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Model Output Discussion 19th January 2014-18z onwards.


phil nw.

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Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

Whilst most eyes understandably remain focused on 'wintry potential' there's no escaping the fact GFS is wanting another significant storm later in the weekend. Showing up on the 06 as sub 945mb, which is probably a bit to low given the GFS's perpensity to over deepen things, but I suspect the MO's attention will be rather more drawn towards this over up coming runs rather than snow and ice.

 

Posted Image

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Posted
  • Location: HILL OF TARA IRELAND
  • Weather Preferences: SNOW ICE
  • Location: HILL OF TARA IRELAND

Well the end of the 06zGFS the cold uppers are coming from the east and west!It would be amazing if the British Isles were to miss out on a snowy spell at the end of the month good run!

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Posted
  • Location: Cardiff, Wales
  • Weather Preferences: Snow, Thunder & Lightning, Thundersnow, Storms, Heatwave
  • Location: Cardiff, Wales

Wish NCEP would just scrap the GFS low-res!! Pretty good agreement start of next week in terms of a deep low moving SE. Another cold ECM run but we must still be wary of the energy to the NW, will it turn out to be too powerful again. Think it has already been said this morning but a breakdown of the ridge in the pacific may actually help us in this respect. Ps. Nice to see you back to normal service frosty

Edited by bradythemole
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Posted
  • Location: Broxbourne, Herts
  • Weather Preferences: Snow snow and snow
  • Location: Broxbourne, Herts

The advance and retreat of the cold uppers....i believe in the advance, but i don't think the retreat will happen as shown....

The advance 

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....once those uppers get a sniff of the UK, they are not going to be in this hurry to leave....

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Posted
  • Location: Dorset
  • Weather Preferences: warehamwx.co.uk
  • Location: Dorset

with much more interest as we head into the weekend and next week for snow.

Just a vague look at the models for the weekend doesn't look that interesting if you're a coldie, a hint of some transient snow over high ground, perhaps 200m+ later in the week but a return to milder conditions during the weekend. The GFS and ECM possibly bring some colder air in behind an area of low pressure next week, so perhaps frequent showers with a wintry theme could be on the cards but haven't we seen that before? Back in December?I admire the optimism though. :) Edited by Mapantz
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Posted
  • Location: st albans
  • Location: st albans

i wasnt overly impressed with the ecm suite today and the london ens confirm that. they are not as cold as yesterdays 12z run. awaiting the 12z with interest but given the 00z run, i wouldnt be expecting too many 'fireworks' from exeter's update.

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Posted
  • Location: Manhattan, USA
  • Location: Manhattan, USA

Forget FI - We have a potential snow event on Thursday (2 DAYS AWAY!!!)

 

Mainly for the North & Higher ground, but might surprise a few...

 

Latest FAX shows the two occluded fronts, and the 528DAM...

 

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Posted
  • Location: Exeter, Devon
  • Weather Preferences: Snow, thunderstorms
  • Location: Exeter, Devon

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=307&y=139 (South East England)

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=188&y=176 (South West England)

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=265&y=1 (Northern England)

 

Another very good set of ENS. There are some good trends developing in the output at the moment, both in the troposphere and in the stratosphere! Let's see if we can get the trends in place properly and then that's where the specifics start to become relevant. Already we've observed how tiny corrections westwards and eastwards can drastically alter the sort of weather we will see. That's what we get for living on an island next to a vast landmass and a vast ocean!

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Posted
  • Location: South Gloucestershire BS35
  • Weather Preferences: Severe weather enthusiast
  • Location: South Gloucestershire BS35

What is interesting is how far the cold 850 uppers are making it across the Atlantic from the W/NW without getting mixed out a great deal as they approach the UK. This has been showing up on multiple runs these past few days.

 

Realisticly, I would assume more mixing out as the time gets closer to the realiable timeframe (if it was to verify as shown of course)...however it would tie in with Ian F's comments mentioning the unusual temperatures showing up from a westerly flow.

 

...and yet we have UKMO just now describing early next week as "stormy"; noting how any low as per ENS in N Sea could yield "considerable disruption" to coastal fringes; plus how even EC's westerly flow looks "unusually cold for the direction... bringing higher risk of ice/snow than would be normal (from that direction) in late Jan/early Feb.. "None of which shouts 'average' in my book....

