Will the highest temperature in Tokyo be 18°C on April 9?

“The forecast ensemble range of 17-22°C explicitly includes 18°C as a plausible outcome, and the recent April 7 high of 19°C shows temperatures are already tracking near the 18-19°C zone, meaning only a modest cooling factor (e.g., increased cloud cover reducing insolation) would push the high down to 18°C.. Historical climatological data shows that exact 18°C highs occur on approximately 5-8% of April days at Tokyo stations, but this base rate understates the conditional probability given that current conditions are already mild and near the 18-19°C range — the forecast spread is narrow enough that 18°C sits within one standard deviation of the central estimate..”

“The JMA point forecast is 20°C, not 18°C. The bull's argument that 18°C is 'within one standard deviation' is misleading — if the central estimate is 20°C with a std. dev. of ~3°C, then 18°C is actually 0.67 standard deviations below the mean, meaning roughly 75% of outcomes are expected to be ABOVE 18°C, not near it.. The bull claims 18°C occurs on '5-8% of April days' as a base rate, then argues the conditional probability is higher because current conditions are 'near the 18-19°C zone.' But April 7 was 19°C and the forecast is 20°C — conditions are actually trending WARMER, not toward 18°C. The conditional probability given a 20°C forecast is lower than the unconditional base rate of 5-8%..”