IRI ENSO Update / Forecast
Technical ENSO Update
IRI Probabilistic ENSO Forecast
ENSO Prediction Plume
18 March 2010
SummaryEl Niño conditions remain moderate strength in the equatorial Pacific. For the March-May season in progress there is an approximately 85% probability of maintaining El Niño conditions. Probabilities for El Niño decrease to 50% for the April-June season, and to 25% for the June-August season. During the second half of 2010, the probability for La Niña conditions rises to 30%, which is slightly higher than the 25% climatological probability.
During mid-March, the NINO3.4 SST anomaly index continues at
values indicative of a moderate El Niño category, having weakened
somewhat from the stronger levels observed in December and early January.
The event has maintanined a moderate to strong magnitude since mid-October,
modulated by intermittently strong westerly wind anomalies in the western
and central tropical Pacific. Strong westerly wind anomalies during late
January through February allowed the subsurface heat content to maintain
moderately strongly positive anomaly values. This heat content is slowing the
decrease in the SST anomalies, permitting the El Niño episode to
continue well into the northern spring season.