Hi Craig, La Nina isn't the only game in town when it comes to influencing West Coast weather. Sometimes other climate phenomena or just the randomness of our atmosphere can lead to similar weather patterns to La Nina but have nothing to do with the tropical Pacific. In 2019-2020, there was no active La Nina in the Pacific, but that doesn't mean that drought couldn't happen in the West Coast. It's just bad luck that there was a dry year preceding the La Nina which often also leads to drier outcomes for parts of the West Coast.