CPC and the contributors to the Forecast Forum caution potential users of
this predictive information that they can expect only modest skill.
Niņa is expected to continue for
the next 3 months.
Nina declined to moderate-strength during March 2008 as negative sea surface
temperature (SST) anomalies weakened across the central and east-central
equatorial Pacific. March SSTs were
more than 1.0°C below average in areas between 160°E and 110°W (Fig.
All of the Niņo indices warmed during the month (Table T2), with only the westernmost Niņo-4 and Niņo-3.4 regions having values
nearly 1.0°C below average. Above-average
SSTs remained restricted to the far eastern equatorial Pacific in association
with a significant warming trend that began in mid-December. In the central
Pacific, the subsurface temperature anomalies also lessened (averaging −1°C
to −4°C at thermocline depth), and became increasingly confined to the
surface region (Fig. T17).
This evolution led to a significant weakening of the negative ocean heat
content anomalies (average temperatures in the upper 300m of the ocean).
Despite this oceanic trend, the atmospheric conditions continue to
strongly reflect La Niņa. Enhanced
low-level easterly winds and upper-level westerly winds persisted across the
central equatorial Pacific (Figs. T20 and T21), convection remained suppressed throughout the
central equatorial Pacific, and enhanced convection covered the far western
Pacific (Fig. T25). Collectively, these
atmospheric and oceanic conditions indicate an ongoing, but weaker, La Niņa.
recent dynamical and statistical SST forecasts for the Niņo
3.4 region indicate La Niņa will become weak and persist
through May-June-July 2008 (Figs. F1- F13). Thereafter, there is considerable spread in the
forecasts, with nearly one-half indicating La Niņa could continue well into the
second half of the year. Based on current atmospheric and oceanic conditions and
recent trends, La Niņa is expected to continue for the next 3 months.
updates of oceanic and atmospheric conditions are available on the Climate
Niņo/La Niņa Current Conditions and Expert Discussions).