Forecast models from the National Weather Service and private services indicate an upper-90s high for Houston on August 27 amid lingering high pressure, with southwest flow and dew points near 70°F supporting heat indices above 100°F. A weak frontal boundary approaching from the north is introducing modest moisture and instability, raising afternoon thunderstorm chances to 20-30% that could enhance cloud cover and limit peak heating. This uncertainty around convective timing and coverage explains the tight clustering of market probabilities on 94-97°F outcomes, as even brief storms or thicker clouds could trim highs by 2-4°F from sunnier baselines near 98-100°F while historical late-August averages sit around 92°F. Updated model runs and NWS briefings on storm initiation will be key near-term drivers.