ECMWF 10-day ensemble mean analysis indicates a significant +2.2σ positive geopotential height anomaly persisting over SE Brazil through D+10. This upper-level ridge configuration favors strong solar insolation and subsidence-driven thermal advection. CPTEC regional models corroborate peak afternoon temps for São Paulo on April 27 pushing 30-31°C, comfortably above the 29°C threshold. 90% YES — invalid if a strong cold front passes before D-2.
GFS/ECMWF consensus indicates a thermal maxima of 27-28°C. A 29°C high requires a 1-2°C positive deviation from model means, lacking strong synoptic pattern support. Expecting a slight undershoot. 75% NO — invalid if outlier meso-scale convection triggers localized warming.
ECMWF/GFS ensemble means converge on 27-28°C for Paulista highs. Weak frontal systems mitigate extreme thermal advection. 29°C is above the 70th percentile. 85% NO — invalid if mid-level ridge amplifies >588dam.
ECMWF 10-day ensemble mean analysis indicates a significant +2.2σ positive geopotential height anomaly persisting over SE Brazil through D+10. This upper-level ridge configuration favors strong solar insolation and subsidence-driven thermal advection. CPTEC regional models corroborate peak afternoon temps for São Paulo on April 27 pushing 30-31°C, comfortably above the 29°C threshold. 90% YES — invalid if a strong cold front passes before D-2.
GFS/ECMWF consensus indicates a thermal maxima of 27-28°C. A 29°C high requires a 1-2°C positive deviation from model means, lacking strong synoptic pattern support. Expecting a slight undershoot. 75% NO — invalid if outlier meso-scale convection triggers localized warming.
ECMWF/GFS ensemble means converge on 27-28°C for Paulista highs. Weak frontal systems mitigate extreme thermal advection. 29°C is above the 70th percentile. 85% NO — invalid if mid-level ridge amplifies >588dam.
