About the Forecast Forum

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

AUGUST 2010

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

ENSO Alert System Status: La Niña Advisory      

Outlook:  

            La Niña is expected to last at least through the Northern Hemisphere winter 2010-11.

Discussion:    

La Niña strengthened during August 2010, as negative sea surface temperature (SST) anomalies reached at least -1°C across most of the equatorial Pacific Ocean by the end of the month (Fig. T18).  All of the Niño indices were between –1°C and –1.5°C for the month of August (Table T2).  Consistent with this evolution, the subsurface heat content (average temperatures in the upper 300m of the ocean) decreased further, reflecting the additional cooling of sub-surface waters east of the Date Line (Fig. T17).  Also convection was enhanced over Indonesia, while remaining suppressed over the western and central equatorial Pacific (Fig. T25).  This pattern was associated with a continuation of enhanced low-level easterly trade winds and anomalous upper-level westerly winds over the western and central equatorial Pacific (Figs. T20, T21).    Collectively, these oceanic and atmospheric anomalies reflect the strengthening of La Niña. 

Nearly all models predict La Niña to continue at least through early 2011 (Figs. F1-F13).  However, the models continue to disagree on the eventual strength of La Niña.  Based on current observations and model guidance, we expect the SST anomalies in the Niño-3.4 region to either persist near the present strength, or to strengthen into the winter as is consistent with the historical evolution of La Niña.  Thus, it is likely that the peak strength of this event will be at least moderate (3-month average between –1°C to   –1.4°C in Niño-3.4) to strong (3-month average of –1.5°C or less in Niño-3.4).

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