El Nino signs weaker this month

Oct. 4 2012
An already weak El Nino forecast for this winter got a little bit weaker after September’s ocean temperature readings and other data were analyzed by the US Climate Prediction Center. The Center’s latest forecast noted that sea surface temperatures cooled a bit in September but still remained barely above normal. The same trend was true in the upper 300 meters of the ocean. These temperatures would normally be rising if we were headed into an El Nino event, but instead they grew cooler in September. The only sign of movement toward El Nino conditions was the presence of low-level westerly wind anomalies over the western Pacific, but upper-level and lower-level winds across much of the Pacific remained near average. And while tropical convection increased over the International Date Line, which could be a sign of a coming El Nino, it also remained elevated over eastern Indonesia, which is farther west than expected. So overall, a very mixed bag and, at least for this month, a suggestion that the chances for an El Nino event have grown weaker.