Model Output Discussion - Stormy Period Inbound...

[JoeShmoe]

I know people are desperately searching for snow at T+360 but the weather is nevertheless interesting and that storm on GFS next week is potentially record breaking and destructive. Im meant to be on a plane from Edinburgh to London that day 

[winterof79]

I think i will make the most of my last few days in Yorkshire as i knew it.

http://modeles.meteociel.fr/modeles/gfs/runs/2015010906/gfs-0-144.png?6

[mushymanrob]

 

So, when I see these classic patterns that bring rain & snow I know straight away the South is out of the game, however IMBY aside its proper North West Midlands, Derby Peaks, Welsh hills & Pennines type snow events coming along, with the peppering of Wintry & snow showers effecting NI & the NW as well as Scotland.

 

 

sorry old chap, i think youre being premature there. theres alot of cold potential in the outputs, with increasing incursions of pm air lasting longer and digging further south.

the atmosphers is in a very volatile mood, its very unsettled, and with increasing cold incursions i certainly wouldnt write off the south getting snow in the next few weeks. ok it might not be as likely as more northern areas, but it only takes a channel low..

[IDO]

sorry old chap, i think youre being premature there. theres alot of cold potential in the outputs, with increasing incursions of pm air lasting longer and digging further south.

the atmosphers is in a very volatile mood, its very unsettled, and with increasing cold incursions i certainly wouldnt write off the south getting snow in the next few weeks. ok it might not be as likely as more northern areas, but it only takes a channel low..

 

The snow percentage graphs says 20% on one day is the best chance but mainly 5-15%. So in reality then maybe the Downs and other hilly areas may get something but overall nothing has changed; it is mainly Midlands North increasing with ASL for any frontal or LP snow though even the north are borderline for this. Plenty of PM snow showers for the NW (including Ireland) though.

 

The GFS 06z op sends more energy over the (potential) ridge at D7 so this looks of little interest: 

 

The GFS P has now also seen the short wave spoiler and makes less of any heights after D7 compared to the 0z:

 

 

GFS op at D14 is much flatter than the 0z: 

 

Still a cold trough of 850s so potential in the north for snow but down south frontal rain, though snow flurries can never be ruled out.

Edited January 9, 2015 by i'm dreaming of...

[knocker]

Looking at the latest EC32 output after the 21st I can't see anything significantly different, perhaps a period with more influence from the Azores HP, but generally LP to the NW and pretty zonal with temps average or a tad below. Certainly no indication of any lengthy cold period. Of course this is pretty broad brush and at this stage doesn't indicate the proportion of the Pm and Tm influence which is what it appears to boil down to.

[IDO]

Looking at the latest EC32 output after the 21st I can't see anything significantly different, perhaps a period with more influence from the Azores HP, but generally LP to the NW and pretty zonal with temps average or a tad below. Certainly no indication of any lengthy cold period. Of course this is pretty broad brush and at this stage doesn't indicate the proportion of the Pm and Tm influence which is what it appears to boil down to.

 

Yes ties in with the JMA and CFS week 3-4 outlooks. Normally I would expect very little from this setup in the next 16 days but we are seeing the 850s PV axis favour us by edging east so we benefit from the cold ejecting from the core cold closer to the UK so more potent than the usual PM flow:

 

 

 

As the LR and Dr Cohen indicates no real pattern change though a reduction in the zonal intensity is welcome during week 2.

[mulzy]

sorry old chap, i think youre being premature there. theres alot of cold potential in the outputs, with increasing incursions of pm air lasting longer and digging further south.

the atmosphers is in a very volatile mood, its very unsettled, and with increasing cold incursions i certainly wouldnt write off the south getting snow in the next few weeks. ok it might not be as likely as more northern areas, but it only takes a channel low..

 

I think Steve is on the money here.  Good model support for his views currently.  Of course things can change fairly quickly but for now a finessing of the pattern rather than the pattern change that we coldies really need.

[IDO]

 

The GFS P (as it will) offers a teaser at the end of FI with Artic air and some very cold uppers close to N Scotland. Again the signs are that it is a toppler (usual caveats):

 

 

And as we know GFS P tends to over do these ridges in FI and downgrade as it moves towards T0.

 

Anyway at least some interesting weather in the next two weeks.

Edited January 9, 2015 by i'm dreaming of...

