El Niño Weekly Update [21 Dec 2009]

FEWW Comments on the ongoing El Niño:

• Pacific Ocean surface temperature anomalies are at their highest in the past 12 years, exceeding the anomalies recorded in the  1997-98 El Niño.

• The precipitation remains high near the equator, and low in places like Australia.

• The ongoing drought and deluge would cause substantial damage to crops and infrastructure.
• Extremes of climate enhanced by El Nino in 2010 could contribute to food shortages in many parts of the world.

• In June 2009 FEWW Moderators estimated that a new episode of El Niño would have devastating impact globally and  could cause up to $500 billion in damages.

ENSO Cycle: Recent Evolution, Current Status and Predictions

El Niño Weekly UPDATE prepared by Climate Prediction Center / NCEP –  21 December 2009

Click image to enlarge. Source: Climate Prediction Center / NCEP

The latest weekly SST departures are:

• Niño 4   ~  1.4ºC
• Niño 3.4  ~  1.8ºC
• Niño 3 ~ 1.6ºC
• Niño 1+2 ~ -0.2ºC

El Niño Map. [SOURCE: NOAA/ Climate Prediction Center / NCEP]

SST Departures (°C) in the Tropical Pacific During the Last 4 Weeks
During the last 4-weeks, SSTs were at least 1.0°C above average across much of the equatorial Pacific east of 170ºE, and more than 2.0°C above average across portions of the eastern half of the Pacific.

Click image to enlarge. Source: Climate Prediction Center / NCEP

Global SST Departures (°C) During the last four weeks, equatorial SSTs were above-average across the Pacific and Indian Oceans. Also, above-average SSTs covered large areas of the Northern Hemisphere subtropics.

Click image to enlarge. Source: Climate Prediction Center / NCEP

Weekly SST Departures (°C) for the Last Four Weeks

• During the last four weeks, the largest positive SST anomalies have expanded eastward across the equatorial Pacific Ocean.
• During the last 30 days, equatorial SST anomalies have increased across much of the across the eastern equatorial Pacific.

Central & Eastern Pacific Upper-Ocean (0-300 m) Weekly Heat Content Anomalies
Since April 2009, the upper-ocean heat content has been above average across the eastern half of the equatorial Pacific Ocean. The heat content was previously below-average from mid-August 2008 through March 2009, with a minimum reached in late December 2008.

Click image to enlarge. Source: Climate Prediction Center / NCEP

Click image to enlarge. Source: Climate Prediction Center / NCEP

Click image to enlarge. Source: Climate Prediction Center / NCEP

Click image to enlarge. Source: Climate Prediction Center / NCEP

Click image to enlarge. Source: Climate Prediction Center / NCEP

Atmospheric Circulation over the North Pacific & North America During the Last 60 Days

During the first half of November, a nearly zonal pattern of above-average heights over the mid-latitudes was observed with anomalous troughing over the higher latitudes. This pattern led to above-average temperatures across much of North America and below-average temperatures in Alaska. From late November to the first half of December, the anomalous zonal pattern of above-average heights at mid-latitudes was replaced by strong anomalous troughs across the N. Pacific and much of N. America and above-average heights near Alaska. This pattern led to below-average temperatures across the U.S. and Canada and above-average temperatures over Alaska. Click image to enlarge. Source: Climate Prediction Center / NCEP

Pacific Niño 3.4 SST Outlook

• The models continue to disagree on the eventual strength of El Niño, but nearly all indicate at least a moderate strength El Niño (3-month average greater than +1.0°C) through January-February-March 2010.

• After peaking, the majority of models indicate Niño-3.4 will gradually weaken, but that El Niño will continue into April-May-June 2010. [International Research Institute (IRI) for Climate and Society (updated 17 Dec 2009).]

Summary

• 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.
• Based on current observations and dynamical model forecasts, El Niño is expected to continue and last at least into the Northern Hemisphere spring 2010.

Information and images on this page are sourced from Climate Prediction Center/NCEP/NOAA. Edited by FEWW

Related Links:

• Climate Locked into ‘Unending’ El Niño?
• What Florida Might Look Like in 2014
• SE Australia Toasted Brown
• UK Flooding
• Speaking of El Niño, OLR Anomalies in Australia
• El Niño Update [16 Nov 2009]
• Recognizing El Niño
• El Niño and La Niña: Tracing the Dance of Ocean and Atmosphere
• TAO Diagrams
• El Niño Forecasts

El Niño Updates:

• El Niño Weekly Update [7 Dec 2009]
• El Niño Update [30 Nov 2009]
• El Niño [Main Page and Links Archive]