Model output discussion - 5th December 2016 - Into Winter we go

[IDO]

42 minutes ago, That ECM said:

Now there's a chart full of potential 

 

it has carried forward a similar idea to be fair. 

 

 

When I start trusting a day 10 ECM chart please call the men in white coats for me. Looking at how it smashes the PV to pieces from D8 to D10 is just not the most likely outcome IMO:

Where as the other models continue with the general trend of slippage from Siberia to NE Canada; D10:

So I suspect wise to ignore ECM op past D8 till it gets some support and I suggest the D10 scenario it plays out has some small cluster support, but as the way with the ECM, the op tends to pick the smaller clusters of its own suite in such set ups to sit in (the GEFS have a small cluster vaguely similar). So not impossible but an outside bet.

Other than that it is hard to be confident after D10 (or before), with that strong -ve EPO squeezing the PV. Will it break the PV up, maybe with a second Atlantic wave being a bit more resilient, or will it simply push the PV around the remaining NH profile? The UK therefore would certainly remain in a colder upper air pattern, but that is as far as i would go re specifics; long wave let alone short wave. The D16 chart still holding onto the -EPO so potential for seasonal first half of January at least.

Interesting stuff although no nearer this morning as to the second shot, though the first push of cold air NY day looks like bringing some strongly below average daily highs. The cold front that heralds in that air looks like rain for all apart from very favoured locale, with showers to coastal regions thereafter. 

[Man With Beard]

Morning all, headlines unchanged for the short-term, a window of about 48 hours coming up for low-level snow, though no guarantee any one location will see snow apart from locations affected by on-shore winds. 

Further out, still could be looking at a reload between D9 and D13 but also a new possibility this morning, where heights build tentatively towards Scandi creating a small risk of deep cold from the east (probably unsuccessful) - these heights threaten to derail further height rises towards Greenland resulting a slightly flatter pattern by D10.

So one to watch through the day. Happy model watching

 

[stewfox]

1 hour ago, Newberryone said:

 9pmay tracking around the area of high pressure for those further northwest would probably suggest alright why Met Eireann in their latest update this morning are now talking about the high probability of this being a short cold snap from Sun-Tues inclusive with a return to less cold or even milder south westerlies by next Wed. 

Gfs 0z has 1c at my location next Wednesday at  9pm. Do you have a link ?     

Edited December 28, 2016 by stewfox

[Sky Full]

We can now be confident of seeing a spell of colder but still quite settled weather from News Years day as shown by the GFS:

 

and for anyone who feels disappointed that this is not quite as severe or long lasting as the models were predicting a week ago, take a look at what was awaiting us at this time last year.....

 

Personally, I would take the current conditions over those we were suffering last January - we are actually very lucky this year to have avoided all those Atlantic storms (although I suppose there's still time....!).

 

[bluearmy]

IDO, the movement of the mean eps around days 9/10 towards where the op is now (re the hangback of heights se from the Atlantic ridge ) is more than just notable and illustrates what I posted yesterday evening before the eps came out. you dismiss the global picture painted on the op days 8/10 but you shouldn't do that closer to home. whenever the op is consistently away from the ens in that period, it is wise to take note of it. It could be wrong but it shouldn't be dismissed. We now see the eps take a stride towards the op which means that the sceuro trough is shifted east and the Atlantic ridge the same in the 9/11 day period.  i noted that the London temps have shown two runs in succession of the op looking to be on the warm extreme around 4/5th Jan. Suspect that won't be the case today and thereafter. 

whilst the extended eps may again revert to wintry nirvana, until you get within the operational at day 10 for a run or two, you can't know where the corrections to the background pattern are likely to be. To me, it looks like pretty well all the NH is right on the eps apart from the Euro heights which are proving painful - again! 

[northwestsnow]

Well i will probably be in the minority here but i would prefer Gfs over Euro this morning.Gfs brings cold zonality as the jet heads south and we lose those awful euro heights.

[mulzy]

Bad news folks - it seems that the extended eps have flipped to what looks like a positive NAO.  Nowhere near as good as last night's set.  Let's see if this repeats itself tonight.

[feb1991blizzard]

Just now, mulzy said:

Bad news folks - it seems that the extended eps have flipped to what looks like a positive NAO.  Nowhere near as good as last night's set.  Let's see if this repeats itself tonight.

