Model Output Discussions 06z 04/11/16

[BLAST FROM THE PAST]

1 hour ago, Ed Stone said:

As I said yesterday - it's only November. 

The ECM shows the potential for persistent freezing fog, a discombobulated PV and the chance of significant snow, this side of Christmas...What more do you want - an F5 tornado descending on the Houses of Parliament?

Well they had a nice one in Wales today...??

 

BFTP

[Frosty.]

16 minutes ago, snowwman said:

A retrogresssion of heights to Greenland is what I'd expect.

It's what most of us are hoping for but not necessarily expecting but there are signs of retrogression again today on the GEFS 00z / 6z / 12z and potentially the 18z too. My hope is the support will eventually become overwhelming for height rises to the nw, a mid atlantic ridge or better still, a mid atlantic high building north and linking up with the Greenland high and at the same time, the formation of a robust scandi trough..not asking for much am I!

Edited November 17, 2016 by Frosty.

[tinybill]

5 minutes ago, Frosty. said:

It's what most of us are hoping for but not necessarily expecting but there are signs of retrogression again today on the GEFS 00z / 6z / 12z and potentially the 18z too. My hope is the support will eventually become overwhelming for height rises to the nw, a mid atlantic ridge or better still, a mid atlantic high building north and linking up with the Greenland high and at the same time, the formation of a robust scandi trough..not asking for much am I!

just  looked  at f1  on the  gfs  early dec is looking interesting  to say  the  least, and  as  for  sunday its  looking  very wild   for some  parts  of  the  u.k.

[Zakos]

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GFS has been hinting at retrogression to Greenland/Hudson consistently for 4 days now.

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It first picked up on the signal over a week ago. I personally also think the ECM is wrong, retrogression of the block to this area is most likely scenario IMO.Question is, will there be enough blocking in the Atlantic to maintain a cold air flow for the UK?

Edited November 17, 2016 by Zakos

[Frosty.]

4 minutes ago, tinybill said:

just  looked  at FI on the  gfs  early dec is looking interesting  to say  the  least

I couldn't agree more, the Gfs 12z later in low res is my idea of wintry heaven, and it has some support from the GEFS 12z.

Edited November 17, 2016 by Frosty.

[nick sussex]

The largest spread in the ECM ensembles on days 9 and 10 is over Iceland and southern Greenland.

 

 

[Man With Beard]

    

Little sign of a euro high on those. Still risk of something dropping down from the north with a rebuild of height behind.

I did spot a couple of potential Scandi Highs on the GEFS ensembles, too.

 

[knocker]

A quick look at NOAA this evening

The 6-10  has the ridge orientated SW/NE to the west of the UK with the main anomaly to the NW and the cut off upper low over Iberia, A familiar set up. Essentially this leaves the UK either in a col situation or a slack or easterly air flow with the surface low pressure area to the south. I would expect  as we go forward for the pattern to weaken somewhat, although staying essentially similar, with the HP anomaly slipping west. This still leaves periods of unsettled weather, perhaps more confined to the south, with temps variable but generally around average. The GEFS is not adverse to this in the 6-10 period but rather more keen to retrogress the ridge in the latter period with a trough over the UK.

[TSNWK]

5 minutes ago, nick sussex said:

The largest spread in the ECM ensembles on days 9 and 10 is over Iceland and southern Greenland.

 

 

Welcome Nick! I think that a positive for the Greenland high option? As it suggests nothing is certain over there to content this evenings op?

Edited November 17, 2016 by TSNWK
Spelling

[bluearmy]

6 minutes ago, nick sussex said:

The largest spread in the ECM ensembles on days 9 and 10 is over Iceland and southern Greenland.

 

 

 I believe those spreads are towards the low side, representing deepish systems passing across the top of the mid lat ridge

extended eps tell the same story with expanding sceuro low anomoly taking hold post day 12 and no sign of any greeny ridging on the means/anomoly. That seems to be firmly holding over hudsons. My expectations from earlier this afternoon are unchanged. 

Edited November 17, 2016 by bluearmy

[Frosty.]

Tonight's Ecm 12z ensemble mean shows plenty of chilly weather in the coming days with sunshine and showers, some heavy with hail & thunder and cold enough for sleet and wet snow on hills but on some lower ground too in the heavier showers and nights look cold with frosts where skies clear. It becomes very unsettled for most of the uk this weekend with wet and windy weather and a chance of hill snow on the northern edge and back edge. Into next week it starts chilly with showers but the trough over the uk gets squeezed, gradually fills and is replaced by an area of high pressure by day 6/7 which becomes centred over the uk with variable cloud and sunny spells but with cold frosty nights with fog forming, some of it dense and freezing which would also be slow to clear.

