>I just took a quick look at NINO3.4 SST Anomalies, and for the week centered on Wednesday May 12th, they’ve dropped into negative numbers: -0.075 deg C.
http://i44.tinypic.com/x10s9y.png
NINO3.4 SST Anomalies – Week Of May 12, 2010
SOURCE
OI.v2 SST anomaly data is available through the NOAA NOMADS website:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite=
Bob Tisdale - Climate Observations 
>I ran a copy of your post at tAV. Thanks.
>Thanks for your work and for your graphs. However, I have one suggestion — could you include more geographical description about each graph? For example, is it global or Mid Pacific or what? Does NINO3.4 refer to a region? Thank you!
>Anonymous: You asked, "Does NINO3.4 refer to a region?"NINO3.4 refers to the area in the central equatorial Pacific with the coordinates of 5S-5N, 170W-120W. It's a common index for the ocean portion of ENSO (El Nino-Southern Oscillation). NOAA's ONI Index is a 3-month running average of NINO3.4 SST anomalies.
>Thanks, Jeff.
>Hey Bob, june-july LaNina territory.Recharging oceans and coolingatmosphere.Watch the coming Arctic ice rebound.Vulcanic eruptions will give additional cooling.You'll be making overtime.Regards KM
>So now the question is, how low will they go? There seems to be a lot of people sure that the decline of this El Nino will be followed by a La Nina, but I know you have shown this is not necessarily, or even usually, the case. As always, watching the ENSO conditions is very thought provoking.
>Isn't it interesting, that the NINO pattern between 1990 and 1998 is exactly as between 2000 and 2010? Starting in neutral conditions, medium, weak and medium El Nino followed by deep La Nina, followed by strong El Nino, followed by even deeper La Nina. Each disappearing strong El Nino hesitates a bit and then falls as rock. Doing simple analogy, following La Nina (if occurs now) will be pretty deep.Juraj V.