Yes I guessed that from the disastrous downgrade on the day 10 mean chart.

[northwestsnow]

2 minutes ago, bluearmy said:

IDO, the movement of the mean eps around days 9/10 towards where the op is now (re the hangback of heights se from the Atlantic ridge ) is more than just notable and illustrates what I posted yesterday evening before the eps came out. you dismiss the global picture painted on the op days 8/10 but you shouldn't do that closer to home. whenever the op is consistently away from the ens in that period, it is wise to take note of it. It could be wrong but it shouldn't be dismissed. We now see the eps take a stride towards the op which means that the sceuro trough is shifted east and the Atlantic ridge the same in the 9/11 day period.  i noted that the London temps have shown two runs in succession of the op looking to be on the warm extreme around 4/5th Jan. Suspect that won't be the case today and thereafter. 

whilst the extended eps may again revert to wintry nirvana, until you get within the operational at day 10 for a run or two, you can't know where the corrections to the background pattern are likely to be. To me, it looks like pretty well all the NH is right on the eps apart from the Euro heights which are proving painful - again! 

Its getting frustrating now Blue.We just cannot shake off that euro high! 

[northwestsnow]

I mentioned last night blue despite the wow factor of the ext eps it didnt mean a jot as far as i was concerned until we saw something more like this in the ops.

Lo and behold the ext eps have moved away from the cold scenario this morning.

[knocker]

20 minutes ago, mulzy said:

Bad news folks - it seems that the extended eps have flipped to what looks like a positive NAO.  Nowhere near as good as last night's set.  Let's see if this repeats itself tonight.

Yes I was just about to comment on this although of course 'bad news' is quite subjective. A refreshed Canadian vortex with a trough over North West North America, which, along with the strong Aleutian ridge plunges an Arctic airmass over the aforementioned area. Downstream another trough in the western Atlantic and a flat zonal flow across the Atlantic with negative anomalies and temps a little below average over the UK. All pretty mundane really.

Edited December 28, 2016 by knocker

[feb1991blizzard]

8 minutes ago, northwestsnow said:

Well i will probably be in the minority here but i would prefer Gfs over Euro this morning.Gfs brings cold zonality as the jet heads south and we lose those awful euro heights.

Id actually take either of the ops and the GEFS looked decent as well but now the EPS have backtracked from yesterday's stunning suite.

[Captain Shortwave]

It's never really a Euro high after this current settled spell ends (albeit briefly), the ridge is situated along the meridian (Iberia pushing NNW into the Atlantic).

      

Low heights still over Scandinavia stretching down into parts of eastern and central/southern Europe.

Frustrating is one word for the longer term prospects, at day 6 the Euro at least present a pattern where there is a good chance the ridge near the UK could retrograde given low heights over the Azores (This could engage cold air coming out of American). Alas western parts of the US get a cold spell with a ridge up the eastern seaboard and a slack mess over the Atlantic sector, the ECM op shows promise at day 10 (Again!), oh how we could just see a quick route to a cold spell, still we are in a more promising position going forward a one day (2nd of January) where snow could fall to low levels just about anywhere. It is a start.

[bluearmy]

12 minutes ago, mulzy said:

Bad news folks - it seems that the extended eps have flipped to what looks like a positive NAO.  Nowhere near as good as last night's set.  Let's see if this repeats itself tonight.

sadly the only route after last night was downhill!

btw, note the extension of the upper trough sw this weekend now showing up as per the spread 

and yes, the less said about the extended eps the better, especially given the last suite. maybe headed towards slider territory if we could build a wedge. 

[northwestsnow]

To be fair, while the ext eps are a reasonable tool they are of course liable to swing/flip so from my perspective im not overly concerned with them this morning.That said it feels like whenever they go less cold that will be the winner..

[Norrona2015]

The latest models downgrade is also reflected in the various forecasts this morning. Still the chance of wintry showers for NE Scotland.

[jvenge]

2 minutes ago, northwestsnow said:

To be fair, while the ext eps are a reasonable tool they are of course liable to swing/flip so from my perspective im not overly concerned with them this morning.That said it feels like whenever they go less cold that will be the winner..

Could well be.