Edited November 17, 2016 by Frosty.

[bobbydog]

Whilst I haven't got much to add to the thread tonight so far, as the output is in a bit of 'limbo' mode at the moment, reading through the posts of our regular contributors, it occurred to me that considering recent output, we haven't heard from johnholmes. He is often the voice of reason when the 'silly season' is here and I do hope all is well with him.

[BLAST FROM THE PAST]

hmmmmmm...18z is doing an ECM

 

BFTP

[booferking]

2 minutes ago, BLAST FROM THE PAST said:

hmmmmmm...18z is doing an ECM

 

BFTP

GFS has been back tracking since yesterday ECM looks to be the form horse.

I thought the GFS was the short wave king.

[weatherguy]

Hmm...

+129 gfs12z  

same time frame 18z 

 

Leaning more towards the ECM solution it would seem.

 

What we need to watch for is whether the ridge will hold long enough to consolidate the low heights over europe.

 

Edited November 17, 2016 by weatherguy

[Ali1977]

Less ridging/WAA in the pub run, I can't help thinking that after the block over the UK forms we may end it dragging a Northerly flow quicker than the 12z. The colder air is closer to our North at 144 so we just need to see at what point the high heads NW- if it does,  and if the Northely flow heads straight for us. 

Also to note is the Siberian high is being pushed SE out of the way slightly faster , maybe assisted by a stronger Arctic high forming.

Edited November 17, 2016 by Ali1977

[Zakos]

Arctic High has been beefed up a fair bit on the 18z, aswell as blocking over Canada

Edited November 17, 2016 by Zakos

[Geordiesnow]

This run may be leaning towards the ECM but it looks similar to the 12Z run and we kind of have some agreement on how the outlook may play out but as per usual its a case of nailing down the details.

Low heights across Iberia, high pressure over Iceland, question will be just how much of that high topples in and secondly how much cold air will get trapped under that high if it does? If we get that slack northerly flow just like the ECM then the high topples in, we could be looking at some quite cold nights and harsh frosts, if it struggles to topple in, then we will stay cloudier with a raw easterly.

On pure weather terms, I would hope the ECM occurs, easterlies are not all that nice if they are not the showery convective type which this easterly won't be due to high thicknesses and high uppers and frost/fog will certainly be a lot more seasonal.

[Glacier Point]

Ec32 maintains weakish +ve height anomaly to NW week 3, becoming stronger week 4. Scandinavian trough signal throughout weeks 3 and 4. Not so different from that composite I posted earlier on. AO negative throughout and noted downward trend on 12z EPS

[Bullseye]

Interesting tweets last few days from Michael on Twitter especially this one tonight. Would be interesting lead up to Christmas period and is that more central based NAO than West?

 

[Snowy L]

Low pressure established in Iberia/ North Italy, Russian high beginning to be cut off from UK high, Atlantic high pushing into Greenland. Looking good so far.

Edited November 17, 2016 by Snowy L

[Barry12]

First it was the middle of November, then the end of November, and now the start of December for the pattern change to significant blocking! Let's hope this isn't a theme of this winter as I have dejavu of this thing happening  from the last couple of winters. A couple of days ago Ian posted about a strong signal towards a more blocked pattern, with GLOSEA and MOGREPS both supporting that. But less than 24 hours later, the signals towards a more blocked pattern had already waned, which goes to show just how hard it is forecasting the weather anymore than a week in the UK. I'm currently not getting excited just yet as all the blocking charts seem to be remaining in the 10-15 day timeframe. The GFS 12z run everyone was getting excited about has already changed  on the 18z. The Northern Hemisphere background does still look much better than last year, but all the good background signals in the world don't gurantee cold/snowy weather for the UK. Until these blocked/cold charts get to at least day 7, theirs no point getting too excited in my opinion.

 

[swfc]

at 192 check out the tip of greenland on the 12z to the 18z .change a foot on this run.scandi high for me 

[Ali1977]

It's taking a little while longer than I hoped, and I'm not sure what form it's coming, but the NH looks full of promise for Dec...Just look at the lack of PV and the crazy jet stream. Winter is coming for sure. FI this run looks interesting too. 

High building into Greeny - cold about to flood south straight for us I reckon.

Edited November 17, 2016 by Ali1977

[Eskimo]

Looks much better than the 12z in my opinion. Cold swooping down from the Arctic, high building up to Greenland. 

Edited November 17, 2016 by PerfectStorm