Originally Posted by beyond
Well yes it's all over their website, but no that doesn't mean they use a variable called "El Nino" in their analysis. If you look at their technical pages, where they discuss their methodologies, they do various kinds of analyses (Canonical Correlation Analysis, Linear Inverse Modeling, Markov etc.) based on thousands of SST (Sea Surface Temperature) Anomalies on one side and thousands of continental temp and precipitation measurements on the other. The term "El Nino" is a gloss that the public and the media are familiar with. They will generate maps for instance that predict temps in North Ametica for various certainties of "El Nino like conditions." But the actual analyses don't include this unitary thing called El Niño. If they did, they wouldn't work; it's a gloss for a whole lot of real measurements, not a real thing itself. Also, there are competing underlying explanatory models to generate the sorts of tests and predictions they do. Their cool maps represent a kind of best average outcome for public consumption, with all sorts of probabilities and assumptions attached that are discussed or referenced on other pages.
Point being, not only is "El Niño" not a "thing" suitable for using as a variable in predicting North American winters, it's based on real SST data that none of us here have access to or means to analyze. Nor do we know the variance structure. So "correlating" it to snowfall is, as a British colleague once said, interesting.
Finally, the SST anomalies themselves vary enough that it may be like diagnosing "cancer" to predict an "El Niño" at all. Uh, what kind? Where? What's the prognosis? The so-called Blob and global climate change are other intervening glosses - thousands upon thousands of more data points underneath - that further mess things up, need to be incorporated into an accurate model, n that's what the folks @ NOAA or various universities get paid 2 try 2 do.
The natural world is complicated and messy and parsimony don't get it done. IMO it's OK to live with that, not need black and white outcomes like the talking heads pound at us every moment.
Yea, I've been reading a bunch of their blog stuff as well as the official publications. In simple layperson terms, what I have read says that last year never materialized because the atmosphere didn't really react to SST warmth in observed regions, but this year it is aligning...strongly.
So NOAA issued an El Niño Advisory. Presumably this is because certain regions need to be aware of the potential weather impacts. Here is the longer term 3 month rolling probababilstic forecast. What I see here is a correlation of the various factors that are bundled up as "El Niño" to higher probabilities of a wet Southwest and dry Northwest winter season among other things. I don't know if European weather forecasters bother to track this if warm Pacific surface waters and associated atmospheric conditions don't....I am trying to find some word other than correlate...to weather patterns coming off the northern Atlantic producing snow in the Alps (for example).
I think we all understand that El Niño is not a variable in and of itself, and that "strength" of ENSO 3.4 SST is not an automatic predictor of global weather. However, if equatorial Pacific water temp patterns have never been observed to predictably impact weather patterns in certain regions, it would seem that talking about skiing in those regions in a thread entitled Warm ENSO Region 3.4 Temps and Associated Variable Atmospheric Conditions would be relatively pointless. Maybe even correlated to pointlessness.
"Hey, there's an upwelling of warm equatorial Eastern Pacific surface water in July and a super typhoon driving favorable trade winds, so should I go skiing in Switzerland?"
"Yes, you should go skiing in Switzerland, but not because of super typhoon driven trade winds and an upwelling of warm Eastern Pacific equatorial surface water. Because, and you should know this, super typhoon driven trade winds and an upwelling of warm Eastern Pacific equatorial surface water have no predictable probability of affecting snowfall in Switzerland."
That's a bit tedious, but it's also fun. I think we should start a thread where we can only talk about the variables of El Niño, and instead of saying El Niño, we have to list all of them out each time. That could even be a drinking game, like you have to drink each time someone says "upwelling".