National Weather Service forecast models and supporting numerical guidance converged overnight on a daily high of 58–59 °F at Seattle-Tacoma International Airport, driving the market’s near-certain implied probability for that bin. Persistent onshore marine flow from the cool Pacific waters has maintained a strong temperature inversion and extensive low-level stratus, capping afternoon warming in line with mid-May climatology for the Puget Sound region. This pattern aligns with La Niña-enhanced spring conditions that favor cooler, cloudier days across the Pacific Northwest. The only realistic shifts would require an abrupt ridge breakdown or offshore flow reversal, neither of which appears in the latest model runs before the observation window closes.