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Model Output Discussion; into 2015


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I think this is the first time we've seen this winter the GFS & the GFSP show a serious set up for serious cold over western Europe. a blocking ridge extending from the equator to the Pole across the Atlantic with a large low to the south east over Spain. In my view its similar to the run-ins to 2009 / 10 and 2010 / 11 where a period of northerlies bringing snow to the north coasts changed to a period of easterlies bringing the widespread cold and snow streamers. I've not seen this appear in any operational run this winter; if it has I'd love to to when?

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12z clusters are offering glimpses of a different story after mid-month with markedly more meridional pattern(s), but of course it's just not worth detailing all that stuff showing out post-15 Jan unt

Some very poor quality posts have been creeping into the discussion which really don't add anything to the thread apart from raising the ire of many who view this thread....Even a simpleton (in meteor

Nice tease from the ECM, no surprise looking at the strat charts, shame it can't happen though because apparently cold is not possible before Mid Jan!?!   Rule nothing out folks, as I posted yeste

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I think this is the first time we've seen this winter the GFS & the GFSP show a serious set up for serious cold over western Europe. a blocking ridge extending from the equator to the Pole across the Atlantic with a large low to the south east over Spain. In my view its similar to the run-ins to 2009 / 10 and 2010 / 11 where a period of northerlies bringing snow to the north coasts changed to a period of easterlies bringing the widespread cold and snow streamers. I've not seen this appear in any operational run this winter; if it has I'd love to to when?

I'm guessing around the 18th dec 2014. don't have the time to check if out but anyone with 5 mins can check the archive gfs/p fi's on meteociel. Maybe not in the same detail but there were some very wintry runs around that timescale.

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Plenty of support in the 06z GEFS ensembles for the operational run with its FI shenanigans,including this "vortex pays a visit" solution from number 11

 

attachicon.gifgensnh-11-1-360.png

Funnily enough that's ok at day 16 but if would evolve into a stormer! Uppers only -2/-4c under the trough. V Low heights would assist though.

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Just producing charts like that is very unscientific and really of no use.

Surely it's empirical evidence (to make the point about how patterns can change within 10 days) how can that be "unscientific"?

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Sorry JH. Just looked back and it was someone else who replied to Ian.

Yes, that was me!

I assumed by meridional that we would be primarily looking at a NW (or maybe NNW) flow, which in my experience is not really a snow giver for the South. However as Severe Siberian Icy Blast mentioned, it is possible to get snow for the South in these setups particularly if there is entrenched cold air already present or disturbances in the flow, but history has told me that it is much harder without some kind of Easterly element.

I guess it's because I have seen far too many N'lys deliver nothing to me except wind chill!

Although having seen your location Cornish Snow, you might not benefit from Easterly elements and might well do better with a NNW anyway! :)

Edited by Long haul to mild
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Surely it's empirical evidence (to make the point about how patterns can change within 10 days) how can that be "unscientific"?

 

Yes, but the problem is for every one that went to the change shown (easterly) there were hundreds that didn't (remained zonal). I could show many more that were poor later charts, and of course that would be just as useful. :sorry:

 

ECM next 10 days looks like above average for London as a whole: post-14819-0-22331200-1420288761_thumb.g

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Expect to see the GFS and ECM produce winter wonderland charts in FI on one run to only completely abandon them on the next run for several days. From one run to the next doesn't matter but the fact that's theres even a remote sign of an end to this zonal weather hell is better than where we were. Enjoy the eye candy while it lasts

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Expect to see the GFS and ECM produce winter wonderland charts in FI on one run to only completely abandon them on the next run for several days. From one run to the next doesn't matter but the fact that's theres even a remote sign of an end to this zonal weather hell is better than where we were. Enjoy the eye candy while it lasts

:drinks: STellas on ice ,ice pixs at the ready ,come on models its been a longgggg wait .

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It only turns colder though by day 11 onwards so how much can we trust this. Given the average for January is around 6/7C that means outside of this weekend temperatures will be at or above average. I suspect by mid-month we will be running at between 1 and 2C above average (strong winds will make frosts pretty fleeting beyond this weekend).

The main interest weather wise will be the potential for very strong winds, most notably around day 6 again on the parallel

gfs-0-144.png?6

Gales, perhaps severe for Scotland.

So there is still potential for the strong westerly jet to ease during the second half of week 2, but that is all at the moment. Like IDO, I feel rather sceptical about any potent Arctic blasts, and as we have seen we can't just assume the the positive drivers for this winter will be enough to get these cold charts over the line.

Today and Tomorrow ??

 

Point is mild muck isn't dominant

Edited by Banbury
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I know it's the mean anomaly and at T360 so take that as read but this mornings extended EPS was hinting along the same lines

Charts weatherbell

post-12275-0-04215600-1420290618_thumb.p

post-12275-0-10793500-1420290625_thumb.p

Edited by knocker
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The overview of the MJO by NOAA makes for interesting reading, this was the weekly update compiled on the 29th December, I'll be interested to see what their next update says.

The MJO remained active and strengthened during the past week. Other modes of variability are constructively interfering with the MJO.

• The upper-level fields are coherent with MJO activity, while the lower-level wind fields have some other factors influencing the pattern. The RMM and the CPC Velocity Potential Indices both indicate enhanced convection over the Maritime Continent.

