Latest National Weather Service forecasts for Seattle point to a daily high in the mid- to upper 70s on August 17, driven by weak ridging that permits modest warming beneath a stable airmass while persistent onshore flow from the Pacific keeps marine air moderating temperatures. This pattern aligns with typical late-summer conditions, where the Puget Sound convergence zone and stratus influence can trim afternoon peaks by several degrees relative to inland sites. Ensemble model spreads and slight variations in boundary-layer mixing create the tight clustering around 76–81°F bins, with lower probabilities assigned to outliers that would require stronger offshore flow or delayed marine intrusion. Updated model runs and NWS briefings ahead of the 24-hour forecast window remain the key data points likely to refine trader positioning.