Pacific Transition (RPCA daily)

CPC-method rotated-PCA Pacific Transition pattern rebuilt from ERA5 500-hPa height, daily least-squares fit on patterns interpolated to the day. Positive: highs west of Hawaii and over western North America, lows over the Gulf of Alaska and the south-east US. August–September only. — Barnston & Livezey 1987; NOAA CPC