• Dynamical model MJO index forecasts generally depict eastward propagation of an MJO signal by Week-2 to the West Pacific. Statistical models agree with the majority of the dynamical models.

• The MJO is forecast to remain active over the next two weeks, favoring enhanced convection shifting slowly from Maritime Continent the western Pacific.

You'll see they mention the western Pacific which starts getting towards phase 7, because of the lack of help from the strat so far I do think we're going to need some help from the MJO.

Edited by nick sussex
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Yes, but the problem is for every one that went to the change shown (easterly) there were hundreds that didn't (remained zonal). I could show many more that were poor later charts, and of course that would be just as useful. :sorry:

 

ECM next 10 days looks like above average for London as a whole: attachicon.gifensemble-tt6-london (7).gif

 

I'm not disagreeing with your assessment but why would you post ensembles such as ECM without remark on the most striking aspect?

(Sharp zonal signature slowly subsiding toward mid month with colder cluster thereafter)

 

You don't have to ramp but worthy of a cautious mention at least in any analysis, no?

Edited by Mucka
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I'm not disagreeing with your assessment but why would you post ensembles such as ECM without remark on the most striking aspect?

(Sharp zonal signature slowly subsiding toward mid month with colder cluster thereafter)

 

You don't have to ramp but worthy of a cautious mention at least in any analysis, no?

 

Hi

 

I don't have access to the ECM extended ensembles, clusters or otherwise. I would therefore be guessing at why the mean 2m temps slowly falls by a couple of degrees from D10-15 for London. That type of expert analysis I leave for IF, Knocker, BA and others, who have more info. However I assume the clustering shows that there is a fall off in a zonal flow within the latter part of those extended 5 days, that is if the GEFS are anything to go by. I was in fact referring to several posts that suggested the next 10 days had trended colder than average, when neither the GFS or ECM ops suggest's that.

 

GFS 06z London 2m temps: post-14819-0-51412900-1420297344_thumb.p

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Although we're seeing some better outputs today we should bear in mind that we're talking of changes starting to occur around the T240hrs timeframe.

 

At this point theres no way of determining whether this will involve a northerly toppler type scenario or cold spell.

 

The first step is to displace the Azores high and get the jet track more nw/se. We need to see this constantly modelled and survive to the T168hrs timeframe.

 

Looking at the ECM ensembles they do show a colder cluster developing from around day 11 but at this time don't show an Arctic sourced northerly more a colder type PM flow which of course is better than whats currently on offer but really after such a long wait what we want to see is something that delivers UK wide.

 

That may still happen and a trend to amplify the pattern might be given some further help if the MJO can actually survive and remain strong.

 

So today some cause for optimism but really no more than that and certainly nothing warranting a trip to the sledge shop.

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http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

just  had  a  look  in to fantasy  world  the  coldies  could be licking their lips after  jan  17  for some cold  weather!!!

yes but fantasy is the crucial word there.thats all it is nothing would please me more but until its falling from the sky I will leave it in fantasy world.
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Although we're seeing some better outputs today we should bear in mind that we're talking of changes starting to occur around the T240hrs timeframe.

 

At this point theres no way of determining whether this will involve a northerly toppler type scenario or cold spell.

 

The first step is to displace the Azores high and get the jet track more nw/se. We need to see this constantly modelled and survive to the T168hrs timeframe.

 

Looking at the ECM ensembles they do show a colder cluster developing from around day 11 but at this time don't show an Arctic sourced northerly more a colder type PM flow which of course is better than whats currently on offer but really after such a long wait what we want to see is something that delivers UK wide.

 

That may still happen and a trend to amplify the pattern might be given some further help if the MJO can actually survive and remain strong.

 

So today some cause for optimism but really no more than that and certainly nothing warranting a trip to the sledge shop.

 

I don't agree that the esembles show strictly a ''colder type PM flow'' in the latter stages, It could very well be a continental or north easterly flow.

 

Even in those juicy FI charts in a north easterly flow we only have uppers of around -5 to - 8 which coincide with what the esembles are showing:

 

Rtavn3722.gif

Rpgfs3602.gif

 

t850West~Yorkshire.png

.

 

 

So I think FI and the esembles really could be hinting at a more continental or NE flow type of spell on the horizon, this has my interest although very much muted at this early stage, one thing is for shaw though, the output is far better than it was 2 days ago : ).

Edited by Harsh Climate
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Although we're seeing some better outputs today we should bear in mind that we're talking of changes starting to occur around the T240hrs timeframe.

 

At this point theres no way of determining whether this will involve a northerly toppler type scenario or cold spell.

 

The first step is to displace the Azores high and get the jet track more nw/se. We need to see this constantly modelled and survive to the T168hrs timeframe.

 

Looking at the ECM ensembles they do show a colder cluster developing from around day 11 but at this time don't show an Arctic sourced northerly more a colder type PM flow which of course is better than whats currently on offer but really after such a long wait what we want to see is something that delivers UK wide.

 

That may still happen and a trend to amplify the pattern might be given some further help if the MJO can actually survive and remain strong.

 

So today some cause for optimism but really no more than that and certainly nothing warranting a trip to the sledge shop.

 

 

Indeed Nick hopefully signs of a significant change but simply eye candy and nothing more at present.

 

After many years of GFS let downs and Those ECM''s I'm sticking with my new Mantra this winter.

 

''You can scream and shout your happiness about ECM AND GFS

but it simply will not happen until the UKMET say yes.''

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