National Weather Service and private forecast models converge on a high near 103–105°F for Dallas on August 17 under a strong subtropical ridge that maintains clear skies, light southerly flow, and minimal mixing overnight. Dew points near 75°F will support heat indices above 105°F, while the absence of a frontal passage or significant cloud cover keeps daytime maxima elevated. Historical August climatology shows typical highs of 95–97°F, so current conditions represent a 6–8°F anomaly driven by ridging rather than transient moisture. Small model spread in boundary-layer moisture and wind speed accounts for the tight clustering of market-implied odds between the 102–103°F and 104–105°F bins, with slight upside risk if afternoon heating exceeds guidance.