Winter Model Discussion - The Hunt For Cold -18z 17/12/12

[Troubleatmill]

Over all a better gfs , that is until it get to 192z and then as per usual it goes into default mode which is really annoying because you can litterely watch as soon as it goes into low res it bumps up the jet and brings in the Azores and once again gives us southwesterlies , absoulute joke, but over all it's a nice step in the right direction.

i actually believe the azores high is the last player to come to the table and isnt our enemy, everything else has go to wrong before this, by its very name doesnt want to be here, of course he is more than welcome to holiday here summer

Edited December 19, 2012 by Nick JB

[swilliam]

Control run from the GFS is looking very nice in FI.

Edited December 19, 2012 by swilliam

[Panayiotis]

Let's just say that if the ECM 240H was to come to fruition, I would say that this chart is a serious step in the right direction.

With a high pressure like that building over greenland, it would only be a matter of time before we got locked into cold. Because it would avert our usual atlantic tracking low pressure systems up the western side and over the blocking high. That pressure on the high would probably have it squeeze south and possibly leave us in a north easterly/easterly air flow!

A long way away but will be nice to see if the 12z ECM can follow this route.

Nice chart from the ECM, this is similar to what the GFS is showing now and it was almost exactly a match a couple of days ago.Since I spotted this trend on Saturday I noticed that the Bering Sea high, is migrating over the Arctic. Depending on where it goes, depends on the weather we get, in this case it has moved to Greenland (my preferable location but i cant control the weather!) and linked up with the Azores High, very glad the ECM is now showing this and hopefully the trend continues in the positive direction! Edited December 19, 2012 by Panayiotis

[Harsh Climate]

Yes I'm eagerly awaiting tonight's ECM, If it continues this short trend towards height rises in Greenland tonights 240 could be very nice indeed..

[Panayiotis]

After Christmas, im more confident we will see another cold spell as a lot of the perturbations are heading for this idea, the watch continues...... http://www.meteociel...=0&mode=1&ech=6

Edited December 19, 2012 by Panayiotis

[Glacier Point]

Exactly what I'm thinking Ian. (see my previous post). More time wasted IF it comes off like that.

What I will say is that even though the picture is changing between runs, the high to the south is consistently modelled and very often is being modelled throughout the duration of FI. We'll struggle to get any meaningful cold with this feature in place. It needs to do one from the output!

The upstream uncertainty of the storm track across the US makes the operational GFS a very limited tool at the moment. CPC have cited horrible performance of the ops of late.

Ensemble means are a bit fluid, and some health warning on these, but for what it's worth, day 8 GEFS H5 mean anomaly puts the UK more in with the Scandinavia trough (note the absence of the strong +ve heights to our south there). Not abundantly cold, but the control demonstrates an option in with that troughing.

[bluearmy]

A fairly strong theme in the GEFS of a cool/cold trough around the uk for the late xmas/new year period. surprises from that with disturbances running west to east. we do need to get some low uppers in though - maybe not as low as you might imagine if its slack and the heights are v low.

[AWD]

Control run from the GFS is looking very nice in FI.

It's not an outlier either. At the cold end of the members at times, yes, but with enough support for it to be considered a valid option;

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres

http://www.meteociel.fr/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=0&type=3&ext=1

Edited December 19, 2012 by AWD

[UV-RAY]

A fairly strong theme in the GEFS of a cool/cold trough around the uk for the late xmas/new year period. surprises from that with disturbances running west to east. we do need to get some low uppers in though - maybe not as low as you might imagine if its slack and the heights are v low.

Some cold zonality for a few days would be most welcomed in this neck of the woods, I may even see some of the white stuff for the first time in twelve months.

