Does that mean winters over then?
Far from it.
ECM has downgraded it's ENSO forecast a little in May. Looking somewhere between neutral and weak El Nino at present.
http://www.ecmwf.int/products/forecasts/d/charts/seasonal/forecast/seasonal_range_forecast/nino_plumes_public_s4!3.4!plumes!201205!/
CFSv2 going for a weak El Nino from second half of summer.
http://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/nino34Mon.gif
CFSv2 still going for a weak El Nino, though from mid summer now.
And less strong than it was suggesting earlier in May.
12 May
http://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2_fcst_history/201205/imagesInd3/nino34Mon.gif
CFS has switched back towards a moderate El Nino by autumn.
We're emerging from the spring predictability barrier so these forecasts are likely to firm up now. Personal hunch is that the longer the atmosphere delays switching into El Nino phase, the stronger and longer lasting the El Nino will be because more recharge will have happened before warm anomalies reach the surface
The cold PDO does make it harder for an El Nino to get going and sustain and become very strong, but thats not to say you can't get a strong El Nino in a cold PDO phase, I mean the 2009/2010 El Nino was the strongest since the 1997/1998 mega event.
This El Nino does look quite weak though, assuming it even happens. The JAMSTEC model doesn't even go for a proper El Nino, so its certainly not a done deal by any means.
Edited by user 19 June 2012 12:59:42(UTC) | Reason: Not specified
Edited by user 21 June 2012 06:39:46(UTC) | Reason: Not specified
I think that when the MetO forcast a slowing of the rate of warming back in 02'(?) there was a mention of another 'super Nino' type event prior to the resumption of even fast temp rises than the last phase? I also think Hanson has claimed the next nino to be a strong/Super Nino?
If we have had two nina's and a bit of neutral pinning warmer waters at depth for an 'extra long' period would we not expect a fast onset of a strong nino (esp. in the later phases of the PDO-ve?) now?
I always understood the PDO phase to be a delayed response to ENSO, rather than an influence on it. The two may I suppose be self-reinforcing, but the PDO is a mid-latitude phenomenon and the overwhelming direction of influence in ocean-atmosphere teleconnections is from the tropics to the extra-tropics, not the other way round.
That was the 'old PDO' S.C. (not that we know a lot about it as a phenomena?)
What we do know is that temp rises started to affect 'PDO' from the 80's on wards. I recall a fisheries notice , back in the early noughties, advising crews that the PDO was becoming so fickle that they could no longer guarantee long 'phases' (for the Salmon run forecasts up the NW Coast of USA) and that they should keep up to 'daily' updates!
Seeing as the fisheries gave birth to both the observations and early research on PDO I think I should trust there advice?
If you look at the 'new Nino' pattern of warm waters you can see that during PDO-ve type 'horseshoe' events there is plenty of warm ocean to the north of the nino plume? it might be that PDO-ve lessens the S.American coastal El-Nino but cannot influence temps further back into the Pacific?
Anyhow , we all know that temps are just about to start warming up again now the 'cold phase' has ended...........( well! , we never got the cool-down they spent over 10yrs announcing so i thought I'd chance my arm??)
Edited by user 22 June 2012 14:32:47(UTC) | Reason: Not specified
That was the 'old PDO' S.C. (not that we know a lot about it as a phenomina?)
What we do know is that temp rises started to affect 'PDO' from the 80's onwards. I recall a fisheries notice , back in the early noughties, advising crews that the PDO was becoming so fickle that they could no longer gaurentee long 'phases' (for the salmonm run forecasts up the NW Coast of USA) and that they should keep up to 'daily' updates!
Anyhow , we all know that temps are just about to start warming up again now the 'cold phase' has ended...........( well! , we never got the cooldown they spent over 10yrs announcing so i thought I'd chance my arm??)
Are you quite sure S.C.? It is one of the natural drivers that we know least about (only being outlined in the early 80's). by the time we were hacking out 'what it is' it would appear climate warming was already impacting it. As you know a 'phase' can only be fully defined once it has ended (including it's start point) and ,for the current PDO-ve, we have a start point in either 98/99 or nearly ten years later!!! Seeing as some phases only last 15years (or less) we could already be at the end of this one?
Set against a background of rising ocean temp anoms you can see how a surface temp feature could have issues with 'cold phases' milding, 'neutral phases' becoming milder and 'warm phases' becoming longer and more pronounced.
Just check out the northern extent of the 10c ocean isotherm, compared to 30yrs ago, in the 'PDO signature' region! How long before we no longer see bottom waters cold enough to trip the 'PDO-ve' temp regime??
Just like the atmosphere the ocean has circulations throughout it's depth and recent sounding in the Indian ocean and off S.America show the bottom current continuing to rise in temp. Over time the 'cold upwelling' will become a 'mild upwelling'
And anyway, the next spurt of global temp rises (faster than the rises in the 80's we're told) is just around the corner.
Edited by user 22 June 2012 16:53:44(UTC) | Reason: Not specified
I'll be right about the onset of another warming spurt now the 'global cooldown' is over!