middle of January at the moment looks pivitol for a colder change in synoptics