beng

Not just the AO, Steve illustrated that with the east based QBO, then the NAO is more likely to follow the AO - I think I saw an 80% chance of a negative NAO - if the OPI is low enough - if you have an east QBO? So unless the QBO suddenly reverses, a strongly negative OPI (if we get that) implies a very good chance of a negative NAO. Of course it is still possible to be mild even with a negative NAO - but that is very unlikely when combined with a negative AO at the same time.

Thank you Riccardo - I've been looking every where for this as I followed it last year, but forgot to bookmark the url.

Does anyone have a link to that Italian blog where they've developed their own October pattern indicator for predicting the winter AO? They'll no doubt be gathering the Oct data before too long and it would be good to keep an eye on that as it's proved quite reliable. edit: found it, http://forum.meteonetwork.it/meteorologia/ Not yet running obviously!

http://www.nottingham.ac.uk/cem/pdf/NR111_FTR_CEM-08-09-08.pdf Have a read of page 28, definitely seems like EU policy is being implemented in the Somerset levels to me, despite some existing legislation getting in the way. I am biased of course as personally I can't stand the EU.

LOL - let's wait until it's t48 before bringing up Feb 91. Right now I'd say only Northern areas are most certain for snowfall. It's a different kind of setup IMO, as right now we don't have the Scandi hook jet modelled (my own terminology! - where you get a loop running up over Scandi, down through Russia and a streak back round through the UK in a loop) - that helps bring the really deep cold from Russia around the high. Instead we have a more powerful SE jet - so it'll be harder to bring in the really deep cold, but it could still result in a lot of snow if we get lucky. Here's the jet pattern from 1991 http://www.meteociel.fr/modeles/archives/archives.php?day=6&month=2&year=1991&hour=0&map=3&mode=0 The further North and East you are, the better if you're looking for snow, but if the very gradual retrogression of the pattern continues, then the snow zone will expand.

One of the things to watch for now over the next 48-72 hours or so (hopefully) is a gradual drop in the project 850 temps for the end of next week. My reasoning is that I'd expect the models to begin to factor increasing European Snow cover causing a cooling feeding back. Right now it looks like we've got Snow over Ukraine, Poland and East Germany - but I think this will increase from around Tuesday next week. http://www.wetterzentrale.de/pics/Reursnow.html

Steve - any chance of you having a stab at the probability of the t144 chart verifying? I'd have expected more energy to head SEwards - based off the t120 chart.

ECM is going more the GEM route IMO (fingers crossed anyway) with more of the energy held back west as the 2 lows phase, with a small amount of energy left to go East and under the block. Don't want to temp fate here, but t144 could be cracking... EDIT LOL t144 is very strange looking - not sure that's likely in reality.

From a IMBY point of view, I have a concern that we'll see the models pick-up on the dreaded short-wave in the Southern North Sea (due to the energy still available there), probably in the next 24 hours. This will initially (at least) probably restrict the deeper cold to more Northern areas, in which case we'll need the blocking to be sustained for a couple of days, before those in the South get to join in the fun (assuming the broad pattern is correct).

If anyone is reading the model outputs and expecting cold zonality then I think they need to be a little bit careful. Past 120 hours the models will not necessarily be picking up short waves that will develop; these shortwaves as they deepen swing North so the best chance of colder style 'zonality' IMO will be in the NW of the British Isles etc. It's been cold down here the last couple of days - didn't reach 3c yesterday in Charlwood, Surrey - although I appreciate in some areas it's currently not very festive in terms of temperatures. http://www.metoffice.gov.uk/weather/uk/se/charlwood_latest_weather_graphs.html

So true, I did say it was only a straw to cling to though :-)

https://twitter.com/BigJoeBastardi/status/410745423867830272/photo/1/large Looking for a small straw to cling to - (apologies if posted already) latest CFS ensembles indicate the AO should switch negative through the last part of Dec and into January.

Was there a noticeable drop in the frequency of the warmings from say 1994 onwards? Just wonder if they're in some way linked in with the Atlantic cycle - I.e. Whether we've seen a reduction in the warm AMO cycle.

Just that there's low confidence in model outputs at the moment, but there's the potential for some stormy weather in a weeks time, primarily in the North and West - if I've understood correctly. Additionally, this week will be boring for the Pro forecasters too with not much to say from day to day - but maybe this is an opportunity for them to just record and repeat the same forecast for the next couple of days and get their Christmas shopping finished instead.

The later stages of the ECM are a mess, indicating a rapid thaw across Scandinavia. In reality I'm sure this is far too progressive.

By the way Joe Bxastardi has tweeted that the latest GFS is probably wrong in how it's handling the us East Coast low.

It may not end up as a straight Northerly though - if we get a short-wave developing in the flow.

Quite likely to be a temperature inversion across the South IMO.

I assume then that In terms of the influence to the South, the Met Office are no doubt factoring the likelihood of a short-wave developing which won't be picked up yet (or details not certain at least), and which will impact on the depth of cold further south. Quite likely you'd have to say at this time of year with the relatively warm sea temps etc.

I think it's just a question of patience. With the QBO phase and the fact we're in solar max (although the sun's gone quiet again for the moment) - there's a really good chance of a decent warming later on - but probably not for another month. I think it's quite ominous though that even with the rampant vortex, we're still seeing a below average November CET and the Alaskan ridging, and possible cold shots from the North. As soon as we see some warming later on, I suspect the vortex's going to get crushed (assuming the broad pattern is similar). Cold lovers need to hope for a late Dec warming, rather than late Jan warming though.

Yep but at t120 it looks as though at least some of the energy ought to be going south of the block - by t144 it seems to push a lot more north. I just think it's the bias in the model - underestimating the trough disruption that should occur. With ECM we've been seeing this almost everyday at t168 energy going south, then at t192 - it's all going north. GFS doesn't bear comment - other than it agrees with UKMO and ECM and t72 now - which is something.

That's true if you use the GFS, however ECM says something very different. In fact its stratospheric forecast is just beginning to hint at something quite tasty. I think it's too early to conclude that the jet will run over the top and sink everything - if that's what you're suggesting.

To add, Based off the ukmo at least, thicknesses down here look pretty good at t120.

Great post Tamara - I think we've got to add the PDO index into the mix - that really switched negative during 2007 and has got to be feeding into buckling the jet across the pacific.

There's are a few papers that have found evidence that it was global in impact. http://explorations.ucsd.edu/research-highlights/2012/research-highlight-the-little-ice-age-was-global-scripps-researchers-say/ "Scripps graduate student Anais Orsi and colleagues found evidence of the same cooling trend in samples of ice from the West Antarctic Ice Sheet. That contradicts prevailing theories that the Little Ice Age was not globally synchronized, but a regional cooling possibly triggered by changes in ocean circulation that created a temperature see-saw effect between the hemispheres." I don't know if the above paper I've linked to above carries that much weight, but it seems to me that Stephen Wilde might be on to something - http://tallbloke.wordpress.com/2010/10/18/stephen-wilde-a-new-climate-model/ if you have prolonged negative NAO and AO conditions, then the jet stream and associated cloud zones should be pushed further south - increasing albedo - creating something of a global effect. From an open minded scientific point of view, I'm hoping the sun stays quiet and we get to put this whole thing to the test.