In a colder base state the nao was king. But a +pdo -nao could be cold/dry. So a lot of our snowiest years were -pdo -nao. A -pdo +nao was always a bad bad bad pattern though.
Problem now imo, we’ve warmed too much for a -pdo -nao to work the same as it used too. The pac storms are coming in too amplified and dig the western trough more. The warmer gulf and atl pump the SER more. The SER links with the nao. Everything gets shifted north. It seems now the epo/pna have become more important. We’ve lost a -pdo -nao as a big snow producer combination.