Update: El Nino strengthens


CPC graphic shows Tropical Pacific SST’s warmed rapidly the past few weeks.

An updated monthly report today from NOAA’s Climate Prediction Center shows El Nino is gaining strength in the Pacific Ocean. Sea surface temperatures in the tropical Pacific rose as much as 1 degree Celsius in October. Large areas of the tropical Pacific Ocean are now +1.5 degrees Celsius above average.

The CPC forecast for this winter remains for at least a moderate strength (3-month Niño-3.4 SST index of +1.0°C or greater) El Nino. According to the CPC, the anticipated effects of this level El Nino include:

“For the contiguous United States, potential impacts include above-average precipitation for Florida, central and eastern Texas, and California, with below-average precipitation for parts of the Pacific Northwest. Above-average temperatures and below-average snowfall is most likely for the Northern Rockies, Northern Plains, and Upper Midwest, while below-average temperatures are expected for the southeastern states.”

The latest CPC three month outlook for Dec-February highlights the anticipated warmth in the northern states.


The various CPC models show wide disagreement on the eventual strength of El Nino this winter. From the CPC discussion:

“There continues to be disagreement among the models on the eventual strength of El Niño, but the majority indicate that the three-month average Niño-3.4 SST index value will range between +1.0°C and +1.5°C during the Northern Hemisphere winter (Fig. 5). Consistent with the historical evolution of El Niño, a peak in SST anomalies is expected sometime during November-January. At this time, there is a high degree of uncertainty over how long this event will persist. Most of the models suggest that this event will last through March-May 2010, although the most likely outcome is that El Niño will peak at least at moderate strength (3-month Niño-3.4 SST index of +1.0°C or greater) and last through at least the Northern Hemisphere winter 2009-10.”

It will be interesting to see how strong this El Nino will be as it reaches maturity in the coming months.


  • Jim Southwick


    I’m a transplanted Minnesotan living in Switzerland, looking forward to winter here. Is there a trend for how an El Nino tends to affect winter in Western Europe? Thanks! Jim S.