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ENSO Forecast Discussion

ENSO and SST Model Forecasts

Canonical Correlation Model
Nino 3.4 Region: Historical  F1
Nino 3.4 Region: 0-4 Season  F2

NCEP Coupled Model
Eq. Pac. SST & Anomalies  F3
Nino 3 & Nino 3.4 Region  F4

NCEP Markov Model
Eq. Pac. SST & Anomalies  F5
Nino 3.4 Region  F6

LDEO Model
Eq. Pac. SST & Wind Stress Anoms  F7
Nino 3 Region  F8

Linear Inverse Modeling
Global Tropical SST Anomalies  F9
Nino 3.4 Region: Historical  F10

Scripps/MPI Hybrid Coupled Model
Eq. Pac. SST & Anomalies  F11

ENSO-CLIPER Model
All Nino Regions & SOI  F12

IRI Compilation of Forecasts
Nino3.4 Region  F13

Forecast Forum

JUNE 2008

The CPC and the contributors to the Forecast Forum caution potential users of this predictive information that they can expect only modest skill.

     Outlook:  

            ENSO-neutral conditions are expected to continue into Northern Hemisphere Fall 2008.   

      Discussion:    

A transition from La Niña to ENSO-neutral conditions occurred during June 2008, as sea surface temperatures (SSTs) returned to near-average across the central and east-central equatorial Pacific Ocean (Fig. T18).  Also, positive SST anomalies continued in the eastern equatorial Pacific. Consistent with this pattern, the latest monthly SST index was -0.3°C in the Niño-3.4 region, and +0.6°C in the Niño 1+2 region (Table T2).  The subsurface oceanic heat content (average temperatures in the upper 300m of the ocean) and patterns of subsurface temperature anomalies (Fig. T17) also reflected the transition to ENSO-neutral conditions. Positive heat content anomalies were associated with above-average temperatures at thermocline depth across the entire equatorial Pacific, while small negative subsurface temperature anomalies persisted near the Date Line between the surface and 75m depth.

Similar to past transitions, La Niña continues to linger in the atmospheric circulation, but with diminishing strength. Enhanced low-level easterly winds and upper-level westerly winds remain across the central equatorial Pacific (Figs. T20 and T21), while convection continues to be suppressed in the central equatorial Pacific and slightly enhanced over the far western Pacific (Fig. T25). Collectively, these atmospheric and oceanic anomalies are consistent with a return from La Niña to ENSO-neutral.

Most of the recent dynamical and statistical SST forecasts for the Niño 3.4 region indicate ENSO-neutral conditions (−0.5 to 0.5 in the Niño-3.4 region) will continue through Northern Hemisphere Winter 2008-09 (Figs. F1- F13).  Despite this model consensus, the possible development of El Niño or La Niña cannot be ruled out due to uncertainty in model forecasts and because ENSO events often form during the second half of the year. Based on current atmospheric and oceanic conditions, recent trends, and model forecasts, ENSO-neutral conditions are expected to continue into Northern Hemisphere Fall 2008.  

Weekly updates of oceanic and atmospheric conditions are available on the Climate Prediction Center homepage (El Niño/La Niña Current Conditions and Expert Discussions).