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ENSO Quick
Look IRI ENSO Update / Forecast Technical ENSO Update IRI Probabilistic ENSO Forecast ENSO Prediction Plume Monthly archive ENSO Update21 January 2010SummaryEl Niño conditions remain moderate(+) strength in the equatorial Pacific. For the Jan-Mar season in progress there is an approximately 97% probability of maintaining El Niño conditions. Probabilities for El Niño stay at or above 90% through the Feb-Apr season, decreasing to 55-60% by Apr-Jun season and to the climatological probability of 25% by the Jul-Sep season.General Discussion
During mid-January 2010, the NINO3.4 SST anomaly index continues at
values indicative of a moderate to strong El Niño category.
Until mid-October, the event had maintanined only a weak magnitude,
but intermittently strong westerly wind anomalies from late September
into October, and from late November into December, deepened the
thermocline and substantially increased the SST anomalies in the
central and eastern equatorial Pacific since late October. A significant
accumulation of subsurface heat ensures the persistence of the current
event for at least two more months. As a result of the passage
of moderate strength MJO events, or intraseasonal variability, the wind
anomalies in the western and central Pacific have fluctuated from near-zero
to strongly westerly for several weeks at a time from October to present.
Currently in mid-January there are only weak westerly anomalies, but a
return to stronger anomalies is expected in response to the SST anomalies
that exceed 2 degrees C in the central tropical Pacific, and a relative
lack of anomalously warm SST in the western Pacific. El Niño
conditions are expected to persist at least into early March 2010, and
likely through the middle of northern spring 2010. |
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