[Jason M]

I think Steve is on the money here.  Good model support for his views currently.  Of course things can change fairly quickly but for now a finessing of the pattern rather than the pattern change that we coldies really need.

Who'd have thought it? Mushy ramping :-) Frosty missed a great chance here IMHO :-)

Think you and Steve are right here. I have known snow down here in these set ups but its rare and in terms of significant snow, I'd say very rare. I haven't looked at the 06Z GFS yet, but taking into account all the output this morning including GEFS, GEM ensembles, a continuation of zonal looks the best bet (albeit with less certainty).

I think BA might be on the money in terms of where we will eventually end up, but I have a hunch it won't be much before the last week of Jan, early Feb. In the meantime if your on high ground in the north, a fun couple of weeks maybe coming up.

[winterof79]

gfs-0-348.pnggfs-1-348.png

 

The GFS P (as it will) offers a teaser at the end of FI with Artic air and some very cold uppers close to N Scotland. Again the signs are that it is a toppler (usual caveats):

 

gfs-0-384 (1).png

 

And as we know GFS P tends to over do these ridges in FI and downgrade as it moves towards T0.

 

Anyway at least some interesting weather in the next two weeks.

The GEFS offer quite a few height rises accross the spread

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

[karlos1983]

I've always liked and held that CFS model in high regard 

 

honest!!

[IDO]

The GEFS offer quite a few height rises accross the spread

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

 

It was similar about 5-7 days ago for the upcoming D8 height rise, that has now been watered down as we draw towards T0. I was suggesting in this repeating pattern it is more than likely that again this will be the case for the height rises at the end of FI. Bearing in mind that GFS have us entering MJO phase 7 whilst support for this is not convincing then that would temper those height rises even more. Though of course other variables may change this pattern by then.

[bluearmy]

gfs-0-348.pnggfs-1-348.png

 

The GFS P (as it will) offers a teaser at the end of FI with Artic air and some very cold uppers close to N Scotland. Again the signs are that it is a toppler (usual caveats):

 

gfs-0-384 (1).png

 

And as we know GFS P tends to over do these ridges in FI and downgrade as it moves towards T0.

 

Anyway at least some interesting weather in the next two weeks.

That back end gfsp chart you posted is an Atlantic view. The NH profile could be seen as a trend ???

Again, perhaps premature but it shows the trop nwp with a propensity to go in this direction.

[IDO]

That back end gfsp chart you posted is an Atlantic view. The NH profile could be seen as a trend ???

Again, perhaps premature but it shows the trop nwp with a propensity to go in this direction.

 

Yes the GFS P NH profile is nice:

 

However P's tendency to over amplify since it started running, when it sees a pattern change, is alarming, so a comparison with the OP is best:

 

 

BIG differences.

 

The GEFS at D14 shows a similar pattern as December:  

[winterof79]

Any showers on Saturday will be wintry and i do not think Euro4 will have the exact track/train of showers nailed by a long way.The flow will be unstable and the Irish sea will have a big say in the amount of precipitation

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/01/09/basis06/ukuk/taup/15011100_0906.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/01/09/basis06/ukuk/th85/15011100_0906.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2015/01/09/basis06/ukuk/prty/15011100_0906.gif

[Summer Sun]

Continued hints of some snow for England during next week from GFS P it has to be said though NW Scotland looks the place to be for snow with over 12inches in places

 

By 13:00 Sunday the snow is starting to mount up for NW Scotland with up-to 5cm for SW Scotland and NW England lower parts could also see some snow later tomorrow as temperatures plummet from around 13c to just 2 or 3c tomorrow afternoon in the north

 

 

By 13:00 Monday most of the snow has melted but don't worry more is coming

 

 

24 hours later the snow is quickly mounting up again with 7 inches (19cm) in parts of NW Scotland snow starts to become more widespread again with a dusting possible as far south as Dartmoor

 

 

Fast forward another 24 hrs to 13:00 Wednesday and the snow keeps on building for NW Scotland with the highest totals just short of 1ft snow in the south west starts spreading up towards Bristol but even places as far east as reading could see a dusting

 

 

By Thursday the south looses the snow with NW Scotland also seeing a slight reduction with the highest totals down to 26cm (11 inches)

 

 

The snow soon returns as we move into Friday with parts of the south west seeing a slight covering highest totals in NW Scotland are back upto 39c (15 inches) further east in Aviemore totals here are around 7 inches (18cm)

