Robust GFS/ECMWF ensemble output indicates a high-confidence thermal advection event for April 27 in Sao Paulo. The 00z and 12z runs converge on a peak diurnal temp of 26-27°C, well supported by a developing upper-level ridge and post-frontal subsidence. Climatological anomalies suggest a +2σ departure from mean late-April highs. The market's implied probability for <=25°C is undervalued given this synoptic setup. 85% NO — invalid if a sudden pre-event frontal passage drops dew points significantly.
Robust GFS/ECMWF ensemble output indicates a high-confidence thermal advection event for April 27 in Sao Paulo. The 00z and 12z runs converge on a peak diurnal temp of 26-27°C, well supported by a developing upper-level ridge and post-frontal subsidence. Climatological anomalies suggest a +2σ departure from mean late-April highs. The market's implied probability for <=25°C is undervalued given this synoptic setup. 85% NO — invalid if a sudden pre-event frontal passage drops dew points significantly.
