Latest National Weather Service guidance and ensemble model consensus point to a Seattle high near 77°F on August 19, underpinning the closely matched 76–79°F outcomes that together exceed 66% implied probability. A mid-level trough crossing the region late Monday into Tuesday is expected to limit daytime warming through increased cloud cover and onshore flow from the Pacific, while the marine layer over Puget Sound further moderates peak temperatures. These conditions align with late-August climatology, where average highs reach 77–79°F. Subtle variations among model runs—particularly the timing and strength of marine intrusion versus any residual subsidence warming—account for the narrow spread between the two leading bins rather than a single dominant outcome. Updated NWS forecasts tomorrow morning will likely refine resolution criteria tied to official observations at Sea-Tac.