Recent National Weather Service model runs indicate a high near 89–91°F for Dallas on May 17 amid southerly flow of warm, moist Gulf air, supporting the tight market clustering around 86–89°F. Afternoon convective development and associated cloud cover could temper peak readings by enhancing mixing and limiting solar heating, while a modest dew-point surge may boost heat index without raising dry-bulb maxima. These short-term factors—temperature advection, boundary-layer moisture, and timing of thunderstorm initiation—explain why traders assign comparable weight to the 86–87°F and 88–89°F bins, with only modest probability extending above 90°F or below 85°F. Updated model guidance and surface observations tomorrow morning will refine the exact maximum before resolution.