beng

LOL yes - however there's more to the UK climate than the PDO - I don't think it's done us many favours (considering the global climate warming trend) in terms of cold winters in recent years though.

Thanks Kold - totally agree we're not in La Nina yet, but i think it's coming - although as you say it may take a few more months. Just been reading up a bit recently on the pacific patterns in response to the large negative anomaly there - the following links are quite interesting: http://science.nasa.gov/headlines/y2000/ast15sep_1.htm http://www.ispe.arizona.edu/climas/learn/pdo/index.html http://www.srh.noaa.gov/abq/feature/PDO_NM.htm I think the anomaly there relates to the PDO cycle - and it does appear we may be entering a negative phase of this cycle before too long. Indeed one of the above articles backs up what you said by mentioning that the positive phase of the PDO tends to enhance El Nino winters and suppress La Nina winters. Actually looking at today's SSTs http://weather.unisys.com/surface/sst_anom.html - you can almost see the horseshoe shape characteristic of a negative PDO. Ben

http://weather.unisys.com/archive/sst/sst_anom-070506.gif http://weather.unisys.com/surface/sst_anom.html I'm not sure if I agree with the comments regarding la nina waning. Certainly the pattern didn't really seem to get going during April - however in the last 10 days (and I've been checking the charts daily) the La Nina pattern is now showing good signs of developing. Have a look at the above 2 links and you'll see what I mean. Most of the forecasts I believe are for it to develop early Summer - and this IMO now seems to be happening. Anyway I agree that the signal is there for a negative NAO based on the MO methodology - probably hard to say how negative. What do people think of the state of the North Pacific though? Seems quite cool - presumably if this pattern is there into the winter, then the effect would be a weakened Pacific jet - and potentially a colder than normal winter for N America? This might also have implications for the NAO. Would we be right in saying that the PDO signal is now entering the negative cycle? The last real negative cycle was from around 1947-75 http://www.srh.noaa.gov/abq/feature/PDO_NM.htm If so then perhaps we can expect a slow down in the current level of warming.

Thanks SH - that's astonishing! Firstly that it could be 9c colder than the previous April - but secondly astonishing as to how warm (relatively) the previous April up there must have been. Thanks to Carinthian for keeping this thread going too - quite interesting that the ice melt this year seems a bit slower than last year - maybe due to the big positive AO last winter?

I'm probably being thick - it's early http://nwstatic.co.uk/forum/public/style_emoticons/<#EMO_DIR#>/cool.gif Where can I set my signature details? I can't seem to find the option under my profile. Don't worry found it.

I will go for a CET 11.8c which is +0.5 above the 71-00 average. I'm also going for a wet month with slow moving low pressure systems running across (or to the South) the UK giving some fairly thundery conditions at times

Some very warm predictions on here (hardly surprising though given what we've seen)! I'm going to go for 11.8c (+0.5 above the 71-2000 average). I'm actually expecting a fairly wet month - which would go against most of the longer range models at the moment (except possibly ECM) - based on the developing cold SSTA off the US east coast, coupled with those to our North helping to push the jet somewhat further South than we've seen. I can actually see it running through the middle of the UK as the month progresses so we might see a trail of rather slow moving Atlantic depressions. We could also see a few thundery downpours given the warmth that's around.

7.5c - mostly mild and wet.

Thanks for the replies - I am quite surprised though that we are fairly close to the sea ice average extent at the moment - at least from what Cryosphere today reports - but I guess the very positive AO has helped focus the cold that's around over the arctic circle and the sea ice areas (with a few exceptions).

