phil nw.

That makes sense Interitus as it could explain some of the varying readings we have seen run to run. I am wondering how much effect the trending upwards of the overall AO will have come month end. I would think the more fragmented the vortex remains the better chance of a -ve OPI by month end. Not a straightforward measure to follow that;s for sure.

Yes let's see if the November updates keep this trend before we lose any more hope wrt a colder Winter. Even if they prove anywhere near in their projections then there are always chances of some cold spells within an overall slightly milder than average season. Remember we only need one good Stratosphere warming along with with the odd northerly in the rear of a passing low-not much to ask. A few days or a week or two within the 3 months of some snow and a few frosts would certainly be an improvement on last year.

The Atlantic pattern is certainly looking typically Autumnal now with the Jet aiming across our latitude over the next few days. A look at the NH flow from the latest 06zGFS run shows it digging well into mainland Europe.The second image shows the boundary layers between the air masses north and south of it and why the projection of a warm up over Western Europe shows in the charts Gavin(SS)posted above. the milder air looking likely to be over the UK until around the middle of next week but cloud and rain or showers never far away. The latest Fax for T84hrs showing plenty of frontal systems around to ensure the changeable theme continues. Later next week there are signs of a return to cooler weather moving across from the west in a brisk westerly flow with bands of rain or showers the outlook into week 2. This does look like an ongoing pattern towards month end with the heights to our north trending lower and the jet continuing to flow across mid-latitudes for the foreseeable.

Not much to add really.We only need to look at recent modelling to see the way the NH pattern has evolved. Yes there still +ve height anomalies over the pole and can appear quite alluring but when the one area of lower heights are to our NW towards Greenland with a corresponding Euro/Azores +ve anomaly then it can mean only one thing. The ECM mean charts at day 10 anomalies/and 500 pattern along with last nights NOAA mean forecast for days 8/14. it may cool off somewhat in week 2 after the weekend warm pulse as the jet flattens out bringing in the flow more from the west or north west at times but really we are just looking at our normal Autumn set up.

I happened to catch a TV show last night about your area C,it looks lovely.Yes wrt the impending warmth expected it could be bad news for snow advancement south and west at month,s end. Currently plenty further NE but the expected Euro block with the trapped warmth, whilst good for an Indian summer,may just have come at the worst time for the SAI. Let,s hope this does not prove a factor in Winter cold prospects.

It seems to be a problem on that site as I am getting the same result Yarmy.Ours seem OK thoughhttps://max.nwstatic.co.uk/gfsimages/gfs.20141013/06/72/h850t850eu.png If you want to view the GFS 06z run. A good image of the approach of the tropical maritime air mid week.

Yes a good assessment Nick. A very solid looking South Westerly pattern for the rest of the month it seems. The mild air looks like getting well into the European mainland next week too. I would imagine some warm sunshine on some days over there Corinthian.

Short term it looks OK for further snow over there with the modelling of the Russian trough digging south. I have to say though i am less optimistic beyond next week going by the anomaly charts. http://modeles.meteociel.fr/modeles/gens/naefs/run/naefsnh-0-0-240.png?0 http://www.meteociel.fr/modeles/ecmwf/runs/2014101200/EDH101-240.GIF Signs of a badly orientated euro block and +ve 850,s could halt advancement south and west. Let,s hope for some changes to that outlook before the end of the month.

Yes agree Gibby.Certainly the overall Atlantic pattern is evolving into a typical Autumn,changeable outlook.some quite mild days at the end of the week as the next Atlantic low stalls and draws in some muggy tm air into the UK. The mean charts showing continental heights and Atlantic low pressure as we go through the nextwek/10 days.

Great intro Ed. So another season begins,always a good thread to follow as it adds another dimension to model watching.

That's how i see it. The current figure is merely a forecasted index because we do not have the full 31days of historical data. As you say 10 days actual(to yesterday)+10 days forecast =20 days leaving still 11 days with no imput,either historical or forecasted. As i suggested above there's plenty of wiggle room either way before the final OPI is ascertained.

I am sure it would be that Ed, going by his original explanation. As we know FI modelling will often show wild swings from one run to the next.How often do we see changes in the polar 500hPa pattern at even closer range? Surely this will reflect on the OPI projection of the PV profile? With only 11 days recorded and 10 days forecasted then there's plenty of time for movement on this yet.

Following the ens the actual AO was always trending back up after this week,but still on the mean negative side.Although the OPI is based on different data this must affect it somewhat although that is quite a jump I agree. I suppose we are still going into FI territory and tonights gefs have quite a wide spread on the AO graph so swings on this are still likely until we have more actual days recorded later in the month.

Yes come on folks let,s keep the moans about the weather charts not each other. If you must go down that route better to use a pm. Thanks.

It does look like the changeable theme continues into next week. No sooner are we rid of the current low than another Atlantic low approaches us around mid week. http://www.wetterzentrale.de/pics/Recm1201.gif Warmer uppers as the flow turns more south or south west but accompanied by further rain or showers through the rest of the week. With the southerly mean position of the jet heading near the Uk any settled weather looks unlikely for the time being.

