The GEM in particular could become very cold very quickly. 

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Back to the eighties style battle. dec 1981 please!!! just a few more times for me in ,my life time

http://www.meteociel.fr/modeles/gefs_cartes.php?code=16&ech=252&mode=0&carte=1

  

dear me  many would be in melt down it seems be a long time ago now.

Becoming much colder soon heavy snow snow showers along the east coast soon more general snow later.

 

Very interesting modelling. Comparing today with the forecast for day 10 reveals a vortex that is in decline. This is clearly the opposite of what we should be seeing. The thing about the repeated firing of WAA into the polar field via the meridianal pattern is that it generates further wave breaking into the stratosphere which will weaken the vortex further (or at least prevent it making the headway it would usually do in November). It almost becomes self perpetuating until something stronger comes along (eg big increase in solar activity ).

At the moment, we see the abnormal cold being displaced into the mid latitudes heading for the states. If we are looking for cold, we must hope that the usual sinking south of the colder air that would occur in November happens in tandem with a slightly different position of the arctic blocking. It's feasible that the upcoming drive of the jet towards Iberia generates a block to our north which could then advect cold west from Russia via lowering heights to our south. At the moment, the high heights of the sceuro block mean this cannot happen. we are going to have to be patient as the current pattern does it's stuff and sets us up for a possible cold start to winter. Of course, we could see the vortex recovering temporarily and bringing a westerly phase through nw Europe before the wave breaking from the first half of November eventually brings that to an end. Very exciting if you are a coldie and very different to a year ago.

 

Excellent analysis of the situation Nick, I'm always glad to find a post of yours here 

I've only had time to glance at the models today but it seems the overall theme hasn't changed much in the past 24 hours, with the output simply exploring variations on said theme, though perhaps a little more emphasis on the PV trying to set up shop over Siberia - but only as a relatively weak feature.

The warm air advection northward through the likes of Scandinavia looks to be about as strong as could possibly be achieved, and gives the charts a bit of a mid-Spring look to them - it's weird seeing southerly tracking lows interacting with warm pools to the east of the UK in mid-November as occurs on the ECM 12z op run.

To think, had the Atlantic trough set up further west, we could have been shattering the date and month records for high temperatures during the first few days of this month.

Having read the Cohen papers on the subject of the WAA leading to wave breaking in the stratosphere, I can see where the excitement is coming from, and I'll admit to feeling a bit of a buzz even this early, despite the barricade of skepticism that has grown between me and exciting longer-range weather prospects over the years - an inevitable consequence of examining the British weather so closely 

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Some interesting synoptic patterns this morning and while not supporting deep cold and snow at the moment some building blocks are beginning to take shape but will it hold firm for Winter 2014-15. My daily thoughts can be found below.

http://www.norton-radstockweather.co.uk/NEW-Model-Analysis(2859336).htm

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This is a great summary about the current set up. And maybe the very first sign in the ECM ensembles the Control goes cold at the end.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php

 

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New day, same theme and variants of.

GFS nearly takes the fast route, with the main areas of low heights in the Arctic located in Canada and Siberia by day 8, far enough apart to allow a strong ridge across Greenland. The Canadian trough then topples it before it can really deliver.

ECM doesn't shift LP from Svalbard to Siberia as quickly as GFS, which prevents the strong Greenland ridge scenario. Instead LP to the south of the UK dominates the scene and conditions could be exceptionally mild days 8-10.

 

There's still a lot of high heights being projected in the Arctic by both models, with the PV about as broken up and disorganised as I can ever recall seeing it at this time of year - though I'll need to check the archives to know if that's truly the case.

I have often been struck by reports of exceptional warmth preceding some of the most impressive cold winters. The current output does a good job of illustrating how the the jet tracking well south of normal, coupled with unusually weak westerly momentum (a blocked pattern), can simultaneously bring NW Europe and the UK mild conditions and develop a polar profile conducive to cold outbreaks a number of weeks down the line.

Really the bigger uncertainty now is where the cold outbreaks end up going. The UK is notorious for being on a knife edge 

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Something that hasn't been mentioned on here much is the remnants of super typhoon Nuri look set to get caught up around the Aleutians, the warm air is set to cause some explosive cyclogenesis with ECM and GFS hinting that pressure around this area could drop exceptionally low to around 915-920mb which would beat a record set in 1977.

I don't think the implications of this have been fully picked up on by the models yet but it's fair to say this will cause a big ripple in the NH jet. There are signs the Eastern USA could be in for a notable cold blast for mid November as a result. The impact of Nuri will lead to a meridional jet stream pattern, whether the UK will be on the right or wrong side of this remains to be seen.

Interesting nontheless though.

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GEFS and ECM ens starting to trend colder right at the end of the run, everything falling into place nicely as things high up looking promising as well.

 

 

In fact the foundations a being built earlier in the runs, we have to build up a cold pool though, a stonking big greeny block smashing clean through the polar regions on some of them!!!

