Don't get me wrong - I'm not saying that the orientation and behaviour of that low hitting the sweet spot equates to a nailed on easterly at T+240, I'm saying that the first hurdle to jump is in that time period. 

True and we also need to remember, as brilliantly highlighted by Retron (Darren), we currently have, well modelled in the reliable timeframe, pulses of warm air advection. These COULD lead to something very 8nteresting, they might not, but they give us a shot........better than milk southwesterly gunk......

Surely, as you rightly point out, other variables come into this and coulD have an impact either way. So to definitively say it will not happen is folly, if you are acknowledging the  potential impact of as yet currently unmodelled events?

Fair enough, we need the WAA to keep pushing north (and the more directly so the better). 

Its fascinating to watch, but sadly the likely result come February 5th, is going to be miss rather than hit - we know this, as this is what happens, time, after time, after time.

Yes - there is no consistency between runs let alone between models and it all remains outside a reliable timeframe. Therefore, it is only vanishingly likely to happen. Less than 10% chance, I would imagine.

GEFS look even worse now, so the ECM op is probably just a freak run

I could be wrong but I think -11 850's as per the ECM 240 chart for my part of the world is the coldest it's shown this winter.

Nice to see the ECM Op going with a colder solution, to back up the colder GFS members.

It's all quite tantalisingly close to something interesting but whilst there's so many more milder/less cold options about, and we need a lot to go right in the near term and into FI, it's just one option from many.

It does seem though that if things go our way it will be coinciding with enough cold air being readily available for a proper shot of cold, rather than a chilly waft.

The 2017/18 roller coaster remains alive and well

Have you actually looked at the 12z GEFS or are you basing that on comments you've read elsewhere? IMO there is plenty of interest.

https://www.theweatheroutlook.com/twodata/gefs.aspx?run=na&lg=850&lglocation=london

No more than the 00z ECM Op was a freak run in terms of 850s for its mild outcome in the latter stages. The 12z ECM Op is colder than the mean 850s in the last couple of days, but not freakishly so.

They look OK to my eyes too, Brian.

Pessimism with regards to FI cold, particularly from the east is, sadly, rarely misplaced but I don't agree with the bolded bit.

The ens have been consistently floating a low but noticeable chance of cold from the East for quite a few days now. The signal's been waxing/waning but it's been there reliably. 

The other thing that's encouraging is the start of the colder air hitting us (on the members which bring cold in) has been creeping in from the depths of FI to somewhere closer to the edge of the reliable.

The ECM ens have also had a small but noticeable colder cluster too from what I've seen others posted, which presumably is what the Op has picked up on this occasion.

Does this mean a cold spell is likely? Nope.

Possible - yep.

Given the persistence of the signal, the fact Feb is traditionally a month where the Atlantic packs less punch etc. I'd probably put it higher than 10%. 20/25%ish at present sounds about right to me, which is of course another way of saying it's 75/80% likely not to happen

It would though be a bit boring from a model watching point of view if instead of looking at the various options presented you just plump with 'not cold' - I can do that without even needing to turn the computer on but it does rather take the fun out of things

Yes, you are completely correct Brian. There is indeed lots of interest in the 12z GEFS even if in the end it comes to nothing. They don’t look “even worse”, if anything the mean seems to be slowly shifting to be a little cooler every day. (Note this is for MBY but I suspect other areas are the same. I just check one location as it is easier to keep tack of).

If he posts then you can guarantee there won't be a cold snap never mind an easterly. Don't really see why people are hopeful of a full blown easterly just because there are a few runs showing one, many day's out in the distant future. 

Incisive as always...Steve has forgotten more about model watching in a day than you'll know in a lifetime.

"Hopeful" describes your opinion on certain posters, and it does not accurately reflect the balanced opinion on model output that is occurring in this thread IMO.

I guess in the same way people are hopeful of a Spanish plume in the summer? Is it not their right to hope for a scenario that is being shown in the model output? For said scenario to be discussed?

Regardless of the chances of such a scenario verifying there is every right for it to be discussed in the Model Output Thread.

Additionally, your reference to Steve Murr is disrespectful in my opinion.

There is plenty of interest for coldies in the output currently, as there has been for much of this winter.

A Spanish plume in the summer is far far more likely then a cold easterly in winter. Sure it' the model output and all model output is fair game, but with the just sniffs of one I can't figure why some repeatedly get the hopes up. 

With regards to Mr Murr it was not my intent to be disrespectful towards him. Over the many years I've been following this forum I can say with honesty personally speaking from memory (which can be foggy) I can't remember seeing a cold spell come off after he posts his very technically loaded posts... it' almost like he's an omen when it comes to cold spell - superstion an all. 

Welll there have been some strange comments here this evening; more akin to superstition than model analysis.

Anyway, the ECM 12z ensembles for London show that the Op wasn't without support for that particular evolution.  From next weekend the Op has taken the colder route instead of a milder one for a change.

Clearly the pattern on 5th could take the milder route but there's a reasonable cluster of colder runs in there.

Whatever and anyhow, I have seen plenty of Cross Model Agreement that we are still seeing Quite Cold weather type Westerly NW And Northerlies are on the cards as from Saturday 27 January 12z GFS, UKMO and ECMWF Models.

