Model Discussion January 18th

[TEITS]

GEFS control has gone made and brings in an E,ly at +204.

LP moves SE!

I sense this LP is going to drive us mad over the next few days.

[OldMetMan]

Despite the odd GFS run suggesting HP to the east over recent days, it looks to me as if there is a better consensus between the main 3 models for keeping things moving across the Atlantic. Even the ECM looks a little less deranged than it did a couple of days ago and is broadly similar to the UKMet and GFS.

There just seems to be no end to the constant succession of LPs coming out of Canada/the US. There were signs the other day of a slowing down of the US jet but, in spite of there being more meridionality over the E Pacific in the last few days, the NW jet into the Pacific Northwest seems to be pepping up again and the sub-tropical jet is still racing NE across the southern US states, so the 2 combined seem to be generating these endless LPs.

The only point in all the runs where there may be some chance for a slow down is between about 96Z and 120Z where the Atlantic flow slackens off, whilst a rapidly developing LP south of Greenland gets its act together, but the main models at present are pushing its frontal zone well ahead of its centre towards us and keeping the mobility going. If this LP, should it verify,deepen enough to slow right down and turn N, then it might allow some room for HP to build westwards across the Norwegian Sea towards Iceland as the end of train LP near the UK heads away to the E, letting some cold NE winds come at us. But I think that is a big "if".

All in all, there seems little prospect of any cold E flow just yet, although the 528dm thickness moving N and S across us in the next few days will most likely allow for some wintry activity, mostly in the N I would think.

We'll see how the models handle the 4-5 day timeframe in the next couple of days - the output could conceivably change quite a lot.

[LomondSnowstorm]

Very interesting control run - that much vaunted 'negatively tilted troughing' shows uphttp://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-138.png?18

and the trough then slides southeastwards into Europe http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-192.png?18

[BLAST FROM THE PAST]

Agree with this very much. I remember you saying long ago that any cold is likely to come from the NE, and I agreed. I cannot see any blocking to the NW. the Russian high is very large, and definitely an ally IMO. Its definitely possible we could see some HP over Greenland, but its going to definitely be from the east initially. The met also think its going to be a NE block (presumably)

Its about where it starts IMO, if we get there a GHP will develop as retrogression continues, but I don't see a Dec2010 scenario

BFTP

[LomondSnowstorm]

Mean troughing further east than at 12Z with the Russian high extending its influence further west. We're getting there.

[stratty]

GEFS control has gone made and brings in an E,ly at +204.

http://modeles.meteo...-0-1-204.png?18

LP moves SE!

I sense this LP is going to drive us mad over the next few days.

Try member 5 too! Nice easterly - again early in the run The Goldmember?!

[TEITS]

Typical madness from the ensembles. You thought the control was crazy but member 5 brings in an E,ly at +144 lol.

[john pike]

http://www.wetterzentrale.de/wz/pics/brack4.gif

good updated fax chart for 120 (mon 22nd)

528 dam line across the whole of the uk

north-north westerly winds

[Tom Quintavalle]

http://cdn.nwstatic.co.uk/gfsimages/gfs.20120118/18/177/h500slp.png

http://www.ibiblio.o...unch.scream.jpg

Regards,

Tom.

Edited January 18, 2012 by TomSE20

[damianslaw]

Last post from me - yes the trough digging SE looks very likely but possible not before we see heightrs ridging NE across the country and into scandi. There are signs already that the jet is tilting NW-SE, we have lost the w-e, and indeed sw-ne tracking jet, take this weekend the models continue to show the trough tracking more SE, not far enough yet to pull in cold from the NE but enough to bring some much colder uppers.

I suspect the set up below will occur next week -

Azores high quickly builds NE behind a trough/low pressure system early next week, this then quickly ridging NE into scandi by the end of the week creating the foundations for proper SE trough displacement.

