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Model Output Discussion - 31/10/2014 and Beyond


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The phrase I would most associate with the output is "stuck in a rut" - we don't seem to be going anywhere right now. I'm not too pessimistic because I think the models have a lot to resolve in the mid term and I don't think this is a done deal either way. I'd rather this than a direct signal for a flattening of the jet stream.

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The GEM goes down the ECM route of trying to build heights in towards the UK into week 2. Whether it will succeed to dry things out or not is another question, but it is plausible given the cold air will dig south into the western Atlantic which may allow a reprieve for western Europe which has taken quite a wet hit.

gem-0-168.png?12

The GFS and parallel keep us too close to the trough and continue our affair with wet and fairly mild conditions with a flow from the south. The UKMO doesn't look like following the GEM to be honest. The key seems to be the Atlantic ridge that gets squeeze as the GEM and ECM use this to retrograde the Eastern European block enough to build heights just to our north.

Edited by Captain shortwave
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Looking through GFS ensembles out into FI two things stand out.

The first is the lack of a cold signal and the second the lack of a typical zonal signal. There is no sign of the PV taking over and driving Westerlies across the UK at the moment but rather variations of MLB and HLB.

 

I know a few fancy there to be a transition into a strong zonal set up toward end of Nov and through first half of Dec or thereabouts before blocking returns with a vengeance.

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Stongingly mild air approaching us from the south at the end of the reliable tieframe on the12z GFS

Rtavn1922.gif

Low teens to start

Rtavn19217.gif

Then warmer

Rtavn2162.gif

Rtavn21617.gif

Meantime towards the end of the run cold air into Scandinavia

Rtavn3842.gif

But will never reach us :laugh:

 

GFS Parallel stays toasty right to the end

Rpgfs2102.gif

Rpgfs2372.gif

 

 

Is it going to be one of those winters where all of N America and Europe are plunged into the freezer and the UK remains just out of range of the cold and stays damp and mild? I wouldn't bet against it! :doh:

 

No disrespect but charts 9 days away aren't to be taken seriously , hopefully you aren't

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Stongingly mild air approaching us from the south at the end of the reliable tieframe on the12z GFS

Rtavn1922.gif

Low teens to start

Rtavn19217.gif

Then warmer

Rtavn2162.gif

Rtavn21617.gif

Meantime towards the end of the run cold air into Scandinavia

Rtavn3842.gif

But will never reach us :laugh:

 

GFS Parallel stays toasty right to the end

Rpgfs2102.gif

Rpgfs2372.gif

 

 

Is it going to be one of those winters where all of N America and Europe are plunged into the freezer and the UK remains just out of range of the cold and stays damp and mild? I wouldn't bet against it! :doh:

 

Hi yes could be, the forecasters in America are now getting excited about a repeat of last winter for them ! 

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Comparison between the big three at day 5

 

ECH1-120.GIF?11-0gfsnh-0-120.png?12UN120-21.GIF?11-18

 

The PV lobe to the east looks more broken up on the ECM, should be a good thing, I think!

Edited by Barry95
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It's at day 5 on the UKMO:

 

UN120-21.GIF?11-17

 

The shortwave just of the southern tip of greenland.

 

post-1235-0-61824700-1415646725.jpg

 

The ECM is the chart Steve Murr posted last night, highlighting the shortwave.

Might be wrong, but I'm not sure that's meant to be an actual Shortwave to be honest. Looks more like a little closed off Low with that circular centre (at least according to a post I've read from somewhere else).

Looking at the models, they seem to be carrying on with a theme of areas of low heights to the West slipping South-Eastwards against the blocking to our North East - an Easterly possible around the late-weekend, onwards. Some uncertainties as to how long it could last, but may just be brief. And although the Easterly doesn't fetch in cold 850 hPa temperatures (I suppose it is a bit too early, though, plus it could do being more Arctic sourced), could still feel very cool in places. Then the possibility that the blocking High Pressure to the North East could make a move over us, stay to our North-East, or perhaps become a blocking High to our East with Low Pressure systems getting held up to our West. Certainly by no means a done deal, though, But I must admit I'm getting more and more doubtful about a cold and snowy spell developing within the next 10 days or so... although then again, a snowy spell didn't really seem that likely in the first place. Late-November/December and beyond, could certainly offer better chances, however.

