I would not expect El Nino to have a significant influence on the PDO index until winter, when El Nino would be expected to have a big impact on Aleutian low strength and location. A turn to a positive PDO index would be an indication that the North Pacific atmosphere and ocean are responding to El Nino in the expected way, but it's important to keep in mind that there's a component of the PDO unrelated to El Nino that may not be connected with El Nino impacts.