Current ECMWF Mean showing the UK having a short colder spell, before drifting all into nearer average or slightly below temperatures. Now, I'm really not going to take anything shown after day 10 seriously, as you can see the signal is lost quickly around that time and the mean looks fairly worthless in the extended range.

Worth pointing out that after the December weather, even average at this time of year can be interesting for some.

[Weathizard]

Well the GFS 0z ensembles are much better than yesterday's 12z meanwhile the ECM ens have now gone the other way!

Typical! That being said I feel the operationals are better with short term upgrades and there's no point looking past that, one of the most irritating things on this forum is when there's a run that massively 'upgrades' caution is urged and it's taken with a pinch of salt yet when things take a turn for the worst things are taken as gospel! Rant over, not aimed at anyone by the way just a general annoyance 

Edited December 28, 2016 by Weathizard

[Gibby]

In my reports and forecasts to my local folk on my Kilmersdon Weather Facebook page I only use the ECM for my forecasts and since I started using it since it's upgrade I have found it very accurate including the controversial mean chart folks here diss. Discounting GFS and to some degree UKMO to some degree is a dangerous game for forecasting I know but I havent found ECM to have let me down as yet. I don't buy into this cold period other than for the first few days of 2017 as ECM for some runs now have kept heights too high to the South with the form horse increasingly preferring a return to milder Atlantic Westerlies and some rain alternating with colder polar maritime NW'lies. I know many of you don't like the mean chart but I do and this mornings offering is very poor if it's cold snowy weather your looking for and lo and behold it is largely borne out by the ensembles.

 

Edited December 28, 2016 by Gibby

[stewfox]

4 minutes ago, Weathizard said:

Well the GFS 0z ensembles are much better than yesterday's 12z meanwhile the ECM ens have now gone the other way!

Typical! That being said I feel the operationals are better with short term upgrades and there's no point looking past that, one of the most irritating things on this forum is when there's a run that massively 'upgrades' caution is urged and it's taken with a pinch of salt yet when things take a turn for the worst things are taken as gospel! Rant over, not aimed at anyone by the way just a general annoyance 

SM post just 4hrs ago paints a different picture. 

Anyway in the reliable we have -10c 850s over large parts of uk 2/1. Will worry about T240 when its no longer FI

 

[KTtom]

You got there before me weathizard....reading the posts this morning it sounds like this is the day the models nail the rest of Winter?!. Personally, never taken too much note of the ensembles,  some of the synoptics shown are close on impossible. Anyway, more twists and turns and no doubt come 12z tonight well all be raising our glasses saluting the gfs for finally nailing down the easterly at + 324.

[Captain Shortwave]

Heh the GFS parallel has read Steve's mind this morning on the 00z output.

         

So the first shot of cold, then a brief less cold period and then a reload of cold from the north east though again the GFS does try to push westerlies through after day 8 though there are some interesting consequences.

[IDO]

2 minutes ago, Gibby said:

In my reports and forecasts to my local folk on my Kilmersdon Weather Facebook page I only use the ECM for my forecasts and since I started using it since it's upgrade I have found it very accurate including the controversial mean chart folks here diss. 

I think we value the D8-10 ECM mean charts quite highly, its the ops we are wary of in these setups. At that range it is proven the mean is far better a guide than the respective ops for nailing the long wave pattern, and of course historically the ECM is number 1. 

I have to agree that PM zonal looks the form horse after D10. No access to EPS but only one GEFS has a HLB at D16 in our region and that is a weak cell. The spike in FI "potential" charts have downgraded in the last few days, but as the D16 uppers mean show, remaining on the cool side of seasonal, and from Jan 1 to the 13th the SE remains with mean uppers below 0c throughout, rare indeed:

D16 

[TheGFStroll]

Hey everyone this is my first post ever... been following this forum for a couple of years now! 

My personal opinion on this cold coming up is get it in first on the models, and then worry about the snow and stuff.... no point worrying about 10 days time when you haven't even got the cold in yet! 

[chris55]

Looks to be lots of options on the table this morning regarding details of the initial push of cold on Sunday/Monday and then what may transpire afterwards. 

Im liking GEM for that little channel low and ECM day 10 looks very nice with a good negative tilt that should allow for a sustained block.

No major confidence in where we go after the initial cold push but will be following things with interest .

GEM

 

ECM day 10