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thanks Barry for the explanation

Just a personal thing with me but the term is bandied around far more than the definition warrants in my view but that is probably just me.

http://weatherfaqs.org.uk/node/144#Shortwave

Is a good explanation of the term.

Great explanation and a really good read, combined with your anomaly explanation (about 2 weeks ago) once I fully understand I would like to join the thread ...until then thanks 

Russell

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No disrespect but charts 9 days away aren't to be taken seriously , hopefully you aren't

 

except when they show cold?

:)

 

sometimes surface charts look pretty impressive for cold

 

post-2797-0-04480400-1415730457_thumb.gi

 

a typical chart that in winter could deliver snow.

 

but view the 'uppers', the 850hpa temperature profiles

 

post-2797-0-55349800-1415730591_thumb.gi

and youll see that its not a cold outlook, but an average-mild one which id suspect would be pretty murky and grey.

 

several days ago now the gfs suggested the greenland/northern high would slowly sink southeastwards. the ecm 00z and several successive gfs runs are now broadly agreeing that this is the most likely solution. this progression can be viewed here (for novices/newbies)

http://www.wetterzentrale.de/topkarten/fsecmeur.html.

 

whilst several previous ecm runs were championing something cold from the east, or north, the gfs didnt. some gfs runs suggested the milder option that is now the current favorite evolution. hence why i wouldnt recommend ignoring the gfs. statistically its not as accurate as the ecm, but sometimes gets it right and / or isnt that far behind the ecm performance wise.

HOWEVER, nothing that far ahead is yet resolved. there is time for changes , there is alot of cold air to our north. it is possible yet that one of the solutions put foreward for cold might yet happen.

 

but

 

its not looking likely currently.

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According to ECM 12z, the Northern Hemisphere profile at t+168 has to be seen as encouraging. Preceding my first chart at t+168 (18th November) (the all important weekend timescale) will have already seen two days of Easterlies. Next question is just where does Atlantic High Pressure want to position itself. Ideally we could do with some WAA being pushed into the Greenland area by the end of the run but will it produce the goods and more appropriately, how does this scenario tally with the other NWP outputs at such a timescale?

 

 

post-7183-0-90948200-1415731550_thumb.gi

 

 

By t+192 (19th November) we will have already witnessed three days of Easterly flow as shown below.

 

post-7183-0-85622600-1415731726_thumb.gi

 

Whilst I don't intend to get carried away with this particular aspect it certainly helps in the overall European situation moving further into FI.

 

In all, it's still very much a complex global pattern but to me, it's a very promising NH profile with the usual cold weather indicators in place. I am especially enjoying the trend of the arm of the NH Jetstream staying way South during the next ten days or so, yes it meanders about a bit but you get the idea. Will be handy for us coldies should this continues to be the trend moving into later November. No ramping UP of it just yet, that's for sure. 

Edited by gottolovethisweather
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^^^ Yes the ECM op this morning was a synoptic outlier compared to its mean:

 

D10 post-14819-0-23792900-1415731667_thumb.g  Mean: post-14819-0-25135500-1415731677_thumb.g

 

The mean was much closer to the GEFS mean. ECM D8-10 are carrying on from last Winter and this Summer with over doing heights so any op should be ignored till it is backed up by the GFS. However it will be followed by cold lovers as it will continually throw up more seasonal FI charts. GEM is another culprit, even worse than ECM. Not saying that ECM is wrong, but caution is best advised when looking at latter ECM charts.

 

D9 on the 12z from ECMpost-14819-0-56864300-1415731902_thumb.g

 

Lets see later if it has dragged any of its ensembles towards that pattern...

Edited by i'm dreaming of...
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except when they show cold?

:)

 

sometimes surface charts look pretty impressive for cold

 

attachicon.gifRpgfs1621.gif

 

a typical chart that in winter could deliver snow.