Teases & taunts from the weather gods!

Love the posts that look deeper into the teleconnections & wider drivers of the weather. Top stuff, guys

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Still very difficult to see cold arriving before the last third of this month. GEFS to the north don't look very interesting. To the east a few cold outliers are now appearing but a lot of hoops need jumping through before that reflects in a cold snap in the UK. GEFS6z for Moscow illustrates well:

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I was discussing the overall pattern elsewhere last night in respect of the local synoptics encouraging a general trough close to the UK under a meridional pattern, with HP to the east so its no surprise that Moscow is cooling, being on the other side of or underneath the blocking High

I don't think anyone is looking for cold until past mid month Brian and even then it maybe delayed. These sort of set ups are slow burners with the Stratosphere taking mini hits of wave 1 and 2 activity  thus keeping it from becoming more organised. The NH looks primed for a cold outbreaks at mid latitudes sometime over the coming weeks, the only concern being will it all be too far West for us here in Blighty.

I recall reading somewhere that one reason for the winter of 62-63 was persistent low pressure in the Aleutians, combined with a negative AO pushing Artic High pressure this way leading to a negative NAO and blocking over NW Europe. Perhaps someone more weather literate than me could confirm or reject that thesis.

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Hi all,

Here's today's video update:

Unusual November Patterns + Final Update From Huug Van Den Doul

http://www.gavsweathervids.com

Some interesting synoptics next week, but no sign of anything cold (after today and tomorrow anyway) for the time being.

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GFS12z twitching this afternoon. 

 

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I seem to recall something similar, although it would be just as true to say "one reason for the persistent low pressure of the Aleutians was the record-breaking cold and blocking over NW Europe"....

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Growing consensus for a sliding LP from Monday or Tuesday onwards next week, with the eastward progression of the system halted by an immense blocking high across Europe and Asia.

The orientation of that blocking looks to bring a flow of relatively warm, moist air into the mix across the UK, where interaction with the low pressure and associated frontal systems looks likely to produce large amounts of precipitation. There's then the issue of those frontal boundaries being slow moving or stalled, which could produce some exceptionally large totals in places - here's the totals to the start of Monday on the left (most of it falling from 00:00 Friday onward) and the totals to 13:00 Wednesday on the right (end of higher-res):

That's quite a jump in the space of 48 hours, especially given how much of the convective precipitation GFS tends to miss (at the 5-8 day range I usually add 10 mm to very loosely compensate).

While this is happening, high pressure in the Arctic looks like it will have a go at setting up over Greenland. GFS is still showing a toppling ridge scenario, albeit a slower one as the Atlantic flow is a little more amplified - it almost manages to pull some cold air down through the UK:

...but the ridge just doesn't hold on long enough against that deep trough between Canada and Greenland.

GEM prefers to have some fun and games:

...but this actually serves to show how unfavourable the pattern looks to be for getting a cold outbreak to the UK within the next 10 days. Instead this is if anything a wetter scenario than GFS goes for, as the LP by the UK finds itself well and truly stuck just west of Ireland - in a prime position to drive convective showers inland in a moist environment, while continuing to deliver more persistent rain wherever the main frontal boundary lies - though it could be mixed out by this time, leaving only fragmented precipitation. Not that such details are worth worrying about at this range!

 

The main message regarding the longer range that I've picked up from reading around is that our best bet this side of 2015 is the knock-on effects of the patterns being shown for 8-10 days time; impacts on the stratosphere may feed back down to the troposphere as a period of high latitude blocking that, with any luck, will be better orientated for driving cold to and across the UK than what we're looking at this first time around.

My main concerns in the meantime are high rainfall totals Thursday-Friday, possibly Saturday-Sunday (not certain), and then through much or all of next week. Familiar territory!

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Great analysis people. Although I am loathed to mention it, the CFS has switched these past few days to repeatedly showing some fairly blocked scenarios days 15 to 20 - set-ups that could well release an early beast.
There now, I've said it

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Cheers Gav

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It looks like the models are suggesting we may get a cold spell around the 20th. Definite height rises in useful places by ECM240. The GFS is going for something similar.

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Relatively mild and potentially very wet rules the roost for the foreseeable. Twitchy bum time again for flood-prone areas. 

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not if you look at this Q that does worry me how that get pulled over towards Canada.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0&runpara=1&carte=1

 

Even that could end up pretty favorable if there is some communication between the scandi and arctic high. I think is touch and go tbh. I'd say there is the potential for a gradual transition to something very cold in the 2nd half of the month, although this will go through a southern blocking phase which could actually be quite mild by day. Whether it comes off or not is up in the air as always, weve seen patterns at 96hr go to the dogs before. I just think the 2nd half of the month looks more favorable whereas the firs half is a complete write off. Although I must admit, I don't seem to have the overwhelming desire for snow at the moment; I'm actually quite enjoying the (relatively) mild weather. 

 

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