CPC and the contributors to the Forecast Forum caution potential users of
this predictive information that they can expect only modest skill.
Alert System Status: El
El Niņo is expected to
continue and last at least into the Northern Hemisphere Spring 2010.
Niņo strengthened from October to November 2009, as sea surface temperature
(SST) anomalies increased across the central and eastern equatorial
The monthly Niņo-3.4 index value increased to +1.7°C (Table T2). Consistent with this
warmth, upper-ocean heat content anomalies remained positive, and subsurface
temperature anomalies shifted eastward across the eastern Pacific, with the
largest departures exceeding +4°C by the end of the month (Fig. T17).
Also, the low-level and upper-level wind anomalies over the equatorial Pacific
were highly variable during the month due to the Madden-Julian Oscillation (MJO;
The MJO also contributed to anomalous convection over
and the west-central equatorial Pacific (110°E to 180°; Fig. T11).
Collectively, these oceanic and atmospheric anomalies reflect a moderate
strength El Niņo.
disagreement remains among the models as to the eventual peak strength of El Niņo
(Figs. F1-F13). Even at short lead times
(e.g. November-December-January), SST forecasts for the Niņo-3.4 region range
from +0.5 to +2.0°C. At this point,
it seems equally likely that El Niņo will either strengthen further or remain
at moderate strength (3-month Niņo-3.4 SST index of +1.0 to +1.4°C) during the
next few months. Regardless of the
precise peak strength, El Niņo is expected to exert a significant influence on
the global weather and climate in the coming months.
Most models indicate El Niņo to persist through March-April-May 2010,
with SST anomalies in the Niņo-3.4 region beginning to decrease somewhat in
updates of oceanic and atmospheric conditions are available on the Climate
Niņo/La Niņa Current Conditions and Expert Discussions).