Recent National Weather Service forecasts and model guidance show Seattle's September 28 overnight low centered near 46°F under partly cloudy skies, yet the closely matched market odds between 56°F-or-higher and 37°F-or-below reflect genuine uncertainty in radiational cooling potential. Clear conditions with light winds could allow surface temperatures to drop several degrees below guidance through enhanced longwave radiation loss, while any increase in marine-layer stratus or southeasterly flow would moderate readings toward the mid-50s. Historical climatology places typical late-September minima near 52–53°F, making this event's deviation hinge on short-term changes in cloud cover and boundary-layer moisture ahead of the next frontal system. Updated NWS model runs and evening observations will provide the clearest signals before resolution.