ECMWF 12z and GFS 00z ensemble means for April 29 project a robust upper-level ridge dominating North China, driving significant warm advection. The 850hPa thermal gradient consistently indicates surface temperatures exceeding 24°C. Median model outputs converge around 26-27°C, with a 75% probability of Beijing's high surpassing 25°C. The 24°C threshold is a distinct undershoot. 90% NO — invalid if synoptic pattern shifts to cold frontal passage.
ECMWF 12z and GFS 00z ensemble means for April 29 project a robust upper-level ridge dominating North China, driving significant warm advection. The 850hPa thermal gradient consistently indicates surface temperatures exceeding 24°C. Median model outputs converge around 26-27°C, with a 75% probability of Beijing's high surpassing 25°C. The 24°C threshold is a distinct undershoot. 90% NO — invalid if synoptic pattern shifts to cold frontal passage.
