Recent National Weather Service model runs project a daytime high in Dallas on May 18 near 86–89 °F under partly sunny skies with a 30–55 % chance of afternoon thunderstorms. These convective clouds and any associated rain-cooled downdrafts are the main factors keeping the 88–89 °F and 90–91 °F bins in a near tie at roughly 27–29 % implied probability, while the 92 °F-plus outcome remains competitive at 27 %. Typical early-May climatology places Dallas highs at 84–86 °F, so any delay in storm initiation or stronger southerly flow could push readings into the low 90s; conversely, earlier or heavier precipitation would cap them lower. Updated short-range guidance and local mesonet observations expected over the next 48 hours will determine which side of 90 °F ultimately prevails.