Structural Concentration of Extreme Precipitation in High-Ω States (Tokyo) — Minimal Reproducible Test

This record provides a minimal, reproducible test of structural concentration in a weather domain. Using daily precipitation data (Open-Meteo, Tokyo), we test whether extreme precipitation events concentrate in a predefined high-Ω regime under fixed, ex-ante definitions. Result: P(collapse | high Ω): 0.48 Baseline: 0.050 Ratio: 9.47× Ω is defined as: Ω = I × G I: rolling standard deviation of precipitation (window = 30) G: absolute daily change in precipitation Definitions: - high Ω = Ω > q(0.99) (execution layer) - collapse = precipitation > q(0.95) All definitions are fixed prior to evaluation and are independent (non-circular). This is not a predictive model. No optimization is performed. The result reports conditional frequency, not timing prediction. Reproducibility: https://colab.research.google.com/drive/1hCA98FhUjrJd9xYC9c02qm6pjcGpWhWP Data: Open-Meteo (public) Code: included in the Colab notebook