Synoptic analysis indicates a dominant post-frontal air mass over Sao Paulo for May 5, driving thermal values below the 26°C threshold. Current ECMWF/GFS ensemble means cluster consistently in the 23-25°C range, tightly grouped without significant positive thermal anomaly. Climatological normals for early May in the region further support a mean max Td around 22.5°C. A 26°C high necessitates an unforecasted strong subsidence or northerly advection. 90% NO — invalid if mid-tropospheric ridging intensifies unexpectedly.
Synoptic analysis indicates a dominant post-frontal air mass over Sao Paulo for May 5, driving thermal values below the 26°C threshold. Current ECMWF/GFS ensemble means cluster consistently in the 23-25°C range, tightly grouped without significant positive thermal anomaly. Climatological normals for early May in the region further support a mean max Td around 22.5°C. A 26°C high necessitates an unforecasted strong subsidence or northerly advection. 90% NO — invalid if mid-tropospheric ridging intensifies unexpectedly.