They use the term westward and eastward which is confusing MS. Westward is going west ie flowing from the east so negative or East QBO is how i understood it.Checked and link here- http://dictionary.cambridge.org/dictionary/british/westward so would ring true for eastwards, ie,westerly flow or positive QBO.

Yes ECM mean at D10 ht anom and 850 temps a little warmer for us,by day anyway but chances of frost and some fog night times under any slack conditions.Conversely note the cold to the east over Scandinavia/Russia .digging well south by that time. The lowest polar heights being modelled around Siberia and with the Atlantic flow quite sluggish this may well be a period where the cold pool further east starts to establish.

Let,s keep on topic,ie models please chaps. Ta.

Yes indeed.Let,s enjoy those views whilst we can,before the daylight goes altogether.

Thanks for that C.I have bookmarked the link. It looks lovely in the setting sun with snow and ice just forming now. My wife and I were up there in July 2011 on an Arctic cruise we couldn't, dock at Longbyern because of ice floes still in the inlet. A wild and beautiful area though. Hopefully we can get a taste of those scenes in Europe this Winter.

Interesting Steve so i wonder how they get the rolling forecast of their version of the index from the GFS as the month goes on? Would that not simply be the AO index as i understand it? Is there a link to a full explanation of the OPI as opposed to the basic October AO index ,if there is it would be beneficial to all. edit just had another re read of the first post and i think i have answered my own question. They feed into their dedicated software those daily GFS charts and the forecast ones for up to 10 days ahead and it works out from the 500hPa patterns their OPI.Indeed a basic -AO pattern would underpin a -ve OPI but i think i get the difference now. Someone correct me if i have it wrong.

Hi Nick, See my post no 25 above where i have done that.

Steve as i understand it the OPI is simply another way of showing the NH 500hPa pattern AO for October and Recarrdo's findings on the graph show a .91 correlation to the subsequent Winter AO ? In any event it doesn't really alter my presentation re measuring the coldest Winters CET against the preceding October. It's an interesting discussion and i appreciate the work you have also done which i see you widened to iclude the NAO. Kentish Blues Man in a very good post above explains the possible pitfalls of concentrating on just the AO for the Winter quarter and underlines more fully why i took the CET series rather than the Winter indexes to compare with the preceding Octobers. In any event it does no harm to come at this from different perspectives,it's the way we learn more and hey this isn't an excercise to show who is right or wrong.

Yes the way you understand it is how i interpreted it BW. Btw folks to avoid any confusion my post above does not detract from the impressive link between the Oct OPI and the Winter AO following. Knowing that a -AO can sometimes not work in our favour,ie we could have one that's too west or east based and end up on the wrong side of any blocking i thought a study related to our own Winter CET and the OPI was more useful for us. As it turns out nothing proved either way except that recent cold UK Winters have been recorded from both - and +ve OPI indexes. In fact based on my findings we could still have a slightly positive OPI and get a colder Winter,so no reason to pin everything on this. That really was my point ,maybe i should have made this clearer in my earlier post.

The graph shown by the researchers linking the OPI to the following Winter index is quite compelling. the 2 lines quite close together. This inspired me to have a slightly different look at the possible link wrt the October index to the subsequent Winter for us specifically in the UK. For this i had a look at the CET time series of the colder Winters since 1960. To get a reasonable analysis with a sufficient number i chose any Winters with a CET of 3.5C or below,which amounted to 16.Alongside i have entered the AO index of the previous October. For example in the first one i have took October 1962 AO and put alongside the 1963 Winter and so on. These are(January of year), 1963 -0.02,1964 1.07,1965 0.34,1968 1.30,1969 -1.01,1970 0.10,1977 -0.80,1979 0.90. 1982 -1.17,1985 -0.27,1986 1.04,1987 1.43,1991 0.66,1996 0.08,2009 1.68,2010 -1.54 this comparing actual coldest recent UK Winters(well since 1960 anyway)with the October AO preceding them.This is in order to see if there is any link between cold UK Winters and a negative October AO prior to them. As we can see around 50% had +ve October AO readings,although most only marginally so. Admittedly this is a somewhat different measurement to the originators idea who compared the following Winter's AO index.This is quite a wide ranging pattern for the hemisphere.I am looking at linking the cold British Winters via CET measurement against the preceding October AO.to see how this may impinge on our little corner of the Northern hemisphere. Just a little slant on things if you like. What we can deduce from this little sample is there is no strong link in recent times. Another interesting find that came out of this was that a good number of those cold Winters had west based QBO's.They were 1964,1965,1968,1970,1979,1986,1991,1996 and 2009-more than half. link to QBO data http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html Putting those years into a composite NH 500hPa anomaly for the preceding Octobers we get this. as you would expect we are looking for a sharp Scandinavian trough off the main PV digging cold Arctic air south.This would normally help with Eurasian snow cover below 60N as we go towards month end to aid Cohen's theory. It seems a Euro block far enough west does not necessarily mean bad news as it can help filter cold air over the top down into E.Europe/W.Russia.