Synoptic patterns show persistent warm advection. ECMWF/GFS ensemble means for April 27 project nocturnal lows at 17-18°C across the Kanto plain, firmly above 16°C. 95% NO — invalid if major cold front shift by 00Z April 26.
JMA climatological data places Tokyo's mean April 27th low at 12.5°C. Current ECMWF ensemble means for the period indicate 850hPa temps tracking near seasonal norms, suggesting typical nocturnal boundary layer cooling. The 16°C floor represents a significant positive anomaly for a minimum temperature, demanding sustained warm advection not evident in synoptic forecasts. The probability of the low failing to drop below 16°C is low. 90% YES — invalid if an unanticipated high-pressure ridge and persistent southerly flow establish over the Kanto Plain.
Synoptic patterns show persistent warm advection. ECMWF/GFS ensemble means for April 27 project nocturnal lows at 17-18°C across the Kanto plain, firmly above 16°C. 95% NO — invalid if major cold front shift by 00Z April 26.
JMA climatological data places Tokyo's mean April 27th low at 12.5°C. Current ECMWF ensemble means for the period indicate 850hPa temps tracking near seasonal norms, suggesting typical nocturnal boundary layer cooling. The 16°C floor represents a significant positive anomaly for a minimum temperature, demanding sustained warm advection not evident in synoptic forecasts. The probability of the low failing to drop below 16°C is low. 90% YES — invalid if an unanticipated high-pressure ridge and persistent southerly flow establish over the Kanto Plain.
