August 9, 2011

A pattern of unusually warm and cold spots alternated around high northern latitudes in 2010—a classic sign of the negative phase of the Arctic Oscillation.

globes showing pressure patterns during positive and negative phases of the Arctic Oscillation
March 28, 2011

Large-scale shifting of the weight of the atmosphere between mid- and high latitudes creates climate patterns known as the Arctic and North Atlantic Oscillations. These patterns have a big influence on winter weather in the Eastern U.S.

February 8, 2011

Deep snow that fell across the Great Plains and the Northeast in late January and early February is the latest installment in the second very wintry winter in a row for the eastern U.S.

March 26, 2010

NOAA's Climate Scene Investigators analyzed why the mid-Atlantic region had record-setting snowstorms this winter. The team looked for but found no human "fingerprints" on the severe weather. Instead, they fingered two naturally occurring climate patterns as co-conspirators in the case.

September 1, 2009

The Pacific-North American teleconnection pattern influences regional weather by affecting the strength and location of the East Asian jet stream, and subsequently, the weather it delivers to North America.

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. 

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