Provided in the first attachment are the recent (preliminary) southern oscillation index (SOI) values from the Long Paddock site. As of December 23rd, the daily SOI value was way down at -37.16 (the lowest negative daily SOI value of the year), the 30 day avg was down at -7.40, and the 90 day avg was down at -7.10. This is indicative of at least El Nino “like” conditions. That is, conditions that are still neutral, bordering on weak El Nino. According to the GFS model, daily SOI values are to remain generally negative through the rest of 2014. A few more Potential TC's are forecast to pass near Tahiti during the next week or so. There will likely be fluctuations between weak negative and strong negative daily SOI values depending on the proximity of the SPCZ, and each TC/or area of low pressure as it potentially passes near Tahiti. (NOTE: Last night an area of low pressure passed almost directly over Tahiti, but it did not become an official TC as it was just too weak and disorganized). There are currently two other areas of invest in the South Pacific, which could potentially help reduce SLP at Tahiti during the upcoming week. The first invest is 94P, which is on the verge of becoming an official TC at any moment. 94P is currently located at 13.5S, 158.7W with max sustained winds of 30 kt, and a minimum central pressure of 1000 mb. The Second invest is 96P, which fairly disorganized and weak at the moment. 96P is currently located at 13S, 176.9W with max sustained winds of 15 kt, and a minimum central pressure of 1010 mb. Also of interest, is invest 98W of the Western Pacific, which is currently located at 3.5N, 153E with max sustained winds of 15 kt, and a minimum central pressure of 1010 mb. 98W is currently weak, but something to monitor.
The second attachment is of the latest OSCAR data centered on Dec 21st, which shows a portion of the South Equatorial Current (SEC) between 180-140W, is pushing anomalously stronger than normal from east to west (or opposite of what's beneficial to El Nino). This is allowing slightly cooler SST's to flow into the Central Pacific (rather than the other way around where warm water in the west would be allowed to flow towards the east). However, this has improved since the Dec 11th OSCAR data, which showed the SEC pushing east to west stronger than normal from 140E all the way to 140W. The North Equatorial Countercurrent (NECC) has weakened some over the last few weeks, but has no east to west anomalies. The currently surfacing Kelvin wave is likely helping to disguise the east to west flow (of the SEC between 180 and 140W), and helping to keep things from cooling down too much, but once it's done surfacing (or once +3.0 deg C anomalies have surfaced), things may change a bit. At this moment, NO warm water reinforcements (surface or subsurface) are immediately on the way (i.e. downwelling Kelvin wave or westerly wind/anomalies to move warm water from west to east). There are no signs of a La Nina. Subsurface anomalies behind the current downwelling phase (or warm phase) of the Kelvin wave are neutral with very small weak cool pockets. The BOM's Nino 3.4 SSTA forecast model (POAMA), is now in-line with CFSv2 (though NOT NEARLY as strong), suggesting a brief cool down during the Winter/early Spring of 2015 (but staying warm-neutral), before things start warming back up towards borderline weak El Nino conditions by fall of 2015. Who knows...
HAPPY HOLIDAYS!!!