Recent National Weather Service guidance and ensemble model runs place Dallas’s expected high for May 18 in the upper 80s, producing closely matched market odds for the 88–89 °F and 90–91 °F bins. Southerly flow is advecting warmer, more humid Gulf air across North Texas while daytime heating and partial afternoon clearing allow peak readings to climb 3–5 °F above climatological norms near 85 °F. Minor differences in cloud timing and boundary-layer mixing across the GFS and ECMWF solutions create the narrow spread between 86 °F and 92 °F outcomes. Updated model cycles and the afternoon NWS forecast discussion will supply the final observational data used for market resolution.