 

Now I am not saying the above is a certainty - I do think we are in for a rather nail biting time when it comes to model watching (Durrr..). And that is of course if you have any of your nails left already...

 

I wonder if we could be looking at a rather unsettled spell coming but with a bit of a cold twist...question being though...a cold enough twist?  

Edited by Chris K
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Posted
  • Location: Longwell Green, near Bristol
  • Weather Preferences: Storms, Gales, frost, fog & snow
  • Location: Longwell Green, near Bristol

Forget FI - We have a potential snow event on Thursday (2 DAYS AWAY!!!)

Mainly for the North & Higher ground, but might surprise a few...

Latest FAX shows the two occluded fronts, and the 528DAM...

Posted Image

Looks primarily for areas around 500m+

post-12721-0-60002200-1390306243_thumb.j

Perhaps slightly lower down in Northern Ireland where some modest 850hpa temps and thickness values are felt from the northern Atlantic;

post-12721-0-22789700-1390306330_thumb.j

post-12721-0-60157900-1390306505_thumb.j

Edited by AWD
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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

The met office are picking up on the potential for some wintry showers on Thursday now

 

Further showers, perhaps wintry, merging into longer spells of rain Thursday

 

It certainly has potential it has to be said

 

Posted ImagePosted ImagePosted Image

 

 

Longer term (Sunday 26 Jan 2014 to Tuesday 4 Feb 2014) its as you were though this time more unsettled in the north and west with hill snow at times interspersed with clearer, colder, more showery conditions, and brisk winds with the best of the drier and brighter weather in the south and SE. A continuing risk of local overnight frost and fog. Rather more settled weather is possible in the far south by the end of the period.

Edited by Summer Sun
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Posted
  • Location: Manhattan, USA
  • Location: Manhattan, USA

Looks primarily for areas around 500m+

Posted Imageimage.jpg

Perhaps slightly lower down in Northern Ireland where some modest 850hpa temps and thickness values are felt from the northern Atlantic;

Posted Imageimage.jpg

Posted Imageimage.jpg

 

Not really, you can't choose 6AM charts when the Front isn't even here. Looking at the actual time it's crossing:

 

Posted Image

 

100M.

 

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Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

Incidentally, CFSv2 has been rather consistent with its advertising of colder solutions through mid-February and extending into March.  This pseudo trend isn't too dissimilar to how it equally advertised colder synoptics in February 2013, albeit a fair bit more moderate.  The broad synoptical picture is an omnipresent high pressure cell centred over Scandinavia; consistent in synoptical flavour with stratospheric downwelling propagating through to the troposphere.

 

Whilst GS5 isn't wholly reflective of that which CFSv2 proposes, that isn't to say that its broad synoptical proposal should be dismissed out-of-hand.  Variance is high and that isn't unexpected; at mid-range it's not so much about detail as such, but more broader patterning.  If consistency can be identified in that context, then confidence can be raised, and detail ascribed once within range of more conventional NWP modelling suites.

 

Boom Boom Boom, let me hear you say way-oh, way-ooh! Posted Image

 

It does appear that the MO are for now at least focussing on an unsettled theme, with the big Sunday/Monday LP already in their thoughts...and probably plans. No indication that any undercutting of the block is currently expected, but I suppose given the complexities of the pattern going forward a short term seachange of emphasis is not wholly out of the question.

 

UK Outlook for Sunday 26 Jan 2014 to Tuesday 4 Feb 2014:

Turning very wet and windy on Sunday, with the heaviest rain and gales, locally severe, in the northwest. Rain should clear to sunshine and squally showers on Monday, with the best of the brightness in southeastern Britain. Mild at first in the south but turning colder. Thereafter the unsettled theme is likely to continue, especially in the north and west of the UK. Bands of rain are likely, with hill snow at times, interspersed with clearer, colder, more showery conditions, and brisk winds.

Edited by shedhead
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Posted
  • Location: Longwell Green, near Bristol
  • Weather Preferences: Storms, Gales, frost, fog & snow
  • Location: Longwell Green, near Bristol

Not really, you can't choose 6AM charts when the Front isn't even here. Looking at the actual time it's crossing:

 

Posted Image

 

100M.