[Panayiotis]

Very, very nice ensemble with the mean dropping below zero (for my area), on Christmas day. Interesting is the word i would use for after Christmas! http://modeles.meteo...13205&runpara=0

Oops AWD beat me to it! :L

To put it into perspective here is yesterday's 18z ensemble, showing how today is an upgrade in terms of cold. http://modeles.meteo...13205&runpara=0

Edited December 19, 2012 by Panayiotis

[chris55]

Love this chart, all a little further east than this mornings 00Z run and with a stronger High to the North West, A few tweaks here or there maybe a slight ridge from the Atlantic and we could see an extremely cold northerly develop!! So much better to see the chunk of the PV modelled to our east and not over Greenland.

[nick sussex]

It's funny how one synoptic feature goes from hero to zero ! The Russian high is now Satans offspring! These forums are brutal!

I think really its a case of hoping the pattern is edged east, regarding the ECM although that had a decent pressure rise to the nw on the 00hrs the only thing celebrating that would be cold loving fish in the mid Atlantic!

You do not want to see a stretched troughing running sw/ne as this will just have the effect of pushing the Azores high towards the UK.

Our new Xmas Miracle will be no western based negative NAO, we need positive anomalies further east.

I see SM summed up my thoughts in one sentence rather than my more longwinded ramblings!

Edited December 19, 2012 by nick sussex

[AWD]

Strong cluster going for colder weather in the Aberdeen suite;

http://meteociel.com/cartes_obs/gens_display.php?ext=1&lat=57.2&lon=-2.3

Notice the mean near -5c throughout FI.

[snow1975]

Snow event for Scotland

[wolvesfan]

Evening all,

I quite like the ECM 500mb mean at day 10,http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

The east Canadian block funelling cold air from the Arctic which feeds the trough to the SW of the uk,Azores high is ridging into spain but props up further trough over the UK,dosn't look like a mild feed to my untrained eye.wouldn't there be a lot of cold air in the mid atlantic?

[lorenzo]

Adios Boris we now have a new villain in the pantomime.

[chris55]

Could the Atlantic ridge bring in the northerly? Or will the Low push though?

Russian high weaker and further east as well,

Edited December 19, 2012 by chris55

[chionomaniac]

There is a slight hint on the ensembles that the west based -ve NAO may become more east based as we enter Jan - one to keep an eye on this.

http://raleighwx.ame...ensindices.html

Edit: just seen your villain, Lorenzo. Ha!

Edited December 19, 2012 by chionomaniac

[Summer Sun]

GFS 12z ensembles give some hope again after Christmas

Plenty of members trending cold

[Barmada Casten]

so the models are pointing out potential cold after Christmas then.....

[nick sussex]

Evening all,

I quite like the ECM 500mb mean at day 10,http://www.meteo.psu...0z/hgtcomp.html

The east Canadian block funelling cold air from the Arctic which feeds the trough to the SW of the uk,Azores high is ridging into spain but props up further trough over the UK,dosn't look like a mild feed to my untrained eye.wouldn't there be a lot of cold air in the mid atlantic?

And thats where it will stay!

We need the pattern much further east and south. The ECM 00hrs only looked good if you're in a trawler in the mid Atlantic, given the recent letdowns surely the weather Gods will just be kind and not stick the core of the high too far west.

[chionomaniac]

The upstream uncertainty of the storm track across the US makes the operational GFS a very limited tool at the moment. CPC have cited horrible performance of the ops of late.

Ensemble means are a bit fluid, and some health warning on these, but for what it's worth, day 8 GEFS H5 mean anomaly puts the UK more in with the Scandinavia trough (note the absence of the strong +ve heights to our south there). Not abundantly cold, but the control demonstrates an option in with that troughing.

Worth mentioning that an absence of heights to the south is also in keeping with the MJO phase - therefore, would be surprised to see these become a significant problem.

Edit: And ECM T+120 has lower heights to our south and the trough is pushed further east to reinforce this.

Edited December 19, 2012 by chionomaniac

[Harsh Climate]

Looks good to me so far

[chris55]

Russian/Scand high well to the east compared to the 00z, everything a little more east as a result.

[Harsh Climate]

If this trend continues certainly the chance of wintry precipitation into northern ireland late christmas day!