Another two cold Low Pressure actually three of you add Monday’s cold WNW flow, these are coming to UK from NW Atlantic, helped in by the slow moving and back building of High Pressure areas that also ridge in to South UK and Central to Eastern USA.

There looks set to be both Low and High Pressure in Greenland And NE Canada as well, With Low Pressure pushing East in Central And NE Canada to join some NE USA to Nova Scotia and Newfound PV Low’s And they are squeezed but that intensified them and from SW of Greenland with North And East Greenland And Iceland to West and NW Norwegian Sea Blocking High’s it means they track SE to cross us in UK and affect much of NW North And Central to NE Europe where some very cold conditions and heavy snow is expected later this upcoming week.

By the Sunday and Monday the UK NW Europe should see some cold Northerly to NE winds, but UK shall as will West France too see a Cold ridge of High Pressure while over NE USA NF and NV as well as SW Greenland S SE Greenland and North to NW Atlantic are expected to see a further cold air advection with two areas of Polar Vortex Low Pressure systems, with light winds cold and frosty weather in UK- Central N Mid N Atlantic West SW of UK High Pressure still hold as a strong block, and a cold High over North NE Europe and another cold High Pressure SE and N NW Norwegian Sea. SE Europe and Central Mid NE Europe cold with snow showers or spells of heavy snow. And Sunday 4th and to Monday 5th Feb. are likely to see cold frigid Low Pressure bringing cold air to South and SE as well as Central Europe.

The North Atlantic Low By then will it is expected push across NW and N UK NE Atlantic and to the NW of Northern NE Europe or be stuck for Tuesday Wednesday over West and NW Norwegian Sea And over North Atlantic, with UK weather maybe affected by cold NW SE tracking Low Pressure with High Pressure from Ventral N Atlantic and to our West And SW, including Central to East USA Western N Atlantic High Pressure Blocking remain strong.

May the cold Low Pressure in Wednesday and Thursday as well as Friday and Saturday bring with it wintry showers and cold nights and evenings and mornings as well as Low night and day minimum and maximums. 

😏🌎⛈🌊😃😆

I have done the math in my head based on 18z ensembles @ +300/+306! Out of the 20 ensembles 4 show an easterly - Thus still remains a 20% chance of a cold easterly developing at or around+240z with a scandi block: - Only showing ensembles with easterlies:

Still this could bring some wintry flurries to the east coastal areas and the far south for a time with daytime maxes of +3c. The bad news with this is that there is no Greenland HP block or to the north.

20% chance of An easterly (4 ensembles showing this, as seen above)

10% chance of northerly (2 ensembles)

30% chance of a north westerly (6 ensembles)

10% chance of a southerly (2 ensembles)

10% chance of a south easterly (2 ensembles)

20% chance of a Flat westerly or south westerly. (4 ensembles)

------------------------------------

Quite a mixture but at the moment brief cooler/chillier north westerlies and maybe northerlies (like we have been seeing so far) look more likely with 'sliders' than an easterly. But the positioning of the HP is crucial. It's interesting as some ensembles look either quite mild and dry or quite cold, where as some look stormy like P19 and P20. But then again this brings down colder air after or on it's back edge as fronts move south eastwards to pull down colder NE'ly winds for a time.

Still so much scatter and so many different ensembles that show different weather set ups and patterns etc - Anything could happen and even now it's the 28th Jan and we still don't know how the first week of Feb will go!? I am bit disappointed to see some ensembles showing such unsettled wet and windy weather still! As if we haven't had enough wind and rain!? They are a minority but still.

Most of the zonal LP systems are toppling over the mid Atlantic ridge instead of coming straight up for the Azores ! What we really need is that Mid Atlantic ridge to track northwards - it seems a little stubborn! Also it really doesn't help when we are forecast to continue to have a +NAO. Shame it's never gone negative at all this winter. At least the zonal winds will weaken within the next few weeks. Fingers crossed for a SW or SSW.

Tomorrow the runs could well flip back to zonal but I am still trying to keep hopeful and positive for some cold weather and snow this winter. 

Once again the GFS op goes off on one, earlier than before... A sub 925 low at 204 is most unlikely to verify and that'd imply the modelling of the strength of the jet is overblown with all the attendant knock-on effects.

The ensembles will of course be interesting later this morning. It's worth mentioning that EPS yesterday had an over 50% chance of an easterly to our immediate east by day 9, with around a 30% chance of a prolonged easterly.

EDIT: As expected, at the same time in the ensembles none of the members have such a deep low. Either the op is picking up on subtleties that are missed by the coarser resolution of the ensembles, or it's barking up the wrong tree.

SECOND EDIT: And now that they're out in full, a marked downgrade in terms of cold on the past few days. A number of members also inflate Atlantic lows in a rather over-the-top fashion (one goes below 915hPa). The last time this happened the model ended up backtracking as it'd overblown the jet, but of course we can't tell if that's the case this time. Either way, as far as G(E)FS is concerned, the chance of a cold easterly is now a bit lower than it was. Onwards to the ECM!

So you don't think a chunk of PV will be heading for Biscay then? 😆

Things developing pretty much as expected. As you get to within 5-6 days of February 6th, expect a zonal picture with west to east movement.  The GEFS have picked up on this now and are eliminating the easterlies for February 6th, one by one.