When Does the Lorenz 1963 Model Exhibit the Signal?To?Noise Paradox?

Seasonal prediction systems based on Earth System Models exhibit a lower proportion of predictable signal to unpredictable noise than the actual world. This puzzling phenomena has been widely referred as signal-to-noise paradox (SNP). Here, we investigate SNP in conceptual framework seasonal system Lorenz, 1963 Model (L63). We show that is not apparent L63, if uncertainty assumed for initialization ensemble equal starting conditions. However, overestimates conditions, apparent. In these experiments metric used quantify also shows clear lead-time dependency subseasonal timescales. therefore, formulate alternative hypothesis previous studies could be related magnitude initial spread.