“Where America’s Climate, Weather Ocean and Space Weather Services Begin” Michelle L’Heureux NOAA Climate Prediction Center December 3, 2009 El Niño: What it is, Current Status, and Outlook

2 El Nino: Where are we now? El Niño is present across the equatorial Pacific Ocean Sea surface temperatures (SST) are at least 1.0ºC - 2.0ºC above-average across much of the central and east-central equatorial Pacific Ocean ENSO Alert System Status: El Nino Advisory* * El Niño Advisory: Issued when El Niño conditions are observed and expected to continue.

January Ocean Temperatures ( o C) Comparing Normal to El Niño Temperature Departures Temperatures Strong El Niño Normal El Niño: A aperiodic warming of the central and eastern equatorial Pacific Warm, Wet Cool, Dry Equator

During the last 4-weeks, SSTs were at least 1.0°C above average across much of the equatorial Pacific and more than 2.0°C above average between 180° and 130°W SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks The current El Niño began in June

5 Typical Pattern Changes over the North Pacific and North America El Niño: Pacific jet stream is stronger than average and shifted southward. Flow is more zonal than average from the central Pacific eastward across the U.S.

Temperature and Precipitation Outlooks December February 2010 Winter outlooks indicate: (1) An increased probability of above-average precipitation for southern Louisiana (2) An increased chance of below-average temperature across Louisiana

Figure provided by the International Research Institute (IRI) for Climate and Society (updated 15 Nov 2009). El Nino: Where We Are Headed? Pacific Niño 3.4 SST Outlook Nearly all ENSO models indicate El Niño will continue through the Northern Hemisphere winter The models disagree on the eventual strength of El Niño, but a majority indicate at least a moderate strength El Niño (greater than +1.0°C) through December-January-February A majority of ENSO models indicate El Niño will continue through March-April-May 2010.

Summary El Niño is present across the equatorial Pacific Ocean Based on current observations and dynamical model forecasts, El Niño is expected to last through at least the Northern Hemisphere winter During the winter of (Dec-Feb), El Niño is expected to bring an increased likelihood for above-average precipitation to southern Louisiana and below-average temperature across Louisiana.

“Where America’s Climate, Weather Ocean and Space Weather Services Begin” Back-Up Slides

10 Niño Region SST Departures ( o C) Recent Evolution The latest weekly SST departures are: Niño ºC Niño ºC Niño ºC Niño ºC