Parameter Tree:
EARTH SCIENCE > CLIMATE INDICATORS > ATMOSPHERIC/OCEAN INDICATORS > TELECONNECTIONS > PACIFIC/NORTH AMERICAN (PNA) PATTERN

Definition:
The PNA pattern is one of the most prominent modes of low-frequency
variability in the Northern Hemisphere extratropics, appearing in all
months except June and July. The PNA pattern reflects a quadripole
pattern of height anomalies, with anomalies of similar sign located
south of the Aleutian Islands and over the southeastern United
States. Anomalies with sign opposite to the Aleutian center are
located in the vicinity of Hawaii, and over the intermountain region
of North America (central Canada) during the Winter and Fall (Spring).


Reference:
From: NOAA/NCEP:
http://www.cpc.ncep.noaa.gov/data/teledoc/pna.html