Since late January, the Pacific North America (PNA) index has shifted to a (mostly) steady negative phase. A brief positive phase is with us now, but strengthening negative phase returns in the latest 15-day forecast. The -PNA pattern occurs when an upper-level troughing in the jet stream pattern occurs just off the North America West Coast. The persistence of the -PNA pattern has caused the Northeast Pacific to cool, the Northeast Pacific marine heat wave (MHW) to shift westward and reinvigorate the cool phase of the Pacific decadal oscillation (-PDO).