Provided in the first attachment are the recent (preliminary) southern oscillation index (SOI) values from the Long Paddock site. As of November 8th, the daily SOI value was down to -21.89, the 30 day avg was down to -12.31, and the 90 day avg was down to –8.60. This is indicative of at least El Nino “like” conditions. That is, conditions that are still neutral, bordering on weak El Nino. The GFS model still suggests that SLP at Tahiti is to rise some by mid next week. If that were to occur, it would likely result in weaker negative daily SOI values. This would also happen to coincide with old moderate negative daily SOI values exiting the 30 day avg. Therefore, if current projections hold true, the 30 day avg will likely either level off or even rise slightly during that time. For now, I suspect that the 30 and 90 day avg will continue dropping with the 30 day avg possibly dropping to below -13 or -14, and the 90 day avg possibly dropping to near -9.
The second attachment is the CDAS Nino 3.4 index (courtesy Levi Cowan), updated Nov 8th at 12Z, which per this data suggests that SSTA in the Nino 3.4 region are up around +0.828. The red line is a rough estimate by eyeball (no math involved) of the trendline.
The third attachment of the TAO plots of 5 day subsurface temps (top) and anomalies (bottom) for data valid through Nov 7, shows that there are currently warm subsurface anomalies from the dateline region to the Galapagos Islands. There's even a few pockets of +3.0 deg c anomalies popping up. The downwelling Kelvin wave back at 155W still has anomalies being measured in the +4.0 degree C range. Per this data, there's nothing on the subsurface that would suggest any immediate threat to warm SSTA. Fluctuations from day to day or week to week are imminent, but overall, SSTA in the Nino 3.4 region are likely to continue gently warming or at least hold. Possibly through the New year. Unfortunately (for CA drought), as discussed in a quote I provided a while back from NOAA, based on climatology, during November-December-January, SSTA in the Nino 3.4 region typically need to reach +1.5 deg c above normal in order to fully influence global weather patterns (ie. Enhance the jet stream and change the storm track). After doing some research of historical rainfall records from Santa Barbara, CA. I discovered the following: During the weak El Nino of 2005 Santa Barbara received 36.94 inches of rain!! During the weak El Nino of 2007 we received 6.41 inches of rain. So, 2 weak El Ninos, but 2 totally different rainfall totals. So, it's really 50/50, but I would like to hope that since some of the low pressure systems in the North Pacific this year have been slightly stronger than normal while the high pressure systems have been slightly weaker than normal, we'll at least see a normal rain year (18.46 inches). I realize a normal rain year for drought areas wont solve anything, but the thought of another year of less than 9 inches of rain is terrifying. For the CA drought it would be a consequence not have an El Nino, as long as it wasnt a Super El Nino.
JayW,
Sorry if there was any confusion! I was just saying that if one wanted to attempt to forecast the SOI values issued by the long paddock site, the GFS forecast for the time of day around 12Z corresponds well with the official daily SLP readings (for Tahiti and even Darwin) issued by the Long Paddock (daily SLP readings are of course then used to compute the daily SOI values). I don't know why this works, but it does. Since weather (high and low pressure) is ever changing/moving, SLP readings at Tahiti and Darwin will change/vary throughout the day. So again, I was just saying that while the SOI is hard to forecast (that's why there aren't very many forecasts for the SOI out there, it's too volatile), I found a method for forecasting it that sorta works, (about 65-70% of the time). Notice in the 4th attached image, which shows the November 10th forecast for SLP at Tahiti, 06Z top and 18Z bottom, the forecast for SLP at Tahiti changes throughout the day (or 24hr period). The same thing also happens at Darwin, but SLP usually changes less for that region (at least recently). Anyways, if the total difference between the two regions is 2 or 3 mb (here's a completely made up example, say at the 00Z SLP for Darwin=1010 mb Tahiti=1013 mb VS. 12Z Darwin=1011 mb and Tahiti=1011 mb) it can mean the difference between weak positive or weak negative daily SOI values. Also, if the latest daily SOI value is say -12 and the daily SOI value exiting the 30 day avg is say -14, then the 30 day avg will rise. However, if the daily value is -15 but the value exiting is -14, then the 30 day avg will fall. So basically a tiny adjustment can affect all SOI values. Using the forecast for the 12Z (that specific time of day) corresponds well with what ends up being issued by the long paddock site (not always but close enough that with practice it usually works pretty decent). So we're only talking about GFS forecasts for the 12Z time of day working best if one were trying to make a possible prediction in regards to the Long Paddock SOI values. Sounds crazy but it's true.
Edit: I had to correct the 4th attached image as I accidentally posted different days. It's fixed. The other part of the formula is knowing when or when not to believe the forecast model (basing a human forecast just on model forecast data alone will almost always let you down. The model can be 100% wrong sometimes and then be 99% accurate a week later). Part of that would be factoring in the recent trends in actual/official daily SLP readings and SOI values issued by Long Paddock. So that's where the practice comes in. I think it helps too that Surfline.com has tweaked their GFS SLP model. It's actually very similar to the earth wind map, in that it allows you to zoom in and out and view any possible location around the globe (up to 372 hours out). In fact, it allows you to zoom in so far in that I can fill up the whole computer screen with just the tiny Islands of Tahiti. That very small advantage allows you to see exactly what the SLP forecast is for Tahiti. Without having to guess or eyeball it.
Thanks,
bigB