 

but view the 'uppers', the 850hpa temperature profiles

 

attachicon.gifRpgfs1622.gif

and youll see that its not a cold outlook, but an average-mild one which id suspect would be pretty murky and grey.

 

several days ago now the gfs suggested the greenland/northern high would slowly sink southeastwards. the ecm 00z and several successive gfs runs are now broadly agreeing that this is the most likely solution. this progression can be viewed here (for novices/newbies)

http://www.wetterzentrale.de/topkarten/fsecmeur.html.

 

whilst several previous ecm runs were championing something cold from the east, or north, the gfs didnt. some gfs runs suggested the milder option that is now the current favorite evolution. hence why i wouldnt recommend ignoring the gfs. statistically its not as accurate as the ecm, but sometimes gets it right and / or isnt that far behind the ecm performance wise.

HOWEVER, nothing that far ahead is yet resolved. there is time for changes , there is alot of cold air to our north. it is possible yet that one of the solutions put foreward for cold might yet happen.

 

but

 

its not looking likely currently.

Not from me , read my signature, FI starts mostly between D5 and D10, can't hide from that fact

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Not from me , read my signature, FI starts mostly between D5 and D10, can't hide from that fact

 

fair play :)

Day 6 is not FI at all in my opinion...

 

fi varies depending upon the reliability and certainty of the output.

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Not from me , read my signature, FI starts mostly between D5 and D10, can't hide from that fact

So your signature says (FI is JFF)... Just for fun! But most on here love to see whats in FI, maybe just to see what it may bring us,

Me well! 'JFTHOI' love to see what's in FI 'just for the hell of it' :yahoo:

 

gfs-0-384_lhk2.pnggfs-1-384_xod1.png

Edited by Dancerwithwings
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Please let the ECM op be on to something here. I wish this for three reasons. Firstly, many of the classic cold spells are preceded by a period of blocked, anticyclonic weather. Secondly, the blocked scenario that the ECM is showing allows the cold to build and build to our east and north east. And last but not least, it goes against the Meto extended forecast for the next 2 to 3 weeks. If the met have got the signal wrong for the next couple of weeks then how can their winter thoughts be on the money? :)

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The best thing about the ECM if it verifies is that yet another Daily Express ridiculous weather story implodes!

 

I think a spell of quietish weather would be welcome for many and the flow would become progressively colder,  ordinarily we might be waiting for the high to sink as the PV took on a menacing tone to the north but theres always a chance that we might see eventual retrogression of the high as the PV is still split and reluctant to set up in its normal winter location.

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Personally i like the ecm12z that might have dropped the idea of the high slowly sinking southeastwards but it leaves us in a cool easterly which would dry things up somewhat.

But currently theres not much support from other data sources. Yet.

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Well the Euro does back it's morning run is raising heights close to the UK but it's still likely an outlier compared to its ensembles and more progressive peers. 

 

Certainly a possibility though and offers some scope for inversions (albeit the easterly element with relatively warm uppers would probably produce statocumulus murk).

 

Recm1921.gif

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Day 6 is not FI at all in my opinion...

Hmmm , I have watched the Sunday forecast in the past and sat waiting for Snow to fall on the following Friday and seen absolutely nothing, but it is all about opinions as you say.

 

Mushyman has a valid point

Edited by Banbury
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So your signature says (FI is JFF)... Just for fun! But most on here love to see whats in FI, maybe just to see what it may bring us,

Me well! 'JFTHOI' love to see what's in FI 'just for the hell on it' :yahoo:

 

gfs-0-384_lhk2.pnggfs-1-384_xod1.png

Correct, hence it is Just For Fun, very rarely does a 216 come to fruition :rolleyes:

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Ecm and gfs at T+192 . Ecm is keen to bring a pressure rise from the Northeast ,gfs not. Plenty of cold air to tap into ,but be patient, the blocking is still there  Still early days for real cold. for the Uk, look at November/ December 2010, perfect winter synoptics so early on, but it peaked to early with the main winter months of January and February devoid of anything remotely wintry. :nonono:  :rofl:  :closedeyes:

post-6830-0-57195800-1415734831_thumb.pn

post-6830-0-72155000-1415734894_thumb.pn

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