Recent National Weather Service forecasts highlight an approaching upper-level low strengthening over the western Atlantic, driving a sharp increase in thunderstorm coverage and cloudiness across South Florida on September 17. This pattern favors scattered to likely storms through the afternoon, with 70–90% precipitation probabilities that can reduce solar insolation and cap daytime highs. Model guidance and local observations point to maximum temperatures most likely in the mid-to-upper 80s°F, where the balance between easterly flow, boundary-layer moisture, and convective timing determines whether peaks reach the 88–89°F bin or remain closer to 86–87°F. Historical September climatology shows similar synoptic setups often suppress maxima by 2–4°F relative to clearer days, though exact resolution hinges on storm initiation timing and any model adjustments in the next 48 hours.