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/arctic.jpg Hi Carinthian, What do you make of the satellite image of ice extent - seems to show an ice bridge forming between Greenland/Iceland - which would be quite a bizarre thing to happen in such a mild winter? Many thanks Ben

6.1

Hi Tamara, yes I'm hopeful that the new warming event is more favourable for us - I think we need to be looking at the 5hPa level to see where the current warming is and if I'm looking correctly - it's shifted a little - although not a lot. http://www.cpc.ncep.noaa.gov/products/stra..._t05_nh_f48.gif by 168 hours it looks a bit more promising though - but we could be talking last week in Jan before the effects are felt down here with the PV perhaps shifting towards Scandi http://www.cpc.ncep.noaa.gov/products/stra...t05_nh_f168.gif Have to admit though, I'm still getting my head around the stratospheric warming charts so I may be wrong.

Just thought I'd bring this thread back up - since Jack's question about whether the stratospheric warming would produce high pressure over Alaska during early Jan - and leave Europe zonal - looks like your question has been answered by the models now. Very interesting though to see the strong relationship between the stratospheric warming and the weather on the ground though.

http://weather.unisys.com/surface/sst_anom.html For anyone interested, there's been a definite weakening of El Nino in the area just off the S American coast - I would presume this may have implications for the PNA pattern through the winter - as well as the jet strength. Also - hopefully we'll see a weakening of the warm pool south of Newfoundland as the cold pool over NE America moves out to sea.

I didn't realise that Nov 30 was the cut off, but it makes total sense when I think about it! Feel free to ignore my guess - it's probably wrong anyway! lol

http://www.ssd.noaa.gov/PS/SNOW/ARCH05/USA...2005358_usa.gif http://www.ssd.noaa.gov/PS/SNOW/ARCH05/USA...2005360_usa.gif 26th Dec 2005 was when Hudson Bay finally completely froze over last year - that was pretty late I'd think relative to the norm - but i might be wrong.

4.5c

Okay so correct me if I'm wrong, but basically what we're saying is that it's okay for Greenland to be below normal (maybe even beneficial) at this time of year (indeed it should enhance the sea ice situation directly to our North) - but when we get to winter proper, we should look for that cold to transfer off the icesheet, West or East - otherwise we face a polar vortex over Greenland with a resulting zonal atlantic. PS Glad you came back Carinthian :lol:

Hi Carinthian - I've got an email from Ian Currie who does our local forecasts saying that a tongue of ice was as far south as the Northern Isles in the summer of 1888 preventing the fishing fleet from entering the harbour in the Faeroes. Snow fell over all high ground in northern England that summer. I would imagine the ice extent was similar in the really cold episodes of the 16th/17th/18th centuries too. :lol: PS Thanks Tamara - nice to have someone respond to what I posted

Just to back up something Carinthian's just posted - it's been very noticeable to me how we've not seen hardly any (if any) low pressure systems drive from the SW to the North of Scandinavia and then on into the Barents region so far this Autumn (certainly not the case though over the previous 10 autumns). I do remember hearing that there's a proven correlation (not sure how strong) between low pressure being blocked from that path during autumn and colder winter conditions over Europe. You can see from the latest UKMO chart at 144 hours http://85.214.49.20/wz/pics/Rukm1441.html and from the GFS jet chart at the same time http://85.214.49.20/wz/pics/Rtavn14415.png that if the cold to our NE continues to build (and it might not I suppose if the jet really cranked up) that it won't be long now before the cold pool there and the subsequent likely build of cold in Scandinavia forces the jet further south around our longitude. I'm not sure I buy the current GFS FI, but we'll see. :lol:

Looks like they'll warm up by this time next week - judging by the latest model output. But it's Autumn so you'll get ups and downs.

http://uk.weather.com/weather/climatology/RSXX0063 Temps would be below average there for the time of year if that happened. :lol:

Yes and this is confirmed by looking at the predicted temperature anomolies for Berlin. http://www.climaprog.de/website1006007.htm Roeder is going for an extremely cold winter based on this methodology - of course it remains to be seen how things will actually turn out.

9.9c - I think we're about to start another run of below average CET months.

try this http://alk.tiehallinto.fi/alk/kelikamerat/LQ201653.jpg :blink: