August 30, 2009

The Arctic Oscillation (AO) refers to an atmospheric circulation pattern over the mid-to-high latitudes of the Northern Hemisphere. The most obvious reflection of the phase of this oscillation is the north-to-south location of the storm-steering, mid-latitude jet stream.

August 30, 2009

Over the span of days or weeks, the strength of surface air pressure over the North Atlantic seesaws between Iceland and the Azores Islands. The shifting pressure reflects changes in atmospheric circulation that have a big impact on mid-latitude weather in the U.S. and Europe. 

March 22, 2018

In this week's ENSO blog, Tom DiLiberto gets all judgy over the 2017-2018 Winter Outlook—using science of course.

MJO impacts on 2017-18 winter
February 22, 2018

How this winter's temperature swings may have been partially driven by the Madden Julian Oscillation or MJO.  

October 23, 2017

The Climate Prediction Center's Mike Halpert dives into the 2017-2018 winter outlook, and talks about how La Niña winters today are different from La Niña winters of the past. 

August 10, 2017

Why the tropical Pacific is exceptionally ENSO-Neutral and what does it mean. 

March 2, 2017

In this installment of our Beyond the Data blog, Carl Schreck talks about how a tropical climate pattern called the MJO left its fingerprints all over California's soaking rains and Boston's recent snowstorm.

PMM SST Anomoly (480 px)
November 23, 2016

Are sea surface temperatures located north of the equator important for El Niño or La Niña development?  Yes!  Introducing the Pacific Meridional Mode.  

August 25, 2016

Understanding the Pacific Decadal Oscillation (PDO) as multiple layers of ice cream.  And how is it related to the El Niño-Southern Oscillation?  

April 28, 2016

Guest blogger Amy Butler explains how changes in the stratospheric polar vortex can influence the "usual" effects of El Niño on the climate in the Northern Hemisphere.

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