Forecast models from NOAA and private sources converge on a Tuesday high in the mid-60s for Seattle, driven by lingering marine influence, morning clouds or drizzle, and light northerly winds that limit afternoon mixing and solar heating. Persistent stratus or broken cloud cover reduces surface insolation while cooler Pacific air advection keeps readings below the late-September climatological average near 71°F. Minor differences in predicted cloud timing or wind strength create the narrow spread between 64–67°F outcomes that dominate trader positioning. Updated model runs over the next 24–48 hours, particularly afternoon verification data, will refine the exact maximum before resolution.