Climatological mean max for Sao Paulo in early May sits at 23.8°C. Current ECMWF ensemble guidance for D+10 shows high confidence in a negative thermal anomaly, driven by post-frontal advection. The 850hPa temperature profiles suggest persistent upper-level troughing, limiting diurnal warming. Surface dew points remain elevated, implying increased cloud cover and suppressed insolation. This convergence of factors strongly pegs the high below the threshold. 90% YES — invalid if a strong northerly advection develops post-00Z GFS run.
Climatological mean max for Sao Paulo in early May sits at 23.8°C. Current ECMWF ensemble guidance for D+10 shows high confidence in a negative thermal anomaly, driven by post-frontal advection. The 850hPa temperature profiles suggest persistent upper-level troughing, limiting diurnal warming. Surface dew points remain elevated, implying increased cloud cover and suppressed insolation. This convergence of factors strongly pegs the high below the threshold. 90% YES — invalid if a strong northerly advection develops post-00Z GFS run.
