Cheshire Freeze

That +NAO though... My only concern at present is that we've seen strong Siberian highs over the past few years but they have done little to disrupt the NH vortex enough so to slow down the Atlantic conveyor on our side. Remember all that WAA pumped relentlessly into the Arctic early Jan? Well even that wasn't enough. I'd personally much rather see the trop vortex over that side and a more blocked look to proceedings over the N Atlantic sector. ECM holds more promise at day 9 but we have all seen the tendency for over amplification/blockiness in its latter output Day 10- Ideally we don't want to see the trop vortex hang around Greenland for too long as it will just serve to strengthen the jet across the N Atlantic and suppress any attempts at heights building to a useful latitude going forward. Hard to get out of that pattern as we all know.

Also before people start saying 'but it was showing mild yesterday', there is a difference between the daily runs on meteociel and the averaged anomalies found on the NOAA site. The averaged anomalies take a number of day's runs and average them out I think.

Just seen this on latest CFSv2 daily run...need your sunglasses to view that anomaly

Don't fall into the trap of seeing pink colours and thinking 'oh, snow'. We see this time and again from the EURO4. If we look at the corresponding precipitation for 6AM there is barely any over most of central and west Mids at that time Places like the Lincs Wolds and southern and eastern peaks may do OK for a few cm though.

Hmm I'm not convinced What I get from this is a few CMs over higher ground

Risk seems to have diminished somewhat on latest Euro4 output http://expert-images.weatheronline.co.uk/daten/proficharts/en/euro4/2016/11/07/basis12/ukuk/prty/16110900_0712.gif

Hang on a minute, interesting developments on the 0z GFS. Small patch of high pressure shows up S Scandi which holds up eastwards progression of LP. Very wet UK but jet buckled and sending WAA northwards Intriguing watching the trop vortex trying to crank up then afflicting itself as it does so. Attacked from all angles and starts to become ragged again AO firmly negative on the 0z by day 10. It's like the parting of the red sea across the polar regions between days 8-10. Run the animation through on Meteociel. And sure enough, up she goes in the Atlantic Come to papa! Best FI output so far this season by a country mile.

I said this last night and looking at that chart it still applies I can't help but think that or the time being we may have to suck it up and put up with an abundance of more mid latitude type blocking with the Azores high loitering with intent close to our W/SW in preparation for a more favourable upstream pattern. What I'm seeing in the output at the moment is attempted ridging N in the Atlantic before a flattening of the pattern once again.

Aye, more than a whiff of 2009 about upcoming synoptics...namely Atlantic depressions meeting a block to our east and thus becoming slower moving around UK shores. Can only hope it starts to mirror 2009 when it really matters i.e into December!

Yep, and the depth of its forecast +NAO is worrying. Would be a mild old 3 month period should it come to fruition. I hope very much that it doesn't! On to the 18z GFS...you can clearly see that shortwave feature which interrupts the Azores-Scandi link up...

It's a concern that some of the long range models are starting to drop like flies after a very promising update last month with them. CFS has flipped pretty majorly to a massive +NAO with all 3 winter months looking above average. What we don't want to see is the GLOSEA update and EC seasonal flip to reflect this....Once the seasonal models get into agreement over +NAO winter conditions they very very rarely back away from it and it usually ends up being the scenario that plays out. CFS monthly means are here http://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/glbz700e3Mon.html

I'm not so sure. These height rises out to our E/NE are often red herrings. They also would not (in the mid term) fit with the notion of a trop vortex transporting across to the Siberian side of the hemisphere. I can't help but think that or the time being we may have to suck it up and put up with an abundance of more mid latitude type blocking with the Azores high loitering with intent close to our W/SW in preparation for a more favourable upstream pattern. What I'm seeing in the output at the moment is attempted ridging N in the Atlantic before a flattening of the pattern once again. What I will say however is that it is a good sign the tendency is there for these blocking features to want to try to take up residency further N than what could usually be anticipated at this time of year. Makes me think it's only a matter of time until it all clicks...perhaps.

From what I can see, most of the extended NWP is now converging on the same scenario for just after mid month. The last few GFS runs have produced near identical finales.

Is that the CFS? Broad general agreement with GLOSEA5 then. A potentially very cold pattern showing there. I think back end of 12z GFS shows how the actual synoptics may look from what the anomaly charts are showing.

It should be but I'm not sure it can be given what we see with the temperature anomaly plots with these models.

I think it all depends on which historical mean they're using to base the temperature anomalies on.

Historically, until the 1960s I think, they tended to be quite severe. Then this flipped...with 2008 possibly being another flip point and reverting to the pre 1960s patterns. I guess this year will be a good bell weather to test this theory out.

It'd be interesting to see the pressure anomaly charts in a week or so for the autumn to date. I suspect that we're bang on the historical analogue for a post strong Nino into la Nina autumn. This is interesting because the corresponding winter pattern is anomalous Greenland-Iceland heights and a resultant cold UK.

I think the groundwork has already been done for the early winter pattern (at least). As I said, I don't think I've seen an archive chart yet where November didn't feature a strengthening trop vortex and at least some mobility.

Totally correct, John.

Yep, no signal for an early season vortex residing Greenland/Canada (well not currently anyway) which should maintain the risk of N Atlantic/Greenland heights as we head through latter November and into the early winter period. We see attempted vortex intensification over the next week or so around the above mentioned areas but with the tendency for quite rapid displacement towards the Siberian side, we are going to see the NWP fiddle about with some Atlantic mobility as a response to this signal. I suspect mid November's weather will not be entirely clear for another week or so.

We were always going to see a period of more mobile weather at some point this coming month though. We were never going to sail into winter being blocked all the way through. I don't think I've seen one archive run of any year where this was the case. Personally I don't want to see any attempts at deep cold until we're about to enter December. As long as we don't see an entrenched PV setting up to our N and NW then I'm happy. The strat profile is also light years away from last year's offering.

The general gist of what I've seen in today's modelling is a slight relaxation in the very blocked Arctic profile days 7-10 before renewed tanking of the AO possible days 10-14. This ebb and flow is to be expected (given the battle for vortex intensification being repeatedly offset by minor stratospheric warming episodes which will not allow the vortex to settle for any protracted length of time). There also looks to be a hint in the 12z GFS of another wave breaking attempt post day 10/11 (as pointed out by Feb1991). All in all a lot to keep tabs on in the coming weeks.

Yep, I noticed this. Keep 'em coming I say. Get another major episode and we could see a very interesting back end of November into December.

Once again a very weak and disorganised tropospheric vortex showing as we head towards mid November. What is interesting too is that small warmings in the strat seemingly continue throughout the model run after brief lulls. Unlike last year where they were shown to skirt around the strong PV core, these warmings seem to be headed more direct and are having the effect of not allowing the vortex to settle or regroup easily.