 

 

Now skipping forward to the 18th a large stretch right down to the south coast sees a dusting back up in NW Scotland the highest totals look fairly stable whilst over in Aviemore a slight increase to 21cm (8 inches) is shown

 

 

All in all we have continued hints of some snow for parts of England next week just need to see how things develop over the next 48 hrs or so

[linarite]

I hope those pressures modelled on the 06z GFS para for wed/thur next week turn out to be wrong (935mb central pressure??!!).  As currently shown this would be a catastrophic event

 

[bluearmy]

Yes the GFS P NH profile is nice: gfsnh-0-384 ( .png

 

However P's tendency to over amplify since it started running, when it sees a pattern change, is alarming, so a comparison with the OP is best:

 

gfsnh-0-384 (9).png

 

BIG differences.

 

The GEFS at D14 shows a similar pattern as December:  Meteociel_-_Panel_GEFS 17.png

IDO, I see you are sticking with the Atlantic on the gefs windows. The NH profiles look far more interesting. At such a range, the bigger picture is often more revealing. no clustering of note but a picture which reveals quite a disturbed vortex as we enter the last quarter of jan.

[Hotspur62]

Thought we might have seen a movement further West of the AH in the last couple of runs of models and whilst GFSp does this, the GFS and ECM don't. The difference is vast when you look at what GFSp and GFS produce(albeit in FI) and I just think as others have stated that will be in a cool/coldish zonality for at least next 10 days. Still think last week and Feb hold good potential for UK wide snow and cold but we have been there before so nothing is a done deal yet . In the meantime those who get snow on weekend and next week,enjoy it. Those, like me(I fear) who don't, hang in there and keep positive

[IDO]

IDO, I see you are sticking with the Atlantic on the gefs windows. The NH profiles look far more interesting. At such a range, the bigger picture is often more revealing. no clustering of note but a picture which reveals quite a disturbed vortex as we enter the last quarter of jan.

 

Yes, but I am fed up with the "big picture" this winter

 

Looking for some IMBY changes

 

So I am rather hesitant to anything  before Feb   

 

  Though as you say it could be worse 

[karyo]

I have to say that I agree with IDO about the GFS P tending to over amplify the pattern in FI. This makes the model for me quite unreliable and this needs to be sorted before it replaces the original GFS.

 

On a different note, interesting day tomorrow with the sharp transition from very mild and wet to showery and cold. Western areas should enjoy a fair few snow showers but with the warm ground temperatures I doubt any of it will settle away from high ground. 

Edited January 9, 2015 by karyo

[karlos1983]

I hope those pressures modelled on the 06z GFS para for wed/thur next week turn out to be wrong (935mb central pressure??!!).  As currently shown this would be a catastrophic event

 

Personally I hope they do verify, at least it would provide some interesting weather, for which has lacked big time in the south. 

[Carlrg]

The massive Atlantic HP block unfortunately seem to have gone by the wayside now in most of the models even in FI. Looks like a Polar Maritime flow for the foreseeable future. I think a SSW will be needed to get us out of this coolish rut we are in. Nothing spectacular,    (for cold that is) not wind.

Edited January 9, 2015 by Carlrg

[IDO]

  MattHugo81

If you believe the EC32 model then the outlook is grim if you want a bit of 'winter weather' +NAO pattern/mild, wet and windy through to Feb

09/01/2015 12:33

 

Close to Knocker's take on the EC32.

 

The ECM extended London temps suggests nothing very cold:

 

  ...same De Bilt: 

 

Clearly more seasonal than some winters but the south could struggle before Feb to get anything wintry.

[mountain shadow]

  MattHugo81

If you believe the EC32 model then the outlook is grim if you want a bit of 'winter weather' +NAO pattern/mild, wet and windy through to Feb

09/01/2015 12:33

 

Close to Knocker's take on the EC32.

 

The ECM extended London temps suggests nothing very cold:

 

 ensemble-tt6-london (9).gif ...same De Bilt: eps_pluim_tt_06260.png

 

Clearly more seasonal than some winters but the south could struggle before Feb to get anything wintry.

 

 

To be fair it will be wintry enough in the North and West even though the NAO will be positive, if only because the troughs will be getting East of the meridian. Cold zonal in the North and West, with average zonal towards the South and East until month end.