Nevertheless the AO was still negative in January and neutral in February; I thought the OPI simply predicts the likelyhood of a negative AO. I can well believe the AO could be negative this year, but that is not what concerns me.

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You don't remember the St Jude's Storm right at the tail end of last October? But, once we got over that, even though it doesn't seem like it, most of the following November was actually a mostly settled high-pressure orientated month, even though it doesn't seem like it. I remember taking a couple of weeks break from my Cloud Master forecasting duty while "the weather was being boring" at around the middle part of that November and by the time I got back into the routine by the beginning of December, that's when it was all starting to kick off and . . . well, I don't think I've ever been the same since then.
  This November is starting to have a more "traditional" look about it - exactly how Autumn should be in my books. Of course, if it does stay like this in December, January, February and March with hardly any real wintry incursions - THEN, we'll have cause for grumblings.

At the end of the day, the proof will always be in the pudding.

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1993 for me anyday

 

Only just got online today. Looking back at the 00z output, I'm struck by how the current GFS model produced the most dire output from a cold perspective, with the high heights in the Arctic giving away to PV organisation, while the GFS parallel produced one of the most promising sets of charts.

The GFS 06z op then brought back a split PV with some blocking, but that's nothing compared to what the GFS parallel 06z op came up with - running through the lower-res is very entertaining as the Arctic high just keeps on coming and the pattern shifts to favour a ridge through Greenland and disrupting Atlantic lows:

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=204&code=0&mode=0&runpara=1&carte=1 

That's the best of the morning output, with ECM showing a different arrangement of the blocking highs that looks like a longer road to any cold reaching the UK.

 

The divergence between the current and upcoming GFS (I'll refer to them as GFS and GFSP from now on) occurs at day 5, when GFS has LP north of Svalbard keeping a ridge form building to the pole from the western U.S., whereas GFSP does not.

This remains true on the 12z runs now rolling out, though GFS does have the LP a tad weaker and the ridge stronger, so perhaps its slowly catching up with GFSP... assuming the parallel is on the money, that is!

The UKMO 12z op run has even weaker LP north of Svalbard than GFSP does for day 5, and this is also true relative to the UKMO 00z run, so there could be a more promising day 6 chart to come from the UKMO 12z than was seen on the 00z - though it wasn't too bad I suppose, not as dreary as what the past two GFS runs came up with.

 

The GFSP 12z op is now out to day 6, and looks like the ECM 00z, but with slightly stronger high pressure across the Arctic - encouraging signs from that model in terms of the polar profile development.

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The OPI measures the set-up in October. It happens that it's been found to correlate well with the Arctic Oscillation in Dec, Jan and Feb, but in itself it's just a measure of the degree and angle of anomalous pressure over the Arctic in October.

So, forgetting the mooted uses of the OPI for winter forecasting, in itself a highly negative figure this year tells you that the atmosphere over the Arctic this autumn is very different from the way it was last autumn.

I'd like to look at the Meteociel archive charts from Nov. 2013 to check this, but for some reason I can't get the charts from that month to load.

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I wonder who will be brave enough to say about long range forecasts "We don't really know what will happen" 

Thank you James

thats what Id posted earlier to Q but struggle to explain but his got his self down again.

Well for a start the parallel is the only model offering any hope at all. I'd really only be getting interested right at the end of that run at 384h and even then it could go either way. The GFS/ECM have consistently said no, the GEM is even worse. Anyway the 12Z parallel is most definately the status quo. 

 

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I suspect half the fun is trying to guess based to various methodology but my problem would be that the speculation becomes a reason for emotive interpretation. The data being used is a forecast so effectively people are making a forecast interpretation on forecast data and whilst thats fine theres no need to be getting down about it, especially as its nearly 4 weeks to winter still

Ian is correct about November last year......it was relatively quiet IIRC, as was early December.

Q - Relax my friend  

The GFS 12Z has a very strong Azors high in it. 

And the polar vortex is in that nightmare position of the Baffin bay. This chart would have a Strongly positive NAO and strongly negative AO which is actually quite an achievement. 

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What could possibly go wrong? Unfortunately even a small chunk of polar vortex over canada can ruin everything and turn a north Atlantic high into an Azores high. 

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That gm would be concerning  but also very intresting

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=192&mode=0&carte=1

 

Typically, the GFSP 12z op run has shifted towards the GFS 06z op run, with the high pressure in the Arctic toned down a fair bit.

On the other hand, the GFS 12z op run sustains an Arctic high throughout, and sticks with the split PV shown on the 06z. This is also more in line with the ECM 00z, though with the PV split less pronounced in the 8-10 day range.

 

Overall, then, the long route to any significant cold reaching the UK is favoured, just like it has been for some time now, though it does look like we might be waiting a bit longer than yesterdays runs were suggesting.

It will depend on how the strat warming impacts the troposphere at that time. Having that 'weapon' in our arsenal places this year a long way from last year.

 

The silly season sure has got going in a hurry this year. I feel like focusing on the shorter term again for a bit - good for the sanity levels 

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I usually do - There is plenty of "weather" coming up. If you like rainfall and maritime convective thunder then you're probably going to be happy

 

http://www.wetterzentrale.de/pics/Rgem1921.gif 

As posted by Polar Low above, a very stormy GEM 12z, but luckily too far out to get too concerned about just yet, although I think the GFS parallel had similar yesterday.

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It might have already been posted on here, but the new GFS parallel 3D charts are stunning...

http://www.meteociel.fr/modeles/gfse_3d.php?mode=0&lat=60.62&lon=3.48&ech=60&zoom=5.25 

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">http://www.meteociel.fr/modeles/gfse_3d.php?mode=0&lat=60.62&lon=3.48&ech=60&zoom=5.25