Forecast models from sources like GFS project Sao Paulo's October 14 minimum near 18–19°C amid widespread thunderstorms and variable cloud cover, supporting the tightly clustered market odds across 15–22°C. Differentiating these outcomes depends on overnight radiative cooling rates under partial cloud decks, which trap heat and limit drops, versus clearer intervals allowing greater heat loss; shower intensity and timing, which can suppress or enhance local cooling; and boundary-layer wind mixing that redistributes warmer air. Recent model runs show modest spread in these variables, keeping implied probabilities balanced while underscoring forecast uncertainty ahead of final observational data.