Skip Navigation Links 
NOAA logo - Click to go to the NOAA home page National Weather Service   NWS logo - Click to go to the NWS home page
Climate Prediction Center

Expert Assessments
   ENSO Diagnostic
     Discussion Archive

About Us
   Our Mission
   Who We Are

Contact Us
   CPC Information
   CPC Web Team

HOME > Expert Assessments > ENSO Diagnostic Discussion
issued by
6 November 2008

Spanish Version


Synopsis: ENSO-neutral conditions are expected to continue into early 2009.

ENSO-neutral conditions continued during October 2008, as equatorial sea surface temperatures (SSTs) were near-average across much of the Pacific Ocean, except for small areas of below-average SSTs in the east-central Pacific and off the coast of South America (Fig. 1). Correspondingly, the latest weekly SST index values were near-average in all Nio regions except for Niño-1+2 (-0.8C, Fig. 2). Subsurface oceanic heat content anomalies (average temperatures in the upper 300m of the ocean, Fig. 3) became less negative due to the eastward shift of positive temperature anomalies at thermocline depth to ~160W, but anomalies remained negative in the eastern half of the Pacific (Fig. 4).

The atmospheric winds and convection patterns exhibited a high degree of week-to-week variability across the tropical Pacific during October in response to the Madden-Julian Oscillation (MJO). The cumulative effects of the MJO were above-average convection over Indonesia, and enhanced low-level easterly winds, enhanced upper-level westerly winds, and suppressed convection over the western equatorial Pacific. Overall, the ocean-atmosphere system remains consistent with ENSO-neutral conditions.

A majority of the SST forecasts indicate a continuation of ENSO-neutral conditions (-0.5C to 0.5C in the Niño-3.4 region) into the first half of 2009 (Fig. 5). Several dynamical models suggest the development of a La Niña during Northern Hemisphere Winter 2008-09. This outcome becomes more likely if the current MJO were to stall in a location that favors enhanced low-level easterlies and increased upwelling in the east-central and eastern Pacific. However, it is rare for La Niña to develop late in the year. Therefore, based on current atmospheric and oceanic conditions and recent trends, ENSO-neutral conditions are expected to continue into early 2009.

This discussion is a consolidated effort of the National Atmospheric and Oceanic Administration (NOAA), NOAAs National Weather Service, and their funded institutions. Oceanic and atmospheric conditions are updated weekly on the Climate Prediction Center web site (El Niño/La Niña Current Conditions and Expert Discussions). Forecasts for the evolution of El Niño/La Niña are updated monthly in the Forecast Forum section of CPC's Climate Diagnostics Bulletin. The next ENSO Diagnostics Discussion is scheduled for 11 December 2008. To receive an e-mail notification when the monthly ENSO Diagnostic Discussions are released, please send an e-mail message to:

Climate Prediction Center
National Centers for Environmental Prediction
NOAA/National Weather Service
Camp Springs, MD 20746-4304

NOAA/ National Weather Service
National Centers for Environmental Prediction
Climate Prediction Center
5200 Auth Road
Camp Springs, Maryland 20746
Page Author: Climate Prediction Center Internet Team
Page last modified: November 6, 2008
Information Quality
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities