Pacific decadal oscillation stays cool, resists El Nino forecasts (for now) Discussion: The long-standing (2020-23) cool phase of the Pacific decadal oscillation (-PDO) should be reversing warmer given El Nino forecasts by most dynamic models and ongoing observations yielding warming in the equatorial East Pacific surface and subsurface. However, -PDO intensified during March and is running cooler than forecast by analogs (Fig. 1). The analog forecast suggests PDO stays in the cool phase in 2023 which lowers risk of El Nino forming. The PDO analog years render neutral ENSO phase for 2023-24 (Fig. 2). The diagnostic which is key to PDO phase in 2023 is whether the 10-year marine heat wave now located north of Hawaii (Fig. 3) can shift east which is necessary to reverse PDO to the warm phase and guarantee El Nino development. Despite aggressive El Nino forecasts by dynamic models, the required push of the MHW into the West Coast is not indicated (Fig. 4). Fig. 1: The Pacific decadal oscillation index analog forecast through 2024. Fig. 2: The PDO analog years and attendant ENSO phase using Nino34 SSTA index. Fig. 3: Daily SSTA forecasts reveal the cool phase of the Pacific decadal oscillation and the Northeast Pacific marine heat wave. Fig. 4: Global SSTA forecast for August 2023 by ECMWF.