The day that a GFS Northerly verifies will be the day that the sun rises in the west

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By and large, GFS is achieving what it does via a trough/ridge development over N America and Canada (Rossby Wave development), which is able to have more of an impact than would usually be the case thanks to the disorganised polar vortex.

Aloft in the stratosphere, the vortex is actually looking to gather strength quite steadily over the coming fortnight, suggesting that the polar vortex should gather itself together by early December.

 

I have seen suggestions that GFS has a bias for overdoing Rossby Wave development over N. America, and can recall some wild ventures along similar lines later last winter, so I am suspicious of the recent colder runs in lower-res.

Given the ahead-of-schedule El Nino atmospheric state that appears to be at play at the moment, favouring what we'd usually see in Dec-Jan but a month earlier than usual, the ECM 00z op run is a much better fit days 8-10 and going forward from there, with a trough developing west of the Azores, displacing the so-named High into Europe, while cold air is restricted to parts of Scandinavia.

 

 

With long-range model output strongly reflecting this El Nino atmosphere theory, it's no wonder that the above looks very similar to GloSea5's ensemble mean projection for Dec-Feb. I've also posted the Jan-Mar mean to serve as a reminder that hope it not lost should we see the Euro High feature a lot in the next couple of months:

 - though I must admit, I'm not a fan of waiting until the back-end of winter for cold and snow, but what can you do eh? Never mind though - I'm fairly sure we'll have far better opportunities for that within the next few winters.

It will be interesting to see what the November GloSea5 update looks like when it's uploaded within the next week or so.

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The 0z ECM control delivers a northerly at 282 as high pressure builds to the NW. The high then slowly sinks over the UK and moves SE'wards. Not very exciting, but more seasonal conditions at least!

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The 12h GEFS shows colder scenarios in a slight majority at 300h.

Simon Keeling (very LOUD)
https://www.youtube.com/watch?v=v_aljs1xYg4

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That looks quite likely as it is so mild now and the weather normally evens up  over time. Not sure how cold he means  but definitely a lot cooler.

Simon's output is always a good read, but on WX he does tend to side with GFS too much IMO and I'd like to see more of a blend of output being used in his discussions.
No problem with this particular summary as it is exactly what the Chinese model is saying.

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FI looks much better this time, lower pressure over the med, higher pressure over greenland. all good things.

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The temperatures at the moment and in the coming days (based on GFS) are just bonkers;

Today's mean is 5.5*C above the long term average for 5th November (2000-2014 using my own data).

Tomorrow's anomaly looks to be around +4.8*C, and following an overnight low of 14*C or so and with a daytime high of 15-16*C, Saturday could achieve a staggering +7*C anomaly. Only 1st July has achieved a greater anomaly this year and that was an exceptional event.

Sunday may exceed a +5*C anomaly. Monday could be a bit tamer at around +4*C but Tuesday could see similar temps to Saturday which would bring about an anomaly close to +7.5*C as the LTA for the 10th is almost half a degree lower than for the 7th.

 

Combined with temps averaging 3.0*C above the LTA for 1st-4th November, the anomaly for the first 10 days, IF the recent GFS runs (i.e. those of the past 24 hours) are close to the mark, could be around +4.5*C. I'm fairly sure I've never recorded a positive deviation that large for a 10 day period, in fact probably not much beyond +3.0*C in the last decade of obs.

With this in mind, the way ECM shapes things up days 8-10, and how consistent that is with the 00z, leaves one wondering just how high the monthly mean could be. After all my local mean could be not far off 13.0*C to the 10th and the CET zone is rarely more than half a degree below that in my experience...!

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Indeed, I would not be surprised if some places away from southern england are now having warmer days than they did for most of the Summer! No real (supported) sign of any cold weather in the second half of the month so could well end up a very warm CET for November, how long will the euro slug last?

The ECM-32 control run shows generally mild, westerly or SW'ly conditions for most of its run, albeit with a couple of highs moving swiftly SE'wards over the UK to "top up" the European high later in the run. This would at least bring a more seasonal feel to the final third of the month.

The ECM (15-day) 12z control run shows a weak ridge crossing the UK around 240, followed by more mild SW'lies as again it just "tops-up" the Euro high. By 360 there are westerlies with perhaps a chance of a NW'ly flow thereafter.

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This morning's ECM is a little different but the general picture from the NWP remains the same and I agree with your comments about the potential temperature anomalies this month. It could make up for the rest of the year's averageness! 

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But, surely, on average every year will have one significant anomaly - so if we weren't having this anomaly it wouldn't have been an average year anyway

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True. The averageness of this year to date is, by itself, anomalous. At this stage of the month, given the variety of outputs, it is very premature to be painting a picture of the overall month, and IMO to do so is not to have learned lessons from the past.

Yes, the first third of the month, indeed probably the first half, looks remarkably warmer than average. Beyond that anything is possible from exceptionally mild conditions continuing to cold wintry weather from the north. I have seen n evidence to suggest we have the skills and technology to accurately predict which based on current output and past attempts. At best we can talk about probabilities and percentages but in the end the can always be presented and adjusted in some way to tweak the argument to the proponents viewpoint.

In short a very "warm" start to the month, beyond then let's watch and see.

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Mild or very mild for the next 7-10 days then a brief cold NW'ly, followed by a potentially brief frosty ridge of high pressure would be my prediction this morning. Frost is a novelty down here these days so something a little more seasonal will be welcome. 

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GEFS 0h ensembles continue to serve up a 50:50 split between cold and mild options at 300h.

Here are the 850s. How do you define cold and mild when you do these splits?

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Unsurprisingly GFS extended melts into mix of options more or less showing a mobile westerly theme. Will this moderate the hype-casting that goes on in this thread at this time of year? No of course it won't lol.

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Yes it does Brian is this the first big move for ecm 12z mean at around day 10 I look daily and its the first move of its mean you can see the general trend also in a number of the gfs members.

ECMWF/GFS DAY 8-10 MEAN 500MB HEIGHT COMPARISON

 

 

 

Panel view gfs members

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=252

 

Having said that ecm 0z mean does not like it at all perhaps its members are slower to a "possable" change at that time scale so as always more runs needed we have to get rid of pressure to the south

 

 

I'm not seeing much hype-casting on this channel. Most people here seem to expecting a mild or very mild winter with a chance of cold snaps towards the end?

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More so when you've got the GLOSEA5 model giving strong signals for a mild mobile westerly start to winter with a possible switch to colder conditions in the final third. Personally I think we'll see a milder than average winter throughout with odd cold snap thrown in for good measure, the atmospheric response is typical of a strong Nino going forward from this point with a strong Euro height anomaly and mobile W/SW regime for the UK.

Not sure about averageness, down here for sunshine I suspect we are way behind average. There has not been a single day in the last 2-3 weeks that the sun has come out for more than 15 minutes before going back behind the uniform grey.

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I like to expect the un-expected, TBH, I take no notice of long range forecasts, as long as they are JFF which should be that way, just like GAVIN does on his long range update musing thought all JFF

as for this mildness it can not go on forever something has to give,

Sigh - that Euro High is going to spoil this winter again isnt it.

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Channel low on the GFS6z gives heavy snow in the south. 

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