"0e53e397-7836-45ec-bc62-0d54f9f176e5" . "PACIFIC/NORTH AMERICAN (PNA) PATTERN"^^ . "The PNA pattern is one of the most prominent modes of low-frequency\nvariability in the Northern Hemisphere extratropics, appearing in all\nmonths except June and July. The PNA pattern reflects a quadripole\npattern of height anomalies, with anomalies of similar sign located\nsouth of the Aleutian Islands and over the southeastern United\nStates. Anomalies with sign opposite to the Aleutian center are\nlocated in the vicinity of Hawaii, and over the intermountain region\nof North America (central Canada) during the Winter and Fall (Spring)."^^ . .