 

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I prefer to use high-res modelling where possible rather than GFS Operational charts and the high res stuff only goes out to 48hrs currently, hence why I didn't go no further than 06:00.

You're right in that the GFS Op is a little more bullish in bringing some wintriness more widely across the UK, but it's not something I would put much confidence in re snowfall personally.

Let's hope future high res output upgrade the potential though. :)

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Posted
  • Location: Manhattan, USA
  • Location: Manhattan, USA

I prefer to use high-res modelling where possible rather than GFS Operational charts and the high res stuff only goes out to 48hrs currently, hence why I didn't go no further than 06:00.

You're right in that the GFS Op is a little more bullish in bringing some wintriness more widely across the UK, but it's not something I would put much confidence in re snowfall personally.

Let's hope future high res output upgrade the potential though. Posted Image

 

Yes agree re High-Res - but even Metoffice going for Wintry showers on Thursday now too.

 

Fingers crossed.

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Posted
  • Location: Exeter, Devon
  • Weather Preferences: Snow, thunderstorms
  • Location: Exeter, Devon

I think that the continued programme of see-sawing of ensemble suites is totally predictable based on what seems to be a never ending escalation of uncertainties that started with the easterly teases.

 

With an arctic high modelled in a close time period, a further ejection of disrupting vorticity aimed at us downstream from the Canadian blob, an ever lurking Russian High and attendant cold pool to the NE, uncertainties over a tropical forcing signal that is just one part of unknown amplification potential to add much needed spark to a sulky atlantic pattern; and last but not least how two further programmed stratosphere warmings straddling the end period of Jan/early Feb further add uncertainty to the modelling of the polar field and how they may effect energy transport and (hopefully) demise of the vortex blob from hell...then one thing that is very certain is to assume further upgraded chaos of the highest order for the NWP in the foreseeable future!Posted Image

 

So,um exactly, Exeter aren't going to even blink against the background of that little lotPosted Image

 

However, as suggested last night, its all there for the taking even though it requires a synergy of timing allied to some forcing and atmosphere payback for this soggy wind and rain battered island.

 

Donations please therefore to coldinuk@northernhemisphere.com

I know it's become my automatic comment for everything this winter, but I definitely agree about the stratospheric warmings. The vortex has been very slowly weakening for weeks now, thanks to a series of smaller warmings. The GFS has not let go of the signal for a warming on the 31st Jan/1st Feb onwards for several days now, hence charts like this.

Posted Image

Edited by Joe Levy
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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Thanks weather boy, I have mentioned recently about the wheel of fortune which has been strongly against cold weather so far this winter but is now spinning towards a wintry outlook, about time too!Posted Image Posted Image Posted Image

Edited by Frosty.
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Posted
  • Location: portsmouth uk
  • Weather Preferences: extremes
  • Location: portsmouth uk

well new sunspot 1963 must be a good omen lol.

anyway back to the models looking at the fax t120 I cant see why the low to our nw cant spill se the blocking to our northeast is so finely poised to pounce,

and its clear to see the uncertain nature of moving beyond t120 a plunge south east under cut not out of the question just yet.

the jma has its self shown how this can happen.

 

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Posted
  • Location: North East London (E4) 147ft
  • Location: North East London (E4) 147ft

Wish NCEP would just scrap the GFS low-res!! Pretty good agreement start of next week in terms of a deep low moving SE. Another cold ECM run but we must still be wary of the energy to the NW, will it turn out to be too powerful again. Think it has already been said this morning but a breakdown of the ridge in the pacific may actually help us in this respect. Ps. Nice to see you back to normal service frosty

Agreed. The key problem with the low-res is that you can write it yourself 99% of the time: It always just shows the Atlantic barrelling through regardless of the sypnotics. Of course, that's not a bad shout in the UK much of the time (hence why it is so programmed) but can make the GFS look damned stupid in blocked situations a la Dec 2010. As such long range forecasting is effectively impossible, why make yourself a hostage to fortune by actively designing a predictive programme that has almost zero chance of verifying? Note to the US Govt – bin it!

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