The other possibility but less likely to occur is for trough/low pressure to dig SE into central europe as the azores high retrogresses NW, we then see a cold injection of air from the northeast as heights build to our NW.

Of course we could still see a similiar set up to what we have now, i.e. the azores fails to retrogress NW or ridge NE - but there are too many signs suggesting amplification of the jet and a meridional pattern taking hold.

I see the azores high as being pivotal to a colder evolution - ideally we want it to either ridge NE or retrogress NW rather than remain stuck in situ.

[nick sussex]

Typical madness from the ensembles. You thought the control was crazy but member 5 brings in an E,ly at +144 lol.

http://modeles.meteo...-5-1-144.png?18

Yes can we just get on with this and get the show on the road!

I'm really losing patience with this winter and don't feel like watching that trough sit over the UK and decide whether it wants to eject some energy se'wards.

Especially as it didn't have the decency to start off negatively tilted! I promise thats the last of my negative tilted troughing talk until tomorrow!

[492]

I would like to know what the wavelength is around the northern hemisphere at the moment at 500MB. I seem to remember that if is more than about 4000 miles the waves start moving backwards and we have retrogression. From the charts available it is difficult to measure

[TEITS]

Scatter on the ensembles starts as early as +96.

http://176.31.229.228/modeles/gens/graphe_ens3.php?x=306&ext=1&y=141&run=18&ville=Londres&runpara=0

Considering the 18Z and the fact that the Met O have gone with the UKMO suggests to me that we may yet see an improvement around the +96/+120 timeframe. What I mean by this is a colder N,ly flow rather than a cool NW,ly. Something to ponder for tomorrow mornings 0Zs. Seems to me the models are going back to showing the jet alligned NW-SE rather than W-E as previously modelled.

[Zakos]

In terms of the met office's two possible scenarios, I'd say its still up in the air, but today has seen a notable shift towards the colder evolution from the models.

I'd say its slightly more probable now that we'll see cold, rather than the other round which the met suggested a few days ago

[patrickshere]

The +384 is absolutely hilarious.

Superlow vs Russian high.

Round 1, fight.

[feb1991blizzard]

GEFS member 20 is a stonker, a really strong block with the -12 uppers into the south east and the -8's over a huge portion of the UK for most of the last 160 hours.

http://www.meteociel...8&mode=0&carte=

Pity its not the operational and the 1st 160 hours!, although given the last week would it even be guaranteed then!!!!!!

Edited January 18, 2012 by feb1991blizzard

[Zakos]

The +384 is absolutely hilarious.

Superlow vs Russian high.

Round 1, fight

GFS simply doesn't know where to place the Russian high, so it panics and spawns a super low via the "default to zonality" button lol

[john mac]

Last one for mr tonight. Nice to finish on a good note today with the 18z the ensembles and the fax charts moving in the right direction. Dave i agree with you about the northerly as the models are catching up still so there could well be a significant upgrade in the shorter term,

[Duane S.]

I'd have to say not really any wiser today if the op runs are anything to go by!

Just for fun have a look of this. Like a little tent of warmth, almost perfectly following the contours of the British Isles!...

Edited January 19, 2012 by s4lancia

[syed2878]

Hi nick can u give me the link to the noaa disc plz. Thx.

[syed2878]

cant edit the post. I meant the daily disc plz. Thx.

[PolarWarsaw]

So the 0z runs for the morning up and running. Wonder whether things will take a swing towards a colder or a milder evolution today?

[Snowy Easterly]

alright radders lets hope for the best

this post will get deleated later i bet

[PolarWarsaw]

http://cdn.nwstatic.co.uk/gfsimages/gfs.20120119/00/84/h850t850eu.png

Looks as you were so far, PV looking slightly less intense/widespread

[Snowy Easterly]

medicore run so far, that big low in the atlantic looks further east, not sure what happens after

cold uppers on tue are shunted out to the north sea

Edited January 19, 